Low Molecular Weight Polypeptides Research Articles

Plum blossom low molecular weight polypeptide protects HaCaT cells against UVB-induced oxidative damage in vitro and underlying mechanism.

Increasing amounts of ultraviolet radiation occur as ozone depletion causes the earth's ozone layer to be destroyed, making antioxidant efficacy a research hotspot. Previous studies on plum blossom have mostly focused on Volatile Oils, Flavonoids, Phenylpropanoids, and other compounds, whereas few studies have focused on low molecular weight polypeptide (LMWP) of plum blossom. This research provides a reference for the deep processing and utilization of plum blossom. (a) Plum blossom low molecular weight polypeptides protect HaCaT cells against UVB-induced oxidative damage in vitro and the underlying mechanism. (b) Improve the theoretical basis for the intense processing and utilization of plum blossom. The safe concentration of LMWP and the survival rate of HaCaT cells were determined using the CCK-8 experiment. The fluorescence intensity of reactive oxygen species (ROS) was identified using the dichlorofluorescin diacetate (DCFH-DA) method; Superoxide dismutase (SOD) and malondialdehyde (MDA) concentrations were measured in ruptured cells; Western blot analysis was used to examine the expression levels of three proteins: nuclear factor E2-related factor 2 (Nrf2), heme oxygenase 1 (HO-1), and benzoquinone oxidoreductase 1 (NQO-1). It was noted that a certain concentration of LMWP could promote cell proliferation. In oxidatively damaged HaCaT cells, SOD levels and survival rates were markedly reduced, but ROS and MDA levels were elevated. However, after treatment with LMWP, the survival rate of the cells and SOD levels were markedly increased, and the levels of ROS and MDA were markedly decreased. As shown by Western blotting, the model group exhibited lower levels of Nrf2, HO-1, and NQO-1 expression than the control group, whereas LMWP-treated cells had significantly higher levels of Nrf2, HO-1, and NQO-1 expression than their model-treated counterparts. LMMP can effectively protect HaCaT cells against oxidative damage in vitro induced by UVB, and the underlying mechanism is linked to the activation of the transcription factor Nrf2.

Detection of IgG Anti-Giardia duodenalis Antibodies in Sera by Indirect Immunofluorescence and Western Blotting Assays.

Serological assays are alternative laboratory tools for the diagnosis of parasitic infections. The aim of this work was to evaluate the performance of the indirect fluorescent antibody test (IFAT) and Western blotting (WB) for the detection of IgG anti-Giardia antibodies in human sera. Sera from individuals infected with Giardia duodenalis, other parasites or non-parasitized were selected for serological assays. Ninety-seven sera were tested by IFAT at 1:20 and 1:40 dilutions and of these, 40 samples were also analyzed by WB. The sensitivity and specificity of the IFAT was 97% and 46.9% at 1:20 sera dilution, and 39.4% and 59.4% at 1:40 sera dilution. The low molecular weight polypeptides fractions of 25kDa, 27-31kDa and 45-55kDa were the most frequently identified by the sera of individuals infected with G. duodenalis, along with low cross-reactivity, presenting an individual sensitivity of 42.8%, 50.0% and 57.1%, and specificity of 83.3%, 83.3% and 91.7%, respectively. The highest overall sensitivity of WB (85.7%) was based on the immunoreactivity of sera with at least one of those proteins. The concordance between the detection of G. duodenalis in feces by microscopy and the WB results was considered substantial (Kappa = 0.61). Constant exposure to Giardia infection throughout a lifetime can maintain high levels of specific antibodies in serum, even without active infection. Moreover, proteins found in intestinal amoebas may hinder the serological diagnosis of giardiasis in endemic areas due to cross-reactivity, which can be partially solved using Giardia low molecular weight proteins.

A combination of Sephadexes for the milk whey protein fractions isolation

Whey proteins perform important biological functions. They can also be a source of numerous natural bioactive peptides that have a positive effect on various physiological systems of the body. For research and usage of this phenomenon, the question of these proteins isolating with saving of their structure and biological functions is relevant. Considering the significant difference in molecular weights, gel filtration is a promising method. The purpose of the study was the fractionation of milk whey proteins using gel filtration with a combination of different dextran gels. We used in the work milk whey proteins after isoelectric precipitation of casein and isolation of low molecular weight peptides by gel filtration on Sephadex G-25. The first gel filtration of the whey protein preparation was performed on a column with Sephadex G-150. For further fractionation were used three sectors from the first two chromatographic peaks obtained by gel filtration on Sephadex G-150. The first peak contains high molecular fractions of proteins eluting with a volume close to the free volume of the chromatographic column. The second asymmetric peak consists mainly of β-lactoglobulin and α-lactalbumin mixture. The third peak includes low molecular weight polypeptides and peptides that are not fixed in a polyacrylamide gel. The combined chromatographic fractions of three sectors from the first two chromatographic peaks were re-fractionated on a G-100 column. Electrophoretic analysis of chromatographic fractions after repeated chromatography of milk whey proteins confirmed the feasibility of choosing a certain sequence of sephadex. At the same time, the yield of β-lactoglobulin fraction increases by 12 ± 1 %, and α-lactalbumin by 9 ± 1 % compared to the results obtained by repeated gel filtration on one Sephadex (G-100). The degree of purification of β-lactoglobulin and α-lactalbumin, according to the densitometry, was 93 ± 5 % and 77 ± 4 %, respectively.

Insights into the growth parameters, mineral composition, protein and UHPLC–QTOF–LC/MS‐based non‐targeted metabolomic fingerprints of wheatgrass as a function of photoperiod and temperature

SummaryWheatgrass juice powder (WJP) obtained from four Indian wheat varieties grown under different photoperiod and temperature conditions were examined for growth parameters, chlorophyll content, mineral composition, protein and metabolomic profile. The percentage yield and total chlorophyll content of WJP varied from 2.5% to 9.12% and 1.08 to 4.76 mg g−1, respectively. The WJP obtained from PBW‐752 showed the highest yield and total chlorophyll content. The mineral composition (Na, K, Ca and Mg) of WJP also showed variation with different photoperiod and temperature conditions. The electrophoretic pattern of total soluble proteins of WJP showed variability in the accumulation of high and low molecular weight polypeptides against different photoperiod and temperature conditions. The comprehensive metabolites profile of WJP was analysed by UHPLC–QTOF–liquid chromatography/mass spectrometry. Based on the retention times and m/z values, 1012 feature peaks in positive ionisation mode were detected. The metabolomic profile of WJP revealed 180 different classes of primary and secondary metabolites.

The Study of Type I Collagen by Immunoblotting in Samples of Bone-Plastic Biomaterials

The type I collagen was studied in samples of two types of osteoplastic materials produced in the Biotech Research Institute of the Samara State Medical University using immunoblotting. The demineralized samples used in the work were compact bone powder and crushed material of human cancellous bone tissue. Collagen and its polypeptides were separated in a 5% polyacrylamide gel with 3.6 M urea according to the method of Hayashi and Nagai (1979). The advantage of the method is the separation under these conditions of type I and III collagen, as well as the α1(I) and α2(I) chains of type I collagen. Immunoblotting was carried out by diffusion method according to the method of Towbin et al. (1979) using nitrocellulose membranes (Santa Cruz, USA). Primary goat polyclonal antibodies to denatured collagen, 1:500 dilution (Millipore) were used. Peroxidase-conjugated secondary antibodies (mouse vs. goat), 1:80000 dilution (Sigma) were used also. It has been established that the bulk of the compact bone protein is localized between the α1- and α2-fractions of collagen. In samples of cancellous bone tissue, a molecular reduction of the protein is noted. Protein macromolecules with a gradually decreasing molecular weight and low molecular weight polypeptides migrating in the gel with a wide front up to the indicator line are detected. Due to the low specificity of osteoblast integrins in regenerating bone tissue, collagen polypeptides, as well as protein molecules retained in implants, can act as inducers of synthetic processes occurring in osteoblast nuclei. Protein fragmentation products in the implant can act as signaling molecules that trigger cascades of enzymatic reactions and intracellular signaling pathways.

Oligonol ameliorates liver function and brain function in the 5 × FAD mouse model: transcriptional and cellular analysis.

Alzheimer's disease (AD) is a common neurodegenerative disease worldwide and is accompanied by memory deficits, personality changes, anxiety, depression, and social difficulties. For treatment of AD, many researchers have attempted to find medicinal resources with high effectiveness and without side effects. Oligonol is a low molecular weight polypeptide derived from lychee fruit extract. We investigated the effects of oligonol in 5 × FAD transgenic AD mice, which developed severe amyloid pathology, through behavioral tests (Barnes maze, marble burying, and nestle shredding) and molecular experiments. Oligonol treatment attenuated blood glucose levels and increased the antioxidant response in the livers of 5 × FAD mice. Moreover, the behavioral score data showed improvements in anxiety, depressive behavior, and cognitive impairment following a 2-month course of orally administered oligonol. Oligonol treatment not only altered the circulating levels of cytokines and adipokines in 5 × FAD mice, but also significantly enhanced the mRNA and protein levels of antioxidant enzymes and synaptic plasticity in the brain cortex and hippocampus. Therefore, we highlight the therapeutic potential of oligonol to attenuate neuropsychiatric problems and improve memory deficits in the early stage of AD.

Effects of Phytochelatin-like Gene on the Resistance and Enrichment of Cd2+ in Tobacco.

Phytochelatins (PCs) are class III metallothioneins in plants. They are low molecular-weight polypeptides rich in cysteine residues which can bind to metal ions and affect the physiological metabolism in plants. Unlike other types of metallothioneins, PCs are not the product of gene coding but are synthesized by phytochelatin synthase (PCS) based on glutathione (GSH). The chemical formula of phytochelatin is a mixture of (γ-Glu-Cys)n-Gly (n = 2-11) and is influenced by many factors during synthesis. Phytochelatin-like (PCL) is a gene-encoded peptide (Met-(α-Glu-Cys)11-Gly) designed by our laboratory whose amino acid sequence mimics that of a natural phytochelatin. This study investigated how PCL expression in transgenic plants affects resistance to Cd and Cd accumulation. Under Cd2+ stress, transgenic plants were proven to perform significantly better than the wild-type (WT), regarding morphological traits and antioxidant abilities, but accumulated Cd to higher levels, notably in the roots. Fluorescence microscopy showed that PCL localized in the cytoplasm and nucleus.

Peptides and low molecular weight polypeptides of Azadirachta indica seeds as new weapons against cancer cells and superbugs

BackgroundIn Ayurvedic practice, neem is an immensely important medicinal plant that's been part of traditional medications dating back to ˂ 5000 years. Its botanical name being A. indica while it is known as Nimba in Sanskrit. Prior to written records, all the parts of neem were used to treat and cure various ailments, infections, fevers, etc. Such wide range of application has led to it being termed “the village pharmacy.” The current study reports for the first time extraction and biological activity evaluation of these AMPs and polypeptides derived from the seeds of A. indica. Materials and methodThe present study intends to be the first to evaluate the antimicrobial and antitumoral properties of peptides and polypeptides on cancer cell lines from the total protein extracted from neem plant seeds by means of cell and molecular biology approaches. Protein extraction and precipitation was performed applying our optimized/standardized protocols. The antimicrobial activity was assayed efficiently using PAG-ADA method. The anticancer property of the extracted protein was detected by MTT assay, while MALDI-TOF/TOF and FTIR were performed to characterize the structure of these AMPs and polypeptides. ResultsTwo standardized protein extraction procedures were employed and the protein obtained from these two procedures were 262.67 ± 6.12 and, 248.7 ± 9.49 mg/g of seeds, respectively. Our study reports two novel antimicrobial peptides, and four polypeptides extracted from the dried seeds of A. indica. Further, we confirmed the bactericidal activity of the peptides and polypeptides extracted from A. indica seeds using PAG-ADA techniques against six different human pathogens. Remarkably high zone of growth inhibition against MRSA (30.0 ± 1.52) mm was noted. On the other hand, the total protein extracted possessed excellent anticancer activity with low IC50 values of 33.46 ± 2.63 and 20.83 ± 1.60 μg/mL against HeLa cells and 6.94 ± 0.10 and 6.87 ± 0.90 μg/mL against BT549 cell lines at 24 and 48 h, respectively. ConclusionsAMPs and polypeptides extracted from seeds of the medicinal plant A. indica exhibited bactericidal activity against different bacterial pathogens. In addition, the extract possessed good anticancer activity against the cervical cancer and breast cancer cell lines. Therefore, these promising findings pave the way for identification of plant-based bioactives responsible for the anticancer and antimicrobial attributes.

Lubricant Biochemistry Affects Polyethylene Wear in Knee Simulator Testing

Lubricant composition has been shown to influence knee simulator wear. In the present study, three types of lubricants each having different biochemistries were used in knee simulator wear tests. Alpha-calf serum was diluted with either low-ion distilled water, phosphate-buffered saline solution (PBS), or PBS with hyaluronic acid (HA), all of which affected the polyethylene wear rate. Adding HA to the PBS lubricant increased the polyethylene wear rate 2-fold. Diluting alpha-calf serum with low-ion distilled water instead of PBS increased the polyethylene wear rate 2.3-fold. Since a boundary lubrication regime was considered likely to account for these differences, the degradation to the lubricants was also monitored. Changes to the lubricant composition affected the polypeptide degradation, constituent degradation, low-molecular weight polypeptide concentration, and consequently the polyethylene wear rate. A speculative colloid-mediated boundary lubrication model was suggested, and further support was obtained by performing additional tests with osteoarthritic human synovial fluid that indicated that polypeptide constituent fractions were affected by the wear test. Diluting the alpha-calf serum lubricants with PBS, using an antibiotic-antimycotic additive to inhibit bacterial growth, and including HA created a lubricant that was similar in biochemical characteristics to human osteoarthritic synovial fluid and produced linear penetration rates and surface pitting that were comparable to those seen clinically for the same type of total knee replacements. This lubricant was recommended for producing more clinically relevant knee wear simulator testing.

Development and validation of a novel LC-MS/MS assay for C-peptide in human serum

IntroductionC-peptide is used as a marker of endogenous insulin secretion in the assessment of residual β-cell function in diabetes and in the diagnostic workup of hypoglycemia. Previously developed LC-MS/MS methods to quantify serum concentrations of C-peptide have monitored intact peptide, which ionizes poorly. As a result, methods have leveraged immunoaffinity enrichment or two-dimensional chromatography. In this study, we aimed to use proteolysis during sample preparation to enhance the sensitivity of traditional LC-MS/MS. MethodsDue to the absence of arginine and lysine residues in C-peptide, we utilized Glu-C as the proteolytic enzyme in the method. After protein precipitation using acetonitrile and solid phase extraction with mixed anion exchange, lower molecular weight polypeptides were reduced, alkylated, and proteolyzed. The two amino-terminal peptide fragments, EAEDLQVGQVEand LGGGPGAGSLQPLALE, were monitored using multiple reaction monitoring in positive ion mode (Acquity ULPC-Xevo TQ-S, Waters). The former peptide was used for quantification and the latter for quality assurance. ResultsGlu-C was determined to be a reliable proteolytic enzyme with monotonic digestion kinetics.The assay was linear between 0.1 and 15 ng/mL and had a lower limit of quantification of 0.06 ng/mL. Total imprecision was 7.7 %CV and long-term imprecision at 0.16 ng/mL was 10.0%. Spike-recovery experiments demonstrated a mean recovery of 98.2 % (± 9.1 %) and the method compared favorably with a commercially available immunoassay and a reference measurement procedure. ConclusionProtein precipitation with solid phase extraction and proteolysis with Glu-C is a robust sample preparation method for quantification of C-peptide in human serum by LC-MS/MS.

Influence of high molecular weight polypeptides on the mouthfeel of commercial beer

Low malt beers have high sales volumes in Japan, but improving their mouthfeel, including softness, smoothness and decreasing astringency, is challenging because the compounds responsible remain unclear. In this study, beer was fractionated by preparative size-exclusion chromatography, with the polypeptide and maltodextrin fractions purified using solid-phase extraction and ion-exchange resin. Sensory data from a spike test showed that the mouthfeel (softness, smoothness, and reduced astringency) of low malt beer was improved both by the degree of polymerisation (DP) of maltodextrins (DP of 2-10; at increased concentration of 40 to 60%; P < 0.01) and by 10 - 20 kilodalton (kDa) high molecular weight (HMW) polypeptide and 2-3 kDa low molecular weight polypeptide fractions (at a 50% increase in concentration; P < 0.01). Furthermore, highly purified 10 to 20 kDa HMW polypeptides improved the softness and smoothness and decreased the astringency (at a 25% increase in concentration). This report is the first to provide experimental sensory data indicating that HMW polypeptides improve the mouthfeel of beer. Based on these findings, a new low malt beer was developed that showed significantly higher levels of the 10-20 kDa HMW polypeptides with an overall improved mouthfeel. Mass spectrometric analysis of the 10 to 20 kDa proteins identified several unique foam positive proteins, including barley dimeric alpha-amylase inhibitor-1 and non-specific lipid-transfer protein 1. These 10-20 kDa HMW proteins are likely to be responsible for the improved mouthfeel of beer. © 2020 Kirin Holdings Kabushik Kaisha Co. Ltd. Journal of the Institute of Brewing published by John Wiley & Sons Ltd on behalf of The Institute of Brewing & Distilling

Hematologic Effects Following Crotalinae and Unknown Snake Bites in Northeast Florida

Background: Approximately 5000 snake bites are reported in the United States (US) annually with half of these patients being admitted. Crotalinae species are the most numerous; coral and imported exotic snakes cause a smaller number. Snake venoms are highly stable chemically complex mixtures of proteins. Quantity and composition vary with species and geographic location. Although enzymes contribute to the deleterious effects of the venom, the lethal components may be the smaller low molecular-weight polypeptides. Crotalinae envenomation is known to contain thrombin-like glycoproteins that can induce coagulopathy ranging from asymptomatic lab abnormality to disseminated intravascular coagulopathy (DIC) and life-threatening hemorrhage. In certain geographical areas of the United States thrombocytopenia, hypofibrinogenemia and coagulopathy are common hematological abnormalities, and ones that dictate both a reason for treatment with antivenom as well as an important monitor of therapeutic efficacy. Data on hematological abnormalities following envenomation by crotaline species in Northeast Florida/Southwest Georgia has not been reported before. Methods: We conducted a retrospective review of envenomations that presented to the University of Florida at Jacksonville from April 2013 to October 2018. Patients had to be 16 years or older without any pre-existing hematologic disorder or use of anticoagulant medications. Data including Complete Blood Count, Prothrombin Time (PT), activated Partial Thromboplastin Time (aPTT) and Fibrinogen were measured on presentation, and 4 hours after. Crotaline Fab antivenom (CroFab®) administration was noted if done. Adverse events associated with antivenom therapy, recurrence phenomena, delayed onset of symptoms, and performance of fasciotomy were also recorded. Results: Overall, 119 snakebites were evaluated. The majority were identified as Crotalinae - 25 water moccasin, copperhead or cottonmouth (Agkistrodon piscivorus, Agkistrodon contortrix) bites and 34 rattlesnake (Sistrurus miliarius, Crotalus adamanteus) bites. Male sex dominated the sample with most patients middle-aged (Table 1). More than 80% of patients arrived within 6 hours following the bite. Over 60% of patients received crotaline Fab antivenom. Results are presented in Table 2. Around 12% of patients with water moccasin, copperhead or cottonmouth (Agkistrodon piscivorus, Agkistrodon contortrix) bites had coagulopathy on admission. This compares similarly to data from South Carolina previously showing a 10.89% rate following copperhead bites (Qureshi et al. Blood 2010;116(21):4753). The rate of coagulopathy with rattlesnake bites was however much higher in North Florida at 20.6% - compared to 5.26% in the South Carolina series. Rates of DIC or severe hemorrhage were 8% for water moccasin, copperhead or cottonmouth (Agkistrodon piscivorus, Agkistrodon contortrix) bites and 5.9% for rattlesnake (Sistrurus miliarius, Crotalus adamanteus) bites. When hemostatic defects were looked at separately, the most common abnormality induced was PT/aPTT derangement, followed by hypofibrinogenemia and then thrombocytopenia. This pattern was the same as reported in South Carolina. Recurrence phenomena was observed after 4 hours in a number of patients, however the significance of this remains uncertain as most of these patients remained clinically stable without worsening symptoms. Anaphylactic reaction to the antivenom developed in one patient. Conclusions: In this sample from North Florida, deranged PT/aPTT was the most common hematologic abnormality following envenomation, followed by hypofibrinogenemia and a low rate of thrombocytopenia. Similarities with data from South Carolina were noted, although rattlesnake bites had 4 times higher incidence of coagulopathy in North Florida. DIC or severe hemorrhage was a notable toxicity, affecting 6-8% of Crotalinae cases. Hematologic effects of envenomation do seem to vary by geographic areas in the United States and physicians would benefit from local data to better manage these patients. Disclosures No relevant conflicts of interest to declare.

Вплив зaсолення нa склaд білків і вміст проліну в оргaнaх рослин &lt;i&gt;Salix viminalis&lt;/i&gt; L.

The salinization effect on protein accumulation and proline content in organs of Salix viminalis L. plants was investigated. The plants had been growing in pots with Stebnyk’s tailing soil (during 30 days). The soil of tailing with renewed biocenosis was used like control, for experiment we used soil with spreading of hlikohalophytes. Under saline stress the accumulation of proteins in stems and roots of S. viminalis plants was noticed. This may indicate a plant adaptation to stress. Only low molecular weight polypeptides, in particular proteins with Mr 30, 23, 22, 20, 17, 15, 12, 10 and 8 kD, were found in the electropherograms of all analyzed organs of S. viminalis plants (leaves, stems, roots). Their content significantly varied depending on the organ of the plant. The spectrums of low molecular weight proteins in organs of S. viminalis plants had qualitative and quantitative differences under normal and stress conditions, especially changes of proteins in experimental organs were more expressive. Low molecular weight proteins with Mr 19—21 kD were found in the roots of S. viminalis plants, both in the control and in the experimental variants, but their quantity was higher under salinity stress. An increased content of 22 kD proteins were detected in the stems of the plant, compared to the control. Also, 17 kD Mr proteins were found in the stems during stress, unlike under normal conditions. Less proteins with a molecular weight of 20—23 kD were synthesized in the plants compared to the control. However, we have found an increased content of Mr 10 kD protein in experimental leaves. The accumulation of proline due to salinity in the shoots and roots of S. viminalis plants was established, compared with the control. This can be explained by the water stress that occurs during salinization. Thus, due to the effect of salt stress in the organs of S. viminalis plants, the accumulation of low molecular weight stress proteins and proline was observed, which may indicate certain peculiarities of plant adaptation to salinity conditions.

The Effect of the Food Matrix on the In Vitro Bio-Accessibility and IgE Reactivity of Peanut Allergens.

Factors such as food processing, the food matrix, and antacid medication may affect the bio-accessibility of proteins in the gastrointestinal tract and hence their allergenic activity. However, at present they are poorly understood. Roasted peanut flour was incorporated into either a chocolate dessert or cookie matrix and bio-accessibility were assessed using an in vitro digestion system comprising a model chew and simulated gastric and duodenal digestion. Protein digestion was monitored by SDS-PAGE and immunoreactivity analyzed by immunoblotting and immunoassay. IgE reactivity was assessed by immunoassay using serum panels from peanut-allergic subjects. Roasted peanut flour proteins proved highly digestible following gastro-duodenal digestion even when incurred into a food matrix, with only low molecular weight polypeptides of Mr < 8kDa remaining. When gastric digestion was performed at pH 6.5 (simulating the effect of antacid medication), peanut proteins are not digested; subsequent duodenal digestion is also limited. IgE reactivity of the major peanut allergens Ara h 1, Ara h 2, and Ara h 6, although reduced, was retained after oral-gastro-duodenal digestion irrespective of digestion conditions employed. Peanut allergen bio-accessibility is unaffected by the dessert or cookie matrices whilst high intra-gastric pH conditions render allergens more resistant to digestion.

Extraction, characterization and molecular structure of bovine skin gelatin extracted with plant enzymes bromelain and zingibain.

Bovine skin was incubated with plant enzymes bromelain (B) and zingibain (Z) at the level of 0, 5, 10, 15, 20 and 25 unit/g of skin and gelatin was extracted at 60°C for 6h. Control gelatin was extracted without enzymatic pretreatment. The yield and gel strength were 17.90% and 283.35g for the control samples and 22.26% and 160.88g for B20 samples. The zingibain extracted gelatin (GEZ) samples failed to form gel. Viscosities of GEZ gelatins were significantly (P < 0.05) lower than the gelatins extracted using bromelain (GEB). β and α chains were absolutely degraded in all GEB and GEZ samples. Only smear bands were observed in GEZ gelatins whereas GEB samples revealed presence of low molecular weight polypeptides. Loss of molecular order was noticed in Z5 as elaborated by Fourier transform infrared (FTIR) spectroscopy. Larger particle size, denser and inter-connected irregular network was observed in B20 under scanning electron microscopy. Based on the results obtained, bromelain, particularly at level 20, could be used to obtain a better quality gelatin with higher yield compared to zingibain.

Expression of plasmolemma proteins of the absorptive enterocytes of the cattle in the late fetal period

The article presents new scientific data on the expression of plasmalemma proteins of the absorptive enterocytes of the bovine intestines of five to nine months of age. In the late fetal period, 31 and 27 protein fractions of apical and basolateral membranes, respectively, were found in the plasmalemma of the jejunum intestine, which had a molecular weight of 9.6 kDa to 300 kDa. Twenty-nine protein fractions were detected in the apical membranes of five-month-old cattle enterocytes. It should be noted that protein fractions with low molecular weight (up to 24 kDa) were only 19.7 %, with molecular weights from 24 kDa to 100 kDa – 69.2 %, and fractions with molecular weights of 100 kDa and more were detected only – 11.1 % of the total number of polypeptides. Twenty-five protein fractions with a molecular weight of 9.6 to 155 kDa were found in the basolateral enterocyte membranes of five-month-old fetus. A large proportion of the detected protein fractions belonged to low molecular weight polypeptides (9.6–24 kDa – 40.26 %). Proteins with a molecular weight of 24–95 kDa – 55.2 %, with a molecular mass of 100 kDa and more were found only 4.56 %. High molecular weight proteins in the basolateral membrane of jejunum enterocytes of five-months-old cattle with a molecular weight greater than 155 kDa were not detected by electrophoresis (unlike the apical membrane). Analysis of the results of studies membranes protein of cattle enterocytes in late fetal period indicates significant changes in their polypeptide composition. In particular, in the basolateral membranes of enterocytes during the late fetal period there is a decrease in the content of low molecular weight protein fractions (3.3 times; P ≤ 0.001) and an increase in the proportion of high molecular weight. In addition, from the age of eight months, proteins with a molecular weight of 9.6–14.2 kDa and 75 kDa disappear in the basolateral membrane. Instead, proteins with a molecular weight of 300 kDa and 170-1885 kDa are appeared. In addition, in the apical membranes of enterocytes there is a significant decrease in the content of low molecular weight protein fractions and an increase in polypeptides with a molecular weight greater than 100 kDa. The appearance in the apical membranes of jejunum enterocytes of calves from eight months of age embryonic development of fractions of polypeptides with molecular weight of 24 kDa and 66 kDa, which are present until the end of the fetal period.

Interest of Beta-2-Microglobilin Plasma Assay in Iterative Haemodialysis in the Nephrology and Haemodialysis Department of University Teaching Hospital of Point G, Bamako, Mali

Beta-2-microglobulin (B2M) is a low molecular weight polypeptide (11,800 Da) that exists in a free form and a form bound to cell membranes (light chains of HLA class I molecules). Their dosage is used in the exploration and monitoring of renal function in haemodialysis patients, hence the interest of this study, the objective of which is to study the different players involved in the increase of beta-2-microglobulin. Materials and Methods: This was a prospective and descriptive study from January 1st, 2017 to August 31, 2017 (08 months). All patients with chronic hemodialysis for 3 years or more were included. We analyzed sociodemographic, clinical and paraclinical data. Results: We collected 50 patients. The mean age was 50 ± 4.6 years with extremes of 30 and 82 years. The female sex predominated (52%). Chronic end-stage renal failure was hypertensive (86%), diabetic (4%). All patients benefited from intermittent hemodialysis for 8 hours per week using a low permeability membrane (cuprophane). The average duration of hemodialysis was 68 ± 6.4 months with extremes of 36 and 204 months. Twenty percent (20%) and four percent (4%) of chronic dialysis patients had joint pain and sensory deficit. Phalen’s sign was positive in 2% (1 case), Tinel’s sign in 2% (1 case) and carpal tunnel syndrome in 2% (1 case). The mean serum beta-2-microglobulin level was 58.34 ng/l with extremes of 16.99 and 112.24 ng/l. There was a correlation between hypertensive nephropathies and beta-2-microglobulin levels above 50 ng/l (P < 0.001). The mortality rate was 6%. Conclusion: Our study has objectified factors such as inadequate dialysis (8 hours/week), use of low permeability membrane in the increase of beta-2-microglobulin. The increase in serum beta-2-microglobulin levels in our patients is evidence of poor purification of medium molecules. Its reduction can be established by improving the quality of dialysis, in particular by using a high-permeability membrane.

Effects of molecular weight and structural conformation of multivalent-based elastin-like polypeptides on tumor accumulation and tissue biodistribution.

In order to improve clinical outcomes for novel drug delivery systems, distinct optimization of size, shape, multifunctionality, and site-specificity are of utmost importance. In this study, we designed various multivalent elastin-like polypeptide (ELP)-based tumor-targeting polymers in which multiple copies of IL-4 receptor (IL-4R)-targeting ligand (AP1 peptide) were periodically incorporated into the ELP polymer backbone to enhance the affinity and avidity towards tumor cells expressing high levels of IL-4R. Several ELPs with different molecular sizes and structures ranging from unimer to micelle-forming polymers were evaluated for their tumor accumulation as well as in vivo bio-distribution patterns. Different percentages of cell binding and uptake were detected corresponding to polymer size, number of targeting peptides, or unimer versus micelle structure. As compared to low molecular weight polypeptides, high molecular weight AP1-ELP showed superior binding activity with faster entry and efficient processing in the IL-4R-dependent endocytic pathway. In addition, in vivo studies revealed that the high molecular weight micelle-forming AP1-ELPs (A86 and A100) displayed better tumor penetration and extensive retention in tumor tissue along with reduced non-specific accumulation in vital organs, when compared to low molecular weight non-micelle forming AP1-ELPs. It is suggested that the superior binding activities shown by A86 and A100 may depend on the multiple presentation of ligands upon transition to a micelle-like structure rather than a larger molecular weight. Thus, this study has significance in elucidating the different patterns underlying unimer and micelle-forming ELP-mediated tumor targeting as well as the in vivo biodistribution.

Recombinant buckwheat trypsin inhibitor decreases fat accumulation via the IIS pathway in Caenorhabditis elegans.

Buckwheat trypsin inhibitor (BTI) is a low molecular weight polypeptide that can help to prevent metabolic diseases such as obesity, hyperglycemia and hyperlipidemia. Herein, the effects of recombinant BTI (rBTI) on fat accumulation in Caenorhabditis elegans were studied. rBTI prevented fat accumulation under normal and high glucose conditions, and led to significantly shorter body widths without affecting C. elegans feeding behavior. Results also indicate that rBTI altered fat breakdown, synthesis, and accumulation by altering the transcription, expression and activity of key enzymes in lipolysis and fat synthesis. In daf-2 and daf-16 mutants, rBTI did not prevent fat accumulation, indicating that rBTI activity relies on the insulin/insulin-like growth factor (IIS) pathway. Overall rBTI may regulate changes in lipolysis and fat synthesis by down-regulating the IIS pathway, which can affect fat accumulation. These findings support the application of rBTI in preventing obesity, hyperglycemia and hyperlipemia.

Host-pathogen interactions upon the first and subsequent infection of Galleria mellonella with Candida albicans

Insects are able to develop enhanced resistance in response to repeated infection. This phenomenon is called immune priming. In this work, so-called “primed” Galleria mellonella larvae were re-infected with a lethal dose of Candida albicans 48 h after injection of a non-lethal dose, while “non-primed” larvae were infected only with a lethal dose. The increased resistance of the primed larvae correlated with a slower rate of body colonisation by the fungus. Changes in the protein profiles were detected in the whole hemolymph of the primed insects. The analysis of low-molecular weight proteins and peptides obtained with the use of three different organic solvents and comparative quantitative HPLC analysis thereof showed that the primed larvae did not have higher amounts of any infection-inducible polypeptides than the non-primed larvae. Moreover, electrophoresis of low-molecular weight polypeptides revealed an even lower level of immune-induced peptides in the primed larvae than in the non-primed ones.Furthermore, the defence activity of larval hemolymph, i.e. the antifungal, antibacterial, and lysozyme-type activity, was up-regulated in the primed larvae at the time of re-infection and, consequently, at the early time points after the infection with the lethal dose. Twenty four hours after the infection, these parameters were equally high in the non-primed and primed larvae. Accordingly, at the time of the injection of the lethal dose, certain immune-inducible genes were up-regulated. However, 24 h after the infection with the lethal dose, their expression in both groups was incomparably higher than at the time of the infection and, in most cases, it was as high in the primed larvae as in the non-primed ones. We found that only anti yeast-like activity was enhanced 24 h after the re-infection. This correlated with results obtained by testing the priming effect in heterologous systems: the primed animals did not exhibit higher resistance to the other pathogens tested.