Low Molecular Weight Protein Fraction Research Articles

The effect of probiotic strains on the proteolytic activity and peptide profiles of lupin oat-based yoghurt

Plant-based yoghurt is on the rise, addressing both sustainability and innovation in food production. The macro-molecular changes driven by bacterial strains during fermentation of plant-based yoghurt leading to diverse nutritional functionality, however, is overlooked. Here, the lupin-oat milk yoghurt was developed using three distinctive commercial starter cultures composed of Lactobacillus delbrueckii sub bulgaricus, Streptococcus thermophilus and Lactobacillus rhamnosus for yoghurt 1 (Y1), Lactobacillus delbrueckii sub bulgaricus, Streptococcus thermophilus and Lactobacillus paracasei for yoghurt 2 (Y2), Lactobacillus plantarum and Bifidobacterium sps for yoghurt 3 (Y3). The post-acidification, proteolytic activity, amino acid composition, cell viability, peptide profile and angiotensin-converting enzyme (ACE) inhibitory activity were investigated during seven days of refrigeration at 4 °C. Gel electrophoresis and size exclusion chromatography (SEC) of yoghurts, showed substantial degradation of proteins into low molecular weight protein fractions (45, 55 and 75 kDa) which are complemented by an increase in small polypeptides with a molecular weight of <20 kDa. The bacteria did not fully utilize the released peptides, leading to significant accumulations in the medium. This observation indicates the potential presence of bioactive compounds with beneficial effects. The SEC peak fraction containing a smaller peptide size ranging from 0.059 to 0.87 kDa showed better ACE inhibitory activity. A comprehensive analysis of peptide profiling of the yoghurts was done using Nano UPLC-MS/MS which showed co-cultures promoted the formation of peptides. After undergoing bacterial fermentation, the number and types of peptides followed the Y3>Y1>Y2 sequence. This study emphasizes the potential of lupin-oat yoghurts peptides as a functional component.

Novel Antimicrobial Peptide from the Hepatopancreas of the Red King Crab.

Crustaceans have successfully adapted to survive in their natural habitat, rich in microorganisms, due to the presence of antimicrobial peptides (AMPs) in their organism. They achieve this adaptation despite lacking the highly specific adaptive immune system found in vertebrates. One valuable source of AMPs is the hepatopancreas, a waste product from crab fishery and its processing. Applying zymographic and spectrophotometric techniques, we discovered a small peptide (approximately 5 kDa) within a low molecular weight protein fraction extracted from the acetone powder of the red king crab hepatopancreas. This peptide hydrolyzes both M. lysodeikticus cell wall and M. lysodeikticus cell wall polysaccharide, while showing no activity against gelatin. The found peptide may be of interest for application in medicine, biotechnology, and the food industry, for example as a bio-preservative.

Chenopodium quinoa's Ingredients Improve Control of the Hepatic Lipid Disturbances Derived from a High-Fat Diet.

This study explored the effects of Chenopodium quinoa's ingredients on the major lipids' hepatic profile and the functional selective differentiation of monocyte-derived macrophages and innate lymphoid cells in mice on a high-fat diet. Six-week-old Rag2-/- and Rag2-/-Il2-/- mice received (12 days) a low-molecular-weight protein fraction (LWPF) or the lipid fraction (qLF) obtained from the cold pressing of C. quinoa's germen. At the end of the experiment, mouse serum and liver tissue were collected. The differences in triglycerides, phospholipids, and the major lipids profile were analyzed. Infiltrated monocyte-derived macrophages and innate lymphoid cells (ILCs) and the expression of liver metabolic stress-related mRNA were measured. In the Rag2-/- mice, feeding them LWPF appeared to improve, to a larger extent, their hepatic capacity to utilize fatty acids in comparison to the qLF by preventing the overwhelming of triglycerides (TGs), despite both reducing the hepatic lipid accumulation. An analysis of the hepatic major lipids profile revealed significant increased variations in the PUFAs and phospholipid composition in the Rag2-/- mice fed with the LWPF or LF. The Rag2-/-Il2-/- mice, lacking innate and adaptive lymphocytes, seemed resistant to mobilizing hepatic TGs and unresponsive to lipid accumulation when fed with the LF. Notably, only the Rag2-/- mice fed with the LWPF showed an increased proportion of hepatic CD68+F4/80+ cells population, with a better controlled expression of the innate immune 'Toll-like' receptor (TLR)-4. These changes were associated with an oriented expansion of pluripotential CD117+ cells towards ILC2s (CD117+KLRG1+). Thus, C. quinoa's ingredients resulted in being advantageous for improving the mechanisms for controlling the hepatic lipotoxicity derived from a high-fat diet, promoting liver macrophage and ILCs expansion to a selective functional differentiation for the control of HFD-driven immune and metabolic disturbances.

Impact of vacuum freeze-drying on the reconstituted camel milk composition

In the dairy technology, for the preserving of initial nutritional properties of whole milk commonly a vacuum freeze-drying approach is used. However, a significant impact on the quality indicators of the resulting products within vacuum freeze-drying has a temperature of the product sublimation in the freeze-drying chamber. From the point of view of energy savings and maximum preservation of the initial qualities, the optimal sublimation temperature value is recommended at the t = -15 °C within vacuum freeze-drying process. The physicochemical indicators of whole and reconstituted camel milk have similar values within acceptable limits. Nevertheless, partial denaturation of amino acids that leading to the decreasing in the content of low molecular weight protein fractions and for the increasing of protein fractions with higher molecular weight are occurred. Thermolabile whey protein compounds, such as Albumin and Globulin fractions are especially susceptible to denaturation changes, due to the hydration membrane of proteins present on the surface is destroyed, leading to minor changes in the amino acid composition.

Surface-Enhanced Raman Spectroscopic (SERS) Characterization of Low Molecular Weight Fraction of the Serum of Breast Cancer Patients with Principal Component Analysis (PCA) and Partial Least Square-Discriminant Analysis (PLS-DA)

Vibrational spectroscopic techniques including Raman spectroscopy have been increasingly used for the analysis of body fluids particularly blood serum. Low molecular weight protein fractions (LMWFs) present in blood serum are usually associated with pathological condition related to disease. However, human serum analysis is challenging because these LMWFs are dominated by high molecular weight proteins, making analysis by Raman spectroscopy difficult. In the current study, in order to overcome this limitation, the separation of the high molecular weight fraction (HMWF) was done by centrifugal filtration of the sera from breast cancer patients using 50 kDa filters. The filtrate was analyzed by surface-enhanced Raman spectroscopy (SERS). Comparison of the SERS spectral features of the whole serum and their filtrate fraction obtained by ultra-centrifugation indicate that this approach is capable of potentially targeting small circulating biomarkers dominated by the HMWF in unmodified serum. SERS spectra of the filtrate fractions of modified disease samples contain prominent peaks at 477, 684, 743, 859, 1263, 1275 and 1512 cm−1 in comparison to unmodified serum. The SERS peaks at 573, 594, 730, 743, 859, 963, 1103 and 1453 cm−1 in spectra collected from cancerous serum filtrate fractions distinguished them from healthy samples. The spectra were further analyzed by principal component analysis (PCA) and partial least squares – discriminant analysis (PLS-DA). The validated PLS-DA model yielded classification of the cancerous and healthy samples with the sensitivity and specificity of 99% each.

Comparative study of technologies for extraction of biologically active substances from the raw material of animal origin

Technologies of isolation and concentration of biologically active substances, developed in the middle of the 20th century, need adjustment and adaptation to modern conditions both to increase the activity of substances and for greater economic efficiency. The aim of the research is the comparison of dynamics of biologically active compounds extraction from porcines pancreas in two methods: the saline method based on 0.9% sodium chloride solution, and the acidic method based on 2.4% trichloroacetic acid solution. Also the purpose of research is to assess the possibilities for further optimization of technologies. The total protein concentration based on the biuret reaction in the samples taken during the extraction, as well as the calculation and analysis of the point degrees and rates of extraction are chosen as the controlled parameters. Local maxima of the protein yields into the extractant media at the 60th, 135th and 255th minute were recorded during saline extraction; and at the 75th and 135th minute during acid extraction. Also the proteomic profile of the extracts was studied. Wide range of compounds with molecular weight of less than 52 kDa was found in extracts based on physiological saline solution, and protein substances of whole presented range of molecular weights in trichloroacetic acid based extracts were considered. The predominance of low molecular weight protein fraction of interest was noted also in this method of extraction in comparison with the other methods of extraction. According to the UniProt database, we assume availability of probable compounds with a molecular weight of less than 30 kDa in the purified acidic extract. The presence of some proteins absent in the final saline extract was noted. The acidic erythrograms showed a weak degrading effect of both types of extracts on the membranes of rat erythrocytes, as well as the cytoprotective effect of acidic ultrafiltrates (less than 3 kDa). The obtained results prove a better efficiency of trichloroacetic acid extraction method used for obtaining a mixture of a wide range of compounds, including biologically active substances of low molecular weight.

Is Lignocaine Preconditioning Effective to Treat Severe Pulmonary Vasoconstriction Induced by Protamine During Cardiac Surgery

Protamine is a low molecular weight protein fraction (5.5-13.0 kDa) that is rich in basic arginine (67%) and lysine amino acids. They are basic polypeptides that neutralize the strongly negatively charged heparin. This study was aimed to explore the effect of lignocaine preconditioning on protamine-induced pulmonary vasoconstriction, which is used to reverse the effect of heparin during cardiac surgery. This was a prospective, single-centre, double-blind and randomised study performed among eighty paediatric patients of either sex in the age group between 1 to 12 years with acyanotic congenital heart disease, scheduled for elective on-pump cardiac surgery under general anaesthesia. The study participants were divided into four groups: Group A non-pulmonary hypertension+lignocaine preconditioning, group B- non-pulmonary hypertension+normal saline preconditioning, group C-pulmonary hypertension+lignocaine preconditioning and group D-pulmonary hypertension +normal saline preconditioning. Haemodynamic parametres, pulmonary inflammatory compounds, and pulmonary function were assessed intraoperatively at 6, 2, and 3-time points, respectively. Routine perioperative data were collected and analysed. Shapiro-Wilk test was used to test if the data were normally distributed. Continuous variables are expressed as mean ± standard deviation (SD) and compared across groups using one-way Analysis of Variance (ANOVA). Categorical variables were expressed as the number of patients together with the corresponding percentage of the total group and analyzed using chi-square tests or Fisher’s Exact test. Spearman’s correlation analysis was performed to evaluate the relationship between pulmonary haemodynamic indicators and inflammatory factors. A P-value<0.05 was considered statistically significant. Group B exhibited increased pulmonary artery pressure (PAP), Mean airway pressure (Paw), Respiratory index (RI), and alveolar-arterial oxygen difference (A-aDO ). Group D exhibited increased Paw, RI, and A-aDO and decreased dynamic pulmonary compliance (Cydn) and oxygen index (OI) after protamine administration. These changes were not observed in groups A and C. Compared with groups A and C groups, plasma thromboxane B2 (TXB2) level in groups B and D were higher, but 6-keto-prostaglandin F1a (6-keto-PGF1a) in groups B and D groups was lower. The incidence of protamine adverse reactions in groups A and C were lower than that in B and D groups respectively. The precondition of lignocaine before neutralization of heparin effectively reverses protamine-induced pulmonary vasoconstriction during cardiac surgery.

Green Synthesis of Copper Oxide Nanoparticles Using Protein Fractions from an Aqueous Extract of Brown Algae Macrocystis pyrifera

Amongst different living organisms studied as potential candidates for the green synthesis of copper nanoparticles, algal biomass is presented as a novel and easy-to-handle method. However, the role of specific biomolecules and their contribution as reductant and capping agents has not yet been described. This contribution reports a green synthesis method to obtain copper oxide nanoparticles (CuO-NPs) using separated protein fractions from an aqueous extract of brown algae Macrocystis pyrifera through size exclusion chromatography (HPLC-SEC). Proteins were detected by a UV/VIS diode array, time-based fraction collection was carried out, and each collected fraction was used to evaluate the synthesis of CuO-NPs. The characterization of CuO-NPs was evaluated by Dynamic Light Scattering (DLS), Z-potential, Fourier Transform Infrared (FTIR), Transmission Electron Microscope (TEM) equipped with Energy Dispersive X-ray Spectroscopy (EDS) detector. Low Molecular Weight (LMW) and High Molecular Weight (HMW) protein fractions were able to synthesize spherical CuO-NPs. TEM images showed that the metallic core present in the observed samples ranged from 2 to 50 nm in diameter, with spherical nanostructures present in all containing protein samples. FTIR measurements showed functional groups from proteins having a pivotal role in the reduction and stabilization of the nanoparticles. The highly negative zeta potential average values from obtained nanoparticles suggest high stability, expanding the range of possible applications. This facile and novel protein-assisted method for the green synthesis of CuO-NPs may also provide a suitable tool to synthesize other nanoparticles that have different application areas.

The Activation of Prothrombin Seems to Play an Earlier Role than the Complement System in the Progression of Colorectal Cancer: A Mass Spectrometry Evaluation.

Colorectal cancer (CRC) is the second cause of death in men and the third in women. This work deals with the study of the low molecular weight protein fraction of sera from patients who underwent surgery for CRC and who were followed for several years thereafter. MALDI-TOF MS was used to identify serum peptidome profiles of healthy controls, non-metastatic CRC patients and metastatic CRC patients. A multiple regression model was applied to signals preliminarily selected by SAM analysis to take into account the age and gender differences between the groups. We found that, while a signal m/z 2021.08, corresponding to the C3f fragment of the complement system, appears significantly increased only in serum from metastatic CRC patients, a m/z 1561.72 signal, identified as a prothrombin fragment, has a significantly increased abundance in serum from non-metastatic patients as well. The findings were also validated by a bootstrap resampling procedure. The present results provide the basis for further studies on large cohorts of patients in order to confirm C3f and prothrombin as potential serum biomarkers. Thus, new and non-invasive tests might be developed to improve the classification of colorectal cancer.

An integrative proteogenomics approach reveals peptides encoded by annotated lincRNA in the mouse kidney inner medulla.

Long noncoding RNAs (lncRNAs) are intracellular transcripts longer than 200 nucleotides and lack protein-coding information. A subclass of lncRNA known as long intergenic noncoding RNAs (lincRNAs) are transcribed from genomic regions that share no overlap with annotated protein-coding genes. Increasing evidence has shown that some annotated lincRNA transcripts do in fact contain open reading frames (ORFs) encoding functional short peptides in the cell. Few robust methods for lincRNA-encoded peptide identification have been reported, and the tissue-specific expression of these peptides has been largely unexplored. Here we propose an integrative workflow for lincRNA-encoded peptide discovery and test it on the mouse kidney inner medulla (IM). In brief, low molecular weight protein fractions were enriched from homogenate of IMs and trypsinized into shorter peptides, which were sequenced by high resolution liquid chromatography-tandem mass spectrometry (LC-MS/MS). To curate a hypothetical lincRNA-encoded peptide database for peptide-spectrum matching following LC-MS/MS, we performed RNA-Seq on IMs, computationally removed reads overlapping with annotated protein-coding genes, and remapped the remaining reads to a database of mouse noncoding transcripts to infer lincRNA expression. Expressed lincRNAs were searched for ORFs by an existing rule-based algorithm, and translated ORFs were used for peptide-spectrum matching. Peptides identified by LC-MS/MS were further evaluated by using several quality control criteria and bioinformatics methods. We discovered three novel lincRNA-encoded peptides, which are conserved in mouse, rat, and human. The workflow can be adapted for discovery of small protein-coding genes in any species or tissue where noncoding transcriptome information is available.

Quality and productivity of hybrid wheat depending on the tillage practices

The aim of this study was to assess the impact of soil tillage systems on technological characteristics, mineral composition and grain yield of selected hybrid wheat cultivars grown in variable climatic conditions. The following factors were studied: tillage systems, namely conventional (CT), reduced (RT) and no tillage (NT) and hybrid cultivars of winter wheat (Hyfi, Hybiza and Hystar). Cvs. Hyfi and Hybiza were characterised by good technological parameters and protein quality, and additionally by a higher Fe and Zn content and a higher grain yield than cv. Hystar. Meteorological conditions (rainfall total 414.9 mm, mean temperature 8.8 °C) during the growing season caused an increase in the yield of grain, protein, gluten and Zeleny test as well as the total gliadins and glutenins. Higher rainfall reduced grain quality and Fe and Zn content, while precipitation deficits reduced grain yield. Quality parameters and grain yield, as well as total gliadins and glutenins in CT and RT were similar, and significantly higher compared with NT. Soil tillage systems did not differentiate mineral composition, except for the higher content of Fe in CT as well as the content of albumins and globulins, α/β, ω gliadins and low molecular weight (LMW) glutenins and protein fraction ratios in grain.

Antibacterial potential of Antimicrobial peptides containing whole proteins of two Adiantum species from Himalaya against selected human bacterial pathogens

Increasing tendency of drug resistance and continuously emerging new diseases have limited the available therapeutic options. Plants are still a positive hope for search of new therapeutic agents, which have provided many effective therapeutic agents and have not been yet explored to their full potential. In the present study, two ferns Adiantum edgeworthii and Adiantum capilllus-veneris from the Himalayas, have been explored for the presence of antimicrobial peptides (AMPs) in them. Antimicrobial peptides are different class of therapeutic agents having multimodal action mechanism and different site of action. Hence they could be a solution against the problem of drug resistance. In the present study, whole proteins (WPs) of the ferns were precipitated using TCA, and low molecular weight protein fractions (LMPFs) of WPs were isolated using SDS-PAGE. Antibacterial activities of WPs and LMPFs were tested against six human pathogenic bacteria S. aureus, S. pneumoniae, E. faecalis, and K. pneumoniae, P. aeruginosa and E. coli. The results showed that AMPs were present both the ferns and antibacterial potency of LMPFs was higher than WPs. It was also observed that WPs of A. capillus-veneris was about 11.4% more active than WPs of A. edgeworthii. Antibacterial activity of WPs was compared with two standard antibiotics (Amoxicillin and Erythromycin) and comparable results were obtained. Further research for purification and characterization of pure antimicrobial peptides from these plants are expected to provide new therapeutic agents.

Modifications of the Protein Characteristics of Pacaya Caused by Thermal Treatment: A Spectroscopic, Electrophoretic and Morphological Study.

The inflorescences of Chamaedorea tepejilote Liebm. are consumed as food in Central America and southern Mexico but is an underutilized food because of its sensory characteristics, principally due to its bitter taste. However, the inflorescences of Chamaedorea tepejilote Liebm. are nutritionally promising due to their high protein content (approximately 25%). Protein isolates from pacaya were modified via three different thermal treatments to determine the effect of the treatments on the protein structures. Scanning electron microscopy indicated that the pacaya protein isolate particles had less rough and irregular surfaces with larger particle sizes due to an aggregation process when a thermal treatment was used compared to those when no thermal treatment was used. An increase in the intensity of the low molecular weight protein fractions (≤20 kDa) in the electrophoretic pattern of the proteins was observed, which was generated by the hydrolysis of the proteins by heat treatment. The modifications in the FT-IR spectra showed that thermal treatment of pacaya affected the secondary structure of its proteins, mainly when microwave treatment was used. Raman spectroscopy revealed that the α–helical structure was dominant in the proteins of pacaya and that thermal treatment increased the fraction of the β–sheet structure at the expense of the α–helical structure.

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.

Structural proteins of plasmolemma of the jejunum absorbing enterocytes of cattle fetus in early fetal period

The data on the concentration of structural proteins of plasmolemma of the absorption enterocytes of the cattle fetus in the early fetal period are presented. Changes in the protein composition of the apical and basolateral membranes of enterocytes are manifested, characterized not only by changes in their ratio within different cell domains, but also by the dynamic redistribution of the number of different fractions of polypeptides between the poles of these cells. Analysis of the results of electrophoresis of apical membranes of the cattle fetus enterocytes in the early fetal period indicates a decrease in the content of low molecular weight protein fractions and an increase in high molecular weight. In the apical membranes of enterocytes of two-month-old cattle fetus, 25 protein fractions with a molecular weight of 9.6 to 205 kDa were detected. In the basolateral membranes revealed 23 protein fractions with a molecular weight of 9.6 to 120 kDa. High molecular weight fractions of polypeptides with molecular weights of 250 kDa and 300 kDa appear from the age of three months of embryos of calves. In the basolateral membranes of enterocytes, there is a slight decrease in the content of low molecular weight protein fractions, and from the four months of age of cattle fetus, high molecular weight fractions of polypeptides with molecular weights of 22.5 kDa and 155 kDa appear, which are absent in basolateral membranes of enterocytes. Two-month-old fetus lack proteins with a molecular weight of 19 kDa, 24 kDa, and 66 kDa in the apical part, whereas proteins with a mass of 22.5 kDa, 155 kDa, 170–185 kDa, and 205 kDa are absent on the basolateral membrane. In the apical membrane of enterocytes significantly more proteins with a low molecular weight of 9.6-14.2 kDa (1.56 times; P ≤ 0.001), whereas in the basolateral membrane a significantly higher concentration of proteins with a molecular weight of 15.5 kDa (2.06 times; P ≤ 0.001) and 17 kDa (3.62 times; P ≤ 0.001).

Structural proteins of plasmolemma of the jejunum absorbing enterocytes of cattle fetus in early fetal period

The data on the concentration of structural proteins of plasmolemma of the absorption enterocytes of the cattle fetus in the early fetal period are presented. Changes in the protein composition of the apical and basolateral membranes of enterocytes are manifested, characterized not only by changes in their ratio within different cell domains, but also by the dynamic redistribution of the number of different fractions of polypeptides between the poles of these cells. Analysis of the results of electrophoresis of apical membranes of the cattle fetus enterocytes in the early fetal period indicates a decrease in the content of low molecular weight protein fractions and an increase in high molecular weight. In the apical membranes of enterocytes of two-month-old cattle fetus, 25 protein fractions with a molecular weight of 9.6 to 205 kDa were detected. In the basolateral membranes revealed 23 protein fractions with a molecular weight of 9.6 to 120 kDa. High molecular weight fractions of polypeptides with molecular weights of 250 kDa and 300 kDa appear from the age of three months of embryos of calves. In the basolateral membranes of enterocytes, there is a slight decrease in the content of low molecular weight protein fractions, and from the four months of age of cattle fetus, high molecular weight fractions of polypeptides with molecular weights of 22.5 kDa and 155 kDa appear, which are absent in basolateral membranes of enterocytes. Two-month-old fetus lack proteins with a molecular weight of 19 kDa, 24 kDa, and 66 kDa in the apical part, whereas proteins with a mass of 22.5 kDa, 155 kDa, 170–185 kDa, and 205 kDa are absent on the basolateral membrane. In the apical membrane of enterocytes significantly more proteins with a low molecular weight of 9.6-14.2 kDa (1.56 times; P ≤ 0.001), whereas in the basolateral membrane a significantly higher concentration of proteins with a molecular weight of 15.5 kDa (2.06 times; P ≤ 0.001) and 17 kDa (3.62 times; P ≤ 0.001).

Protein Corona over Mesoporous Silica Nanoparticles: Influence of the Pore Diameter on Competitive Adsorption and Application to Prostate Cancer Diagnostics.

Diagnostic tests based on proteomics analysis can have significant advantages over more traditional biochemical tests. However, low molecular weight (MW) protein biomarkers are difficult to identify by standard mass spectrometric analysis, as they are usually present at low concentrations and are masked by more abundant resident proteins. We have previously shown that mesoporous silica nanoparticles are able to capture a predominantly low MW protein fraction from the serum, as compared to the protein corona (PC) adsorbed onto dense silica nanoparticles. In this study, we begin by further investigating this effect using liquid chromatography–mass spectrometry (LC–MS)/MS and thermogravimetric analysis (TGA) to compare the MW of the proteins in the coronas of mesoporous silica nanoparticles with the same particle size but different pore diameters. Next, we examine the process by which two proteins, one small and one large, adsorb onto these mesoporous silica nanoparticles to establish a theory of why the corona becomes enriched in low MW proteins. Finally, we use this information to develop a novel system for the diagnosis of prostate cancer. An elastic net statistical model was applied to LC–MS/MS protein coronas from the serum of 22 cancer patients, identifying proteins specific to each patient group. These studies help to explain why low MW proteins predominate in the coronas of mesoporous silica nanoparticles, and they illustrate the ability of this information to supplement more traditional diagnostic tests.

Study of the National Cooked Smoked Meat Products While Tests with Laboratory Animals at the Pathology Models with the Purpose to Confirm the set of Biocorrective Features

Conducted physico-chemical and biological studies of Goji berries and national products made it possible to obtain information on the bioavailability of nutrients included in the product, to evaluate their food value and nutritional value, and their functional orientation. The study of the processes of digestibility and absorption of the developed products on the gastric invitro model and the monolayer of the intestinal wall epithelium showed high absorption and assimilability of the low molecular weight (from 30 kDa and below) protein fraction of the studied product. The detected acceleration of the absorption of nutrients of the tested products was reflected positively on the dynamics of changes in the biochemical composition of the blood, which, in turn, will lead to an acceleration of the biocorrecting action of functional biologically active substances. As a result of the experiment it was established that Goji berries, characterized by high catalase activity, have a prominent antioxidant effect, helping to control free radical oxidation in the rat organism with hyperlipidemia by decrease of MDA concentration (to 30%) and improvement of blood serum antioxidant activity (to 40 %). A prominent hipolipidemic (lipid-lowering) effect of berries has been established, which consists in normalization of the blood serum lipid profile of rats with hyperlipidemia 28 days after the beginning of feeding (decrease in total cholesterol (by 1.5 times), low density lipoproteins (to 40%) and blood serum atherogenity index (by more than 50%) with increase of high-density lipoproteins (up to 45%).

Protein Adsorption From Biofluids on Silica Nanoparticles: Corona Analysis as a Function of Particle Diameter and Porosity.

A study on the adsorption of proteins from fetal bovine serum (FBS) on spherical dense and mesoporous silica nanoparticles with a wide range of diameters, from 70 to 900 nm, is presented. Monodisperse populations of particles with a range of diameters were obtained through modifications of the Stöber method. Extensive characterization of the particles was then performed using N2 physisorption, TEM, DLS, and ζ-potential. Following serum exposure, proteomic evaluation in concert with thermogravimetric analysis revealed the associated concentrations of each protein identified in the hard corona. Small particles adsorbed the largest amount of protein, due to their larger external surface area. Proteins with low molecular weights (<50 kDa) constituted the majority of the protein corona, totaling between 60 and 80% of the total mass of adsorbed protein. Here, the higher surface curvature of small particles favors the enrichment of smaller proteins. Porosity does not promote protein adsorption but improves deposition of the low molecular weight protein fraction due to the size-exclusion effect related to pore diameter. These results have important implications for the use of dense and porous silica nanoparticles in biomedical applications.

The effect of bacterial contamination on friction and wear in metal/polyethylene bearings for total joint repair—A case report

During preclinical wear evaluation of joint replacement components bacterial contamination is a concern. However, there are no standardized procedures to retard microbial growth and little is known about the potential effects on friction and wear. Recently, the fraction of low-molecular weight proteins has been shown to decrease in the presence of bacteria and it is well established that the lubricant proteins play an important role in the wear of polyethylene components. In this case report we show that the presence of bacterial and fungal contamination can alter polyethylene friction and wear. Ultra-high molecular weight polyethylene pins were tested in a pin-on-flat tribometer using two bovine serum lubricants, A and B, identical, except that lubricant B contained a bactericide and fungicide (gentamicin and Fungizone®, respectively). Each test consisted of consecutive 250,000 cycle runs after which the pins were cleaned and weighed and fresh lubricant was used for the next run. Wear was determined gravimetrically and chemically via a tracer substance. The presence of the anti-microbial agents stabilized the friction coefficient around 0.06, which otherwise increased to values above 0.1 after an incubation period of 150,000 cycles. The bactericide also led to a significant reduction in the polyethylene wear rate, and wear factors obtained with lubricant B were six-fold lower than those in lubricant A. The results of this case study suggest the possibility that microbial contamination should be considered as a potential factor in evaluating the wear rate of polyethylene. Reproducible polyethylene wear testing may therefore entail proper bactericidal and fungicidal protocols. These results also suggest that the effects of joint infections on the wear of prosthetic bearing surfaces and concomitant clinical implications bear investigation.