Peptide Bands Research Articles

Functional characterization of enzyme-hydrolysed soy and whey protein isolates: A comparative approach

In the present study, the soy protein and whey protein isolates were hydrolysed using food-grade endoenzymes (papain and pancreatin) for different time periods (10, 30, 60, 90, and 120 min) at 35 °C. Several functional properties were examined at various times of hydrolysis. Papain hydrolysed both the isolates better than pancreatin throughout the hydrolysis period. The degree of hydrolysis of papain hydrolysed soy protein isolate was 1.12 after 120 min of hydrolysis. During the hydrolysis, the particle size of the isolates was decreased initially followed by slight increase. The particle size of whey protein isolate was higher than the soy protein isolate. Zeta potential was decreased during hydrolysis for both isolates. The particle size and zeta potential were inversely proportional to the degree of hydrolysis. SDS-PAGE has shown that, soy protein isolate had a greater number of peptide bands after hydrolysis than whey protein isolate. Emulsifying activity increased with hydrolysis time. Emulsion stability increased after enzyme addition and decreased with time. From this study it was evident that, enzymatic hydrolysis of defatted soy protein isolate enhances its functional properties. Hence, this hydrolysed soy protein isolate can be used as a cost-effective alternative to whey protein isolate, for vegans and patients.

Identification and enzymatic properties of arginine decarboxylase from Aspergillus oryzae.

Aspergillus oryzae spores, when sprinkled onto steamed rice and allowed to propagate, are referred to as rice "koji." Agmatine, a natural polyamine derived from arginine through the action of arginine decarboxylase (ADC), is abundantly produced by solid state-cultivated rice koji of A. oryzae RIB40 under low pH conditions, despite the apparent absence of ADC orthologs in its genome. Mass spectrometry imaging revealed that agmatine was accumulated inside rice koji at low pH conditions, where arginine was distributed. ADC activity was predominantly observed in substrate mycelia and minimally in aerial mycelia. Natural ADC was isolated from solid state-cultivated A. oryzae rice koji containing substrate mycelia, using ammonium sulfate fractionation, ion exchange, and gel-filtration chromatography. The purified protein was subjected to sodium dodecyl sulfate poly-acrylamide gel electrophoresis (SDS-PAGE), and the detected peptide band was digested for identification by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The gene AO090102000327 of strain RIB40 was identified, previously annotated as phosphatidylserine decarboxylase (PSD), and encoded a 483-amino acid peptide. Recombinant protein encoded by AO090102000327 was expressed in Escherichia coli cells cultivated at 20°C, resulting in the detection of 49 kDa and 5 kDa peptides. The protein exhibited pyruvoyl-dependent decarboxylase activity, favoring arginine over ornithine and showing no activity with phosphatidylserine. The gene was designated Ao-adc1. Ao-ADC1 expression in rice koji at pH 4-6 was confirmed through western blotting using the anti-Ao-ADC1 serum. These findings indicate that Ao-adc1 encodes arginine decarboxylase involved in agmatine production.IMPORTANCEGene AO090102000327 in A. oryzae RIB40, previously annotated as a PSD, falls into a distinct clade when examining the phylogenetic distribution of PSDs. Contrary to the initial PSD annotation, our analysis indicates that the protein encoded by AO090102000327 is expressed in the substrate mycelia area of solid state-cultivated A. oryzae rice koji and functions as an arginine decarboxylase (ADC). The clade to which Ao-ADC1 belongs includes three other Ao-ADC1 paralogs (AO090103000445, AO090701000800, and AO090701000802) that presumably encode ADC rather than PSDs. Regarding PSD, AO090012000733 and AO090005001124 were speculated to be nonmitochondrial and mitochondrial PSDs in A. oryzae RIB40, respectively.

Risk stratification and prognosis prediction using cardiac biomarkers in COVID-19: a single-centre retrospective cohort study

ObjectiveThere is a need for a robust tool to stratify the patient’s risk with COVID-19. We assessed the prognostic values of cardiac biomarkers for COVID-19 patients.MethodsThis is a single-centre retrospective...

Comparative study of the commonly used protein quantitation assays on different Hymenoptera venoms: A fundamental aspect of Hymenoptera venom proteome analysis

Determination of protein concentration in Hymenoptera venoms requires an accurate and reproducible assay as the results will be used to support subsequent proteomic techniques employed in their analyses. However, all protein assay techniques have inherent strengths and weaknesses, demanding their assessment before selecting the most suitable platform for sample analysis. In this study, protein profiles of ant, honeybee, and wasp venoms, and bovine serum albumin (BSA) and hyaluronidase standards were qualitatively assessed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Their amino acid and protein concentration were quantitatively determined via Amino Acid Analysis (AAA). Amino acid concentration was determined via hydrolysis, derivatization, and chromatographic quantification. Protein concentration was estimated using four different protein concentration assays. The ratios of protein concentration in venom samples to protein standards were calculated, and the accuracy of the protein concentration assays was analysed relative to the concentration determined from AAA. SDS-PAGE analysis showed that BSA contained several protein bands, while hyaluronidase contained a mixture of peptide and protein bands. Ant and honeybee venoms contained a higher proportion of peptide bands, while wasp venom contained more protein bands. As determined by AAA, the ratio of protein concentration in Hymenoptera venoms varied between 1.01 and 1.11 to BSA, and between 0.96 and 1.06 to hyaluronidase. Overall, the Bradford assay was found to be the least accurate and the BCA assay was the most accurate in estimating protein concentration in Hymenoptera venoms. There was no significant advantage in using hyaluronidase as a standard or increasing incubation temperature of BCA assay when analysing Hymenoptera venoms. Diluent solutions containing phenol and human serum albumin interfered with Lowry-based assays.

Метод Фурье ИК-спектроскопии в исследовании эякулята в норме и с олигозооспермией

The optical properties of the components (plasma, spermatozoa, protein and a solution after protein isolation from plasma) of a series of 24 ejaculate samples according to spermatograms in normal and with oligozoospermia were studied by Fourier IR spectroscopy. The analysis of the complex of spectral data obtained for a series of samples of the "norm" category showed in 50% of cases the presence of pronounced pathology in the optical properties of ejaculate, plasma and sperm. For the remaining 50% of the samples, the presence of spermatozoa of satisfactory quality in terms of material composition (proteins, lipids, carbohydrates) was noted with already well-marked signs of pathology in the ejaculate and plasma. A comparative analysis of their optical properties made it possible to note that the absence of clearly defined Amide-I and Amide-II bands in the spectra and the presence of peptide bands in the 1593–1572 cm-1 region is a stable sign of an existing or incipient pathology. Samples of the oligozoospermia category are quite well identified by the spectra of the cellular part of the ejaculate. The results of the study may be useful in modernizing clinical techniques and diagnostic approaches to the problem of male fertility.

Structural Characterization and Properties of Modified Soybean Meal Protein via Solid-State Fermentation by Bacillus subtilis.

Soybean meal (SBM) is a high-quality vegetable protein, whose application is greatly limited due to its high molecular weight and anti-nutritional properties. The aim of this study was to modify the protein of soybean meal via solid-state fermentation of Bacillus subtilis. The fermentation conditions were optimized as, finally, the best process parameters were obtained, namely fermentation temperature of 37 °C, inoculum amount of 12%, time of 47 h, and material-liquid ratio of 1:0.58, which improved the content of acid-soluble protein. To explore the utilization of modified SBM as a food ingredient, the protein structure and properties were investigated. Compared to SBM, the protein secondary structure of fermented soybean meal (FSBM) from the optimal process decreased by 8.3% for α-helix content, increased by 3.08% for β-sheet, increased by 2.71% for β-turn, and increased by 2.51% for random coil. SDS-PAGE patterns showed that its 25-250 KDa bands appeared to be significantly attenuated, with multiple newborn peptide bands smaller than 25 KDa. The analysis of particle size and zeta potential showed that fermentation reduced the average particle size and increased the absolute value of zeta potential. It was visualized by SEM and CLSM maps that the macromolecular proteins in FSBM were broken down into fragmented pieces with a folded and porous surface structure. Fermentation increased the solubility, decreased the hydrophobicity, increased the free sulfhydryl content, decreased the antigenicity, improved the protein properties of SBM, and promoted further processing and production of FSBM as a food ingredient.

Monitoring the curing efficiency of a plant-based green engineered additive on caprine skin: a spectroscopic and chemometric novel approach

Environmental sustainability in industrial processing is one of the most fundamental requirements for sustainable development. The leather industry is known for its vast environmental pollution. But, green engineering may occur a paradigm shift in this sector. Plant-based goatskins curing is a cutting-edge green technology that holds the concept of pollution reduction through prevention on the upper stream of leather processing. The successful and rapid monitoring of the efficiency of this technology is the foremost demand for mass-level applications. In this study, ATR-FTIR spectroscopy was employed to monitor this technology's efficiency using a plant Polygonum hydropiper. Chemometrics was also applied to extract information from spectral data leading to an understanding of the inherent effect of studying preservatives on goatskins collagen chemistry. 10% plant-paste +5% NaCl, 10% plant-paste +10% NaCl, and 15% plant-paste +5% NaCl on goatskin were assessed by ATR-FTIR on 0th, 10th, and 30th days of preservation. The Spectral peak fitting (R2 = 0.99) area of amide I and II of collagen peptide bands revealed 2.73 to 1.33 times more structural suitability of studied goatskins than the control. Principal component analysis and Hierarchical cluster analysis showed that, after 30 days of curing, 15% paste +5% salt-rubbed goatskin collagen matrix significantly (around 50%) interacted with P. hydropiper. The interaction was superficial, as it happened before the opening up of collagen fibers. In conclusion, ATR-FTIR spectroscopy with Chemometrics can be an effective tool in evaluating the efficiency of goatskin curing and understanding the entire effect on collagen chemistry quickly.

Grain Characteristics, Moisture, and Specific Peptides Produced by Ustilaginoidea virens Contribute to False Smut Disease in Rice (Oryza sativa L.).

The fungus Ustilaginoidea virens, the causative agent of false smut in rice (Oryza sativa L.), is responsible for one of the severe grain diseases that lead to significant losses worldwide. In this research, microscopic and proteomic analyses were performed by comparing U. virens infected and non-infected grains of the susceptible and resistant rice varieties to provide insights into the molecular and ultrastructural factors involved in false smut formation. Prominent differentially expressed peptide bands and spots were detected due to false smut formation as revealed by sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and two-dimensional gel electrophoresis (2-DE) SDS-PAGE profiles and were identified using liquid chromatography-mass spectrometry (LC-MS/MS). The proteins identified from the resistant grains were involved in diverse biological processes such as cell redox homeostasis, energy, stress tolerance, enzymatic activities, and metabolic pathways. It was found that U. virens produces diverse degrading enzymes such as β-1, 3-endoglucanase, subtilisin-like protease, putative nuclease S1, transaldolase, putative palmitoyl-protein thioesterase, adenosine kinase, and DNase 1 that could discretely alter the host morphophysiology resulting in false smut. The fungus also produced superoxide dismutase, small secreted proteins, and peroxidases during the smut formation. This study revealed that the dimension of rice grain spikes, their elemental composition, moisture content, and the specific peptides produced by the grains and the fungi U. virens play a vital role in the formation of false smut.

ANTIMICROBIAL ACTIVITY OF LACTIPLANTIBACILLUS AND LEVILACTOBACILLUS STRAINS ISOLATED FROM FERMENTED OLIVE AND THEIR APPLICATION IN MILK AND PASTILLA LEAF BIOPRESERVATION

Biological preservatives are increasingly in demand as an alternative to chemicals, because of consumer’s health and environmental concerns. Lactic acid bacteria isolated from fermented olives, considered as extreme environment, may encompass significant antimicrobial activity against microorganisms involved in foodborne diseases and food spoilage. Three LAB strains (Levilactobacillus brevis S27, Lactiplantibacillus pentosus S42, and Lactiplantibacillus plantarum S62), isolated from fermented olive, were studied for their antimicrobial activity against pathogenic bacteria (Listeria innocua and E. coli) and yeast (Rhodotorula glutinis), involved in foodborne diseases and food spoilage. The microbial culture, cell-free supernatant (CFS) of all LAB strains showed inhibition zone (IZ) values ranges of 26.33-28.83 mm, 14.16-16.33 mm and 10-12.16 mm against R. glutinis, L. innocua and E. coli, respectively. The IZ values ranges obtained with NCFS (neutralized CFS at pH 7) against R. glutinis and L. innocua were respectively of 17.83-20.50 mm and 13.16-14.50 mm, whereas no inhibition was obtained against E. coli. Their bioactive molecules of proteinaceous nature showed that among the four peptide bands obtained, two bands of approximately 42 and 56 kDa are common for the three LAB strains (S27, S42 and S62). Two additional bands of 46 and 89kD are observed in S42 and S27, respectively. The minimum inhibitory concentration of 10-fold concentrated CFS (10xCFS) obtained was 5% against E. coli and 4.5% against L. innocua and R. glutinis. The 10xCFS of Lb. plantarum S62, selected as the most efficient strain against pathogens, demonstrated its effectiveness in decontamination of milk at concentrations of 0.45% (v/v) and 0.5% (v/v) against L. innocua and E. coli. The CFS allowed, at 0.5 mL/piece of 5 cm diameter, a total inhibition of R. glutinis, without affecting the color of Pastilla leaf. The CFS of Lb. plantarum S62 can be used as a bio-preservative against pathogenic bacteria (L. innocua and E. coli) in milk, and against R. glutinis in Pastilla leaf.

Identification and characterization of antimicrobial peptide (AMP) candidate from Gonggong Sea Snail (Leavistrombus turturella) extract.

This study aimed to explore the potency of Gonggong sea snail's (GSS) extract as an antimicrobial peptide (AMP) source. The results showed that the GSS meat extracts exhibited potential antimicrobial activity against Staphylococcus aureus and Escherichia coli. A peptide band with a molecular weight < 5kDa was obtained for the characterization of AMP candidates after separating the selected extract using SDS-PAGE, and the sequences were acquired by LC-ESI-MS analysis. The results of the bioinformatics analysis showed that the AMP candidate had a molecular weight of 1.4kDa, which consisted of 12 amino acid residues (RHPDYSVALLLR), with an α-helix structure, isoelectric point pH (pI) of 9.53, net charge + 1, a total hydrophobic ratio at 49.9%, protein-binding potential (Boman index) of 2.17kcal/mol, and hydrophobicity of + 13.67kcal/mol. Furthermore, MIC and MBC values of the extract and the < 10kDa fraction on both bacteria ranged from 0.50-1.03mg/ml. The GSS meat extract could reach the intracellular site of E. coli, while in S. aureus, it was localized in the cell membrane. These results can be baseline information for developing AMPs in natural bio-preservative exploration as food additives and pharmaceuticals.

Anti-Candida Potential of Peptides from Immature and Ripe Fruits of Capsicum chinense Jacq.

The objective of this work was to purify and evaluate the antifungal potential of peptides present in immature and ripe fruits of Capsicum chinense Jacq. (accession UENF 1706) on the medical importance yeasts. Initially the proteins of these seedless fruits were extracted, precipitated with ammonium sulfate at 70% saturation, followed by heating at 80°C. Subsequently, the peptide-rich extract was fractionated by DEAE-Sepharose anion exchange. The whole process was monitored by tricine-SDS-PAGE. The results revealed that the fraction retained in anion exchange column, called D2, of immature and ripe fruits significantly inhibit the growth of Candida albicans and C. tropicalis yeasts. Due to the higher yield, the D2 fraction of immature fruits was selected for further purification by reverse phase chromatography on HPLC, where sixteen different fractions (H1-H16) were obtained and these were subjected to antifungal assay at 50µgmL-1. Although almost all fractions tested had significant growth inhibition, the HI9 fraction inhibit 99% of the two yeasts tested. The effect of treatment with HI3, HI8, HI9, and HI14 fractions on the viability of yeast cells was analyzed due to their strong growth inhibition. We observed that only 50μgmL-1 of the HI9 fraction is the lethal dose for 100% of the cells of C. albicans and C. tropicalis in the original assay. Although the HI9 fraction had a fungicidal effect on both tested yeasts, we only observed membrane permeabilization for C. tropicalis cells treated with 50µgmL-1 of this fraction. Through mass spectrometry, we identified that the 6kDa peptide band of HI9 fraction showed similarity with antimicrobial peptides belonging to the plant defensin family.

Role of cathepsins B and D in proteolysis of yolk in the catfish Clarias gariepinus.

Yolk processing pathways vary in the oocytes of benthophil and pelagophil teleosts. The present study investigated the yolk processing pattern in the oocytes of the fresh water catfish Clarias gariepinus at vitellogenic, maturation, and ovulated stages. This study concludes that during maturation stage, an electrophoretic shift in the major peptide band on Polyacrylamide gel electrophoresis (PAGE) occurs due to a decrease in the size of the yolk protein. The PMF spectrum of corresponding peptides from vitellogenic and ovulated oocytes revealed a difference in the minor ions. A minor difference in the molecular weight of the corresponding peptides occurs due to a difference in their amino acid composition. Maximal activity of the proteases cathepsin D and cathepsin B was observed in the vitellogenic oocytes, thus confirming their role in the processing of yolk. A significant transient increase in the activity of cathepsin B in the mature oocytes also suggests its role in oocyte maturation.

Impact of the frying temperature on protein structures and physico‐chemical characteristics of fried surimi

SummaryIn this work, protein structures and properties and physico‐chemical characteristics of surimi fried at different temperatures were studied. The effect of frying on surimi protein structure was characterised by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS‐PAGE), intrinsic fluorescence, surface hydrophobicity, intermolecular interaction and Fourier transform infrared spectroscopy (FT‐IR). SDS‐PAGE analysis observed the appearance of new peptide bands and the weakening of myosin heavy‐chain and actin bands after frying. In addition, frying damaged the hydrogen bond and ionic bond but promoted formation of the disulphide bond. Moreover, β‐sheet and random coil were increased after frying, while α‐helix and β‐turn were decreased. After frying, the surface hydrophobicity of fried surimi decreased and the fluorescence maximum emission wavelength showed a red shift. The above changes indicated occurrence of protein denaturation and degradation, which were dependent on the frying temperature. Moreover, the effect of the frying temperature on physicochemical properties of fried surimi was characterised by measuring the hardness, oil absorption, porosity and water absorption capacity of fried surimi. The moisture loss, oil uptake, porosity and water absorption capacity of the fried surimi increased gradually with the frying temperature. However, the hardness of fried surimi was not positively correlated with the frying temperature but strongly dependent on the porous structure. These results showed that the physico‐chemical properties of the fried surimi were dependent on not only degree of protein denaturation but also the porous structure.

Detection of salivary citrullinated cytokeratin 13 in healthy individuals and patients with rheumatoid arthritis by proteomics analysis.

The immune response to citrullinated peptides in the mucosa has been suggested to play an important role in the transition from pre-onset rheumatoid arthritis (RA) to clinically evident RA. Although there are reports indicating the presence of anti-citrullinated peptide antibodies in the saliva, few studies have reported citrullinated peptide detection in human saliva. This study aimed to identify citrullinated peptides in human saliva and discuss their clinical significance. Saliva samples were collected from 11 patients with RA and from 20 healthy individuals. Citrullinated peptides were detected using an anti-modified citrulline (AMC) antibody. Saliva from the healthy individuals was subjected to two-dimensional protein electrophoresis to isolate citrullinated peptides, which were analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and mass spectrometry by peptide mass fingerprinting. The results were corroborated by immunoprecipitation (IP)-western blotting. The signal intensities of the bands precipitated with anti-cytokeratin 13 (CK13) and AMC antibodies were quantified. The signal intensity ratio of the band produced by the AMC antibody was divided by that of the band produced by the anti-CK13 antibody to calculate the citrullinated CK13 (Cit-CK13) ratio. A citrullinated peptide band corresponding to a molecular weight of approximately 50 kDa was detected in the saliva of healthy individuals, and identified as CK13 via mass spectrometry and IP-western blotting. No significant difference was observed between the salivary Cit-CK13 ratios of patients with RA and healthy participants (p = 0.605). This is the first study to show that Cit-CK13 is present in human saliva, and that there is no significant difference between the Cit-CK13 ratios of patients with RA and healthy individuals, suggesting that salivary Cit-CK13 content and RA development may not be associated. The physiological and pathological roles of Cit-CK13 in the oral cavity, and its responsiveness to mucosal immunity, remain unknown and will be the subject of further investigation.

Milk-clotting properties on bovine caseins of a novel cysteine peptidase from germinated Moringa oleifera seeds

A cysteine peptidase was previously identified from germinated Moringa oleifera seeds, but its milk-clotting properties on bovine caseins was still unclear. In this study, this novel cysteine peptidase (MoCP) showed preferential activity on κ-casein (κ-CN), with greater hydrolytic activity compared with calf rennet, whereas weak hydrolysis of α-casein and β-casein made MoCP suitable for application in cheesemaking and may yield various functional peptides. All 3 evaluated caseins were hydrolyzed to form relatively stable peptide bands within 3 h of proteolysis with MoCP. Cleavage sites were determined by gel electrophoresis, liquid chromatography mass spectrometry/mass spectrometry, and peptide sequencing, which revealed that cleavage of κ-CN by MoCP occurred at residue Ile129-Pro130 and generated a 14,895.37-Da peptide. The flocculation reaction between MoCP and κ-CN determined by 3-dimensional microscopy with super-depth of field revealed that the initial 30 min of reaction were key for milk coagulation, which may affect curd yield. Overall, the findings presented herein suggest that the cysteine peptidase from germinated M. oleifera seeds can be considered a promising plant-derived rennet alternative for use in cheese manufacture.

Evaluation of cardiac injury with biomarkers and echocardiography after COVID-19 infection.

Coronavirus disease 2019 (COVID-19) causes cardiovascular damage in the acute period. Knowledge regarding cardiovascular damage after COVID-19 infection and during longer-term follow-up is currently limited. In our study, we aimed to compare cardiac and inflammatory markers and echocardiographic parameters between patients who had recovered from COVID-19 and control group. A total of 224 individuals were included, comprising 126 patients with a history of COVID-19 and 98 healthy controls. The demographic characteristics of the two groups were similar. Complete blood count, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), N-terminal pro-B type natriuretic peptide (NT-ProBNP), D-dimer, haemoglobin A1C, troponin T and creatine kinase myocardial band (CK-MB) levels were compared between both groups. The mean follow-up period of the COVID-19 group was 58.39 ± 39.1 days (range:10 - 180 days post-COVID-19). Red cell distribution width (RDW), ESR, CRP, NT-ProBNP, D-dimer and troponin T values were significantly higher in the COVID-19 group compared to the control group. Left ventricular ejection fraction (LVEF) was significantly lower in the COVID-19 group. Left ventricular diastolic diameter (LVDD) and incidence of pericardial effusion were higher in the COVID-19 group. For multivariate analysis, possible factors identified by univariate analysis were subjected to multivariate logistic regression analysis to determine independent predictors of COVID-19. Among these factors, RDW, CRP and LVEF were independently higher in the COVID-19 group than in the control group. We conclude that although the clinical and prognostic significance of cardiac and other inflammatory markers in the acute phase of COVID-19 is known, we found that these biomarkers and echocardiography parameters can also be used in the follow-up of cardiac injury for a mid-term period post-infection.

Antibacterial, Sperm Immobilization and Spermicidal Activities of Bacteriocins Produced by Vaginal Lactobacilli

Abstract Lactobacillus bacteriocin is an interesting compound playing a dual spermicidal/bacteriocidal role so that this compound can be developed as an agent that can be able to replace the unsafety chemical, nonoxynol-9. The present study aimed to investigate the antibacterial, sperm immobilization, and spermicidal activities of bacteriocins that were produced from vaginal lactobacilli. Nine of 932 cell-free supernatants exhibited potent antibacterial activities against the standard bacterial strains and the pathogenic Niesseria gonorrhoeae. Ion exchange-purified bacteriocins B84/7 F2 demonstrated the lowest minimum inhibitory concentration and the highest bacteriocin activity against the tested pathogens. The isolate B84/7 was then identified as Lactobacillus crispatus. The rapid killing activity was exerted within 15 minutes after being exposed to the tested bacteria, and also significantly inhibited the exponential growth of the tested pathogen. Among 48 semen of volunteers, the median time of sperm immobilization of ion-exchange purified B84/7 F2 bacteriocin (18.70 mg/mL) was 30.42 seconds. Within 60 seconds, spermicidal activities of the partial fractionated and ion-exchange purified B84/7 F2 at the undiluted concentration were 83.67 and 80.75%, respectively. Its activity will significantly decline at pH &gt; 8.0 or after being treated with alkaline and proteolytic enzymes. Two peptide bands of this bacteriocin were 7.08, and 8.81 kDa after being detected on a tricine SDS-PAGE gel. In-depth characteristics of this bacteriocin should be further investigated regarding the mode of action and purification. These findings can be applied to develop as the protecting agent of sexually transmitted infections especially gonorrhea, and unwanted pregnancy. Keywords: Antibacterial activity, Bacteriocins, Neisseria gonorrhoeae, Sperm immobilization, Spermicidal activity, Vaginal lactobacilli

Unreceptivity – a phenomenon induced by male accessory gland secretions in female Helicoverpa armigera

Unreceptivity, a phenomenon generally observed in female insects following mating, was investigated by simulating a mating situation in Helicoverpa armigera females by injecting male accessory glands and duplex (MAG-duplex) extracts sans sperm. Injection of extracts into the abdomen of virgin females induced unreceptivity. The virgin females started behaving like mated females by rejecting the males by avoiding the advances made by the latter to mate. Unreceptivity was observed in about 93% of the females on the day of injection, which reduced to 82% on the second scotophase compared to controls. However, on the third day, 75% of them reverted back to receptivity that was comparable to virgin count. The Tricine–SDS-PAGE of MAG-duplex of virgin and mated male moths revealed the conspicuous absence of a low molecular weight (&lt; 7 kDa) peptide band in the mated moths, and the possibility of being delivered to female at the time of mating. MALDI-TOF spectra of the same extracts showed the presence of several peptides &lt; 7 kDa, further, the absence of them in mated moths.

Proteomic analysis of oocytes retrieved from in vitro cultured ovine small antral follicles and large antral follicles cultured with amphiregulin, neuregulin-1 and tumour necrosis factor-a

Protein components change markedly during follicular development in the ovary. In this study, a proteomics approach was used to evaluate changes in proteins during different size follicles viz small antral follicles (SAFs) and large antral follicles (LAFs) culture exposed with different growth factors. The optimum and elevated doses of amphiregulin (AREG) or neuregulin (NRG-I) or tumour necrosis factor-α (TNF-α) were used for culture of SAFs and LAFs and then oocytes were retrieved for analysis of secretory protein by SDS-PAGE. SAFs were cultured in media containing 150 ng of AREG, NRG1 and TNF-α and LAFs in media containing 50 ng of AREG, NRG1 and TNF-α. The average yield of protein from oocytes retrieved from SAFs when cultured with 150 ng of AREG, NRG-1 and TNF-α was 0.0012, 0.0016 and 0.0010 mg/ml respectively. When cultured with oocytes retrieved from LAFs in 50 ng AREG, 50 ng NRG-I and 50 ng TNF-α, the corresponding values were 0.0026, 0.0021 and 0.0014 mg/ml respectively. The SDS-PAGE profile of the oocytes retrieved from culturing of SAFs and LAFs in different doses of AREG, NRG-I and TNF-α revealed no peptide bands.

Fine-tuned method to extract high purified proteins from the seagrass Halophila stipulacea to be used for proteome analyses

We report a fine tuned procedure to obtain high proteins yield and quality from the marine plant Halophila stipulacea. Two tissue fixation methods have been applied; sampled plants were preserved in RNAlater or frozen in liquid nitrogen. Both fixed plants have been processed following three different protein extraction protocols; we used a protocol optimized in this work, reported as Procedure 1 in which very small amount of tissue were used for the extraction in trichloroacetic acid/water, followed by trichloroacetic acid/acetone. The second protocol, reported as Procedure 2, is the well-established protocol developed for P. oceanica; following this protocol, proteins have been extracted from fivefold tissue amount than Procedure 1, without the trichloroacetic acid/acetone step. In the Procedure 3 the reverse approach between sample fixation and extraction protocols used in the previous two procedures have been applied. The lowest yield of 2.49 ± 0.18 mg/g of tissue is obtained from RNAlater preserved plants processed with the Procedure 2, while the highest protein yield of 5.88 ± 0.22 mg/g is obtained from the RNAlater preserved plants processed with the Procedure 1. These last protein samples gave the best resolved profile of peptide bands in SDS-PAGE showing higher proteins purity than those in all the other samples. The gel-based proteomics approach by the uHPLC-µESI-MS/MS analyses and bioinformatics against a customized dataset of genomic and transcriptomic seagrass sequences have been performed. Hundreds of proteins were identified from the Procedure 1 samples; lesser protein identification was obtained from Procedure 2 samples and no significant identifications have been detected from Procedure 3 samples. Statistics of classes of proteins that were identified in each procedures were also reported. Supplemental data for this article is available online at https://doi.org/10.1080/11263504.2021.2020355 .