scholarly journals Casein Proteolysis in Bioactive Peptide Production: Optimal Operating Parameters

2020 ◽  
Vol 50 (4) ◽  
pp. 726-735
Author(s):  
Irina Milenteva ◽  
Natalia Davydenko ◽  
Aleksandr Rasshchepkin
Keyword(s):  
Dairy Products ◽  
Proteolytic Enzymes ◽  
Thermal Exposure ◽  
Biologically Active ◽  
Antigenic Determinants ◽  
Diabetic Patients ◽  
Unhealthy Lifestyle ◽  
Molecular Weights ◽  
Working Parameters ◽  
Casein Hydrolysates

Introduction. Public health is gradually deteriorating as a result of unhealthy lifestyle and diet, which triggers allergic reaction to certain foods. Milk and dairy products are rich in biologically active substances, which makes them a good dietary supplement for athletes, diabetic patients, etc. However, this popular food contains allergens, for instance, such proteins as αS1-casein, αS2-casein, β-casein, and κ-casein. Therefore, one of the most urgent tasks of modern food science is to reduce the allergenic properties of casein. Heat treatment is an option, but thermal exposure leads to denaturation and produces new antigenic determinants, e.g. epitopes. Biotechnological processing is a more promising method. It is based on the catalytic properties of proteolytic enzymes. Enzymes make it possible to obtain a protein hydrolyzate with amino acids of various molecular weights. The present research provided the optimal working parameters of casein proteolysis by various enzymes (endopectidases), namely trypsin, chymotrypsin, and thermolysin. Study objects and methods. Casein hydrolysates are casein-based biopeptides, and casein is an accessible and valuable milk protein. Trypsin, chymotrypsin, and thermolysin were used as proteases. The experiment was based on standard methods. Results and its discussion. At 47 ± 2°C and pH 7.5 ± 0.2, the production of low-molecular-weight components of casein hydrolyzate proved feasible when thermolysin was used at a ratio of 1:100 for 24.00 ± 0.05 h, and chymotrypsin and trypsin – at a ratio of 1:25 for 24.00 ± 0.05 h. Conclusion. The resulting casein hydrolysates contain biologically active peptides and can be used in formulations of low-allergy functional dairy products in allergy-friendly, sports, and baby diets.

Natural Stilbene Polyphenols as Yarrowia lipolytica Cell Cytoprotectors at Heat Stress

2021 ◽  
Vol 37 (6) ◽  
pp. 14-24
Author(s):  
N.N. Gessler ◽  
E.P. Isakova ◽  
Yu.I. Deryabina
Keyword(s):  
Heat Stress ◽  
Heat Shock ◽  
Yarrowia Lipolytica ◽  
Respiration Rate ◽  
Catalase Activity ◽  
Thermal Exposure ◽  
Biologically Active ◽  
Yeast Cells ◽  
Protective Properties ◽  
Cyanide Resistance

Using the extremophilic yeast of Yarrowia lipolytica, a new model has been proposed to study the protective properties of stilbene polyphenols, namely resveratrol and pinosylvin, under heat shock. It was shown that a short-term thermal exposure of yeast cells (55 C, 25 min) led to a 40% decrease in the colony-forming ability of the population, a fivefold decrease in the respiration rate, and a growth of cyanide resistance and catalase activity, which indicated the adaptive yeast response to heat stress. Under these conditions, natural biologically active stilbenes, resveratrol and pinosylvin, at a concentration of 10 μM each increased yeast survival by 28% and 13%, respectively. In heat shock, resveratrol additionally raised catalase activity, while pinosylvin increased the cell respiration rate and decreased cyanide resistance and catalase activity. The results obtained indicate that resveratrol acts as a mild pro-oxidant inducing antioxidant protection during the adaptive response of the yeast to heat shock. Unlike resveratrol, pinosylvin increases cell survival stabilizing mitochondrial function and preserving the ATP-generating component of respiration. Yarrowia lipolytica yeast, polyphenols, stilbenoids, resveratrol, pinosylvin, cellular respiratory activity, heat shock, superoxide dismutase, catalase

COMPARATIVE ASSESSMENT OF MILK PROTEIN COAGULANTS OF DIFFERENT ORIGIN

2021 ◽  
Author(s):  
А.Г. КРУЧИНИН ◽  
С.Н. ТУРОВСКАЯ ◽  
Е.Е. ИЛЛАРИОНОВА ◽  
А.В. БИГАЕВА
Keyword(s):  
Dairy Products ◽  
Milk Protein ◽  
Proteolytic Enzymes ◽  
Raw Materials ◽  
Technical Information ◽  
Animal Origin ◽  
Technological Properties ◽  
Recombinant Enzymes ◽  
Rennet Coagulation ◽  
Milk Coagulation

Потребность в увеличении количества и качества производимой молочной продукции стимулирует исследования, направленные на повышение эффективности переработки молочного сырья, что, в свою очередь, невозможно без изучения технологических свойств молока и функционально необходимых ингредиентов, применяемых в производстве различной молочной продукции. На основе научно-технической информации международных и российских баз данных, систематизированной в рамках изучаемой тематики, представлен обзор научных работ о коагулянтах белков молока различного происхождения, применяемых при кислотной, кислотно-сычужной и сычужной коагуляции. Установлено, что в российской и международной производственной практике востребованы коагулянты животного, микробного и рекомбинантного происхождения. Наибольшим спросом среди коагулянтов животного происхождения пользуется химозин, получаемый из желудков телят. Ферменты микробного и рекомбинантного происхождения отличаются более стабильным качеством и низкой стоимостью, но их производство, основанное на методах генной инженерии, вызывающих предубеждение у большинства потребителей, практически полностью сосредоточено за рубежом. При условии повышения лояльности потребителей ферменты рекомбинантного происхождения могут стать наиболее перспективными функциональными ингредиентами. Исследования потенциала различных протеолитических ферментов растительного происхождения выявили невысокий технологический эффект их применения. Рассмотренный материал позволяет прогнозировать перспективность научных исследований по выявлению механизмов коагуляции молока и новых эффективных и универсальных коагулянтов совокупно с селекционной практикой отбора животных, направленной на улучшение технологических свойств молочного сырья. The need to increase the quantity and quality of dairy products encourages research aimed at improving the efficiency of processing dairy raw materials, which, in turn, is impossible without studying the technological properties of milk and functionally necessary ingredients used in the production of various dairy products. On the basis of scientific and technical information from international and Russian data bases, systematized within the framework of the subject under study, a review of scientific works on milk protein coagulants of various origins used in acid, acid-rennet and rennet coagulation is presented. It is established that coagulants of animal, microbial and recombinant origin are in demand in the Russian and international production practice. The greatest demand among coagulants of animal origin is chymosin, obtained from the stomachs of calves. Microbial and recombinant enzymes are characterized by more stable quality and lower cost, but their production, based on genetic engineering methods that cause prejudice among most consumers, is almost entirely concentrated abroad. If consumer loyalty is increased, recombinant enzymes may become the most promising functional ingredients. Studies of the potential of various proteolytic enzymes of plant origin revealed a low technological effect of their use. The considered material allows us to predict the prospects of scientific research to identify the mechanisms of milk coagulation and new effective and universal coagulants together with the breeding practice of animal selection, aimed at improving the technological properties of dairy raw materials.

Purification and characterization of tuberculin-active components from BCG

1975 ◽  
Vol 21 (12) ◽  
pp. 2019-2027
Author(s):  
M. Laguerre ◽  
R. Turcotte
Keyword(s):  
Physicochemical Properties ◽  
Guinea Pigs ◽  
Gel Filtration ◽  
Biologically Active ◽  
Polyacrylamide Gels ◽  
Active Components ◽  
Purification And Characterization ◽  
Molecular Weights ◽  
Antigenic Activity

The tuberculin activity of protoplasmic extracts isolated from living BCG was purified successively by gel filtration on Sephadex G-100 and G-75, and by electrophoresis on 7.5% and on gradient (6–18%) polyacrylamide gels. The tuberculin-active fractions, as determined in BCG-sensitized guinea pigs, were used as the starting material for each of the following fractionation steps.The physicochemical properties and the antigenic activity of the biologically active fractions have shown that a single component, or only a few ones with similar properties, possessed high tuberculin activity. These active components were proteins having relatively high molecular weights (about 72 000) and could behave as antigens.

scholarly journals Modelling the Partial Demineralization Process of Cow Milk by Superpro Designer

2017 ◽  
Vol 45 (2) ◽  
pp. 9-12 ◽  
Author(s):  
Attila Csighy ◽  
András Koris ◽  
Gyula Vatai
Keyword(s):  
Dairy Products ◽  
Membrane Filtration ◽  
Biologically Active ◽  
Cow Milk ◽  
Chemical Components ◽  
Unit Operations ◽  
Payback Time ◽  
Operation Parameters ◽  
Reactor Models ◽  
Milk And Dairy Products

Abstract Milk and dairy products contain a number of biologically active compounds (proteins, lipids, vitamins and minerals) that are essential for human nutrition. The most common procedures for demineralization are based on ion exchange-, nanofiltration- and electrodialysis-based technologies. In this study, the application of membrane filtration-based partial demineralization of cow milk was investigated and the process modelled. Using design equations, the partial demineralization process was designed and the economy of the process calculated. The modelling and simulation of the partial demineralization process was carried out by the SuperPro Designer programme. As the first step the unit operations of the demineralization technology were defined using the tools of the programme. The SuperPro Designer possesses industrial tools with reactor models, chemical components, a database of mixtures, and price estimations. By analysing the influence of the operation parameters, the feasibility of the proposed process was investigated. From the results of the modelling it can be concluded that the partial demineralization process can be successfully implemented, achieving the expected demineralization rates with a relatively good payback time of two years.

scholarly journals HYBRID FORMATION BETWEEN BACTERIAL ENDOTOXINS

1967 ◽  
Vol 126 (1) ◽  
pp. 63-79 ◽  
Author(s):  
Jon A. Rudbach ◽  
Kelsey C. Milner ◽  
Edgar Ribi
Keyword(s):  
Bile Salt ◽  
Sodium Deoxycholate ◽  
Enteric Bacteria ◽  
Biologically Active ◽  
Antigenic Determinants ◽  
Hybrid Formation ◽  
Bacterial Endotoxins ◽  
New Type ◽  
The Individual

When endotoxins extracted from enteric bacteria were mixed in the presence of sodium deoxycholate, and the bile salt was subsequently removed by dialysis or by extraction with ethanol, a new type of endotoxin was formed. The latter material was as biologically active as the original endotoxins and possessed a combination of antigenic determinants that were previously unique to each of the individual endotoxins in the mixture. This hybrid formation between endotoxins was detected by immunodiffusion and radioautography and by quantitative precipitation procedures.

The role of hemorheological disorders in the pathogenesis of hemorrhagic pancreonecrosis

2021 ◽  
Author(s):  
Н.П. Александрова ◽  
В.И. Карандашов ◽  
А.В. Варданян
Keyword(s):  
Sialic Acid ◽  
Shear Rate ◽  
Electrophoretic Mobility ◽  
Blood Viscosity ◽  
Proteolytic Enzymes ◽  
Biologically Active ◽  
Erythrocyte Aggregation ◽  
Control Group ◽  
Mechanical Resistance

Введение. Вопросы патогенеза острого панкреатита и панкреонекроза до настоящего времени остаются в центре внимания исследователей и клиницистов. До сих пор до конца не выяснена роль изменений в системе гемостаза и гемореологических нарушений в развитии этого заболевания. Цель исследования: установить роль гемореологических нарушений в патогенезе геморрагического панкреонекроза и изучить специфику механизма этих расстройств. Материалы и методы. Обследовано 29 пациентов с геморрагическим панкреонекрозом (12 женщин и 17 мужчин) в возрасте от 23 до 60 лет. Исследовали вязкость крови, показатель гематокрита, количество эритроцитов и их диаметр, агрегацию, электрофоретическую подвижность, деформируемость и механическую резистентность эритроцитов, белковый состав плазмы, содержание сиаловой кислоты в плазме и в эритроцитах, параметры липидного обмена, содержание кальция и фибриногена в крови,фибринолитическую активность крови и агрегационную активность тромбоцитов, гемокоагуляционная активность исследована методом тромбоэластографии. Для определения нормальных значений исследованных показателей было обследовано 15 практически здоровых лиц (7 женщин и 8 мужчин). Результаты. У больных панкреонекрозом самым грубым нарушениям подвергаются эритроциты: их механическая резистентность снижалась в 2 раза, объем увеличивался на 18,7%, деформируемость падала на 43,8%, количество снижалось на 8,75%, показатель гематокрита при этом оставался на уровне нормальных значений по причине увеличенного объема (сферичности) клеток; в 1,8 раза возрастала агрегация эритроцитов. Вязкость крови при скорости сдвига 1 c–1 увеличивалась в 3,3 раза, а при скорости сдвига 150 c–1 — в 1,58 раза по сравнению с нормой. Причиной повышения агрегации эритроцитов являлось снижение их электрофоретической подвижности на 35,9% из-за десиализации их мембран: концентрация сиаловой кислоты в клеточных мембранах была снижена на 20,8%, а содержание конъюгированной сиаловой кислоты в плазме увеличено в 2,25 раза по сравнению с нормальными значениями. Заключение. Гемореологические расстройства, которые возникают первоначально у больных геморрагическим панкреонекрозом как результат некротических изменений поджелудочной железы, с определенного, довольно раннего этапа сами становятся фактором патогенеза данного заболевания. Доминирующим фактором прогрессивного увеличения вязкости крови у больных панкреонекрозом является нарушение морфофункциональных и физико-химических свой ств эритроцитов на фоне высокой активности протеолитических ферментов, биологически активных аминов и крайней степени токсемии. Background. The pathogenesis of acute pancreatitis and pancreonecrosis is still the focus of researchers and clinicians. The role of hemorheological disorders in these diseases remain uncertain until now. Objectives: to define the role of hemorheological disorders in the pathogenesis of hemorrhagic pancreonecrosis and to study the specifics of the mechanism of these disorders. Patients/Methods. This study included 29 patients (12 women and 17 men, age of 23 to 60 years old) with hemorrhagic pancreatic necrosis. We examined blood viscosity, hematocrit and some erythrocyte properties as count, diameter, aggregation, electrophoretic mobility, deformability and mechanical resistance; other investigated parameters were plasma protein composition, plasma and erythrocytes sialic acid concentrations, lipids, total calcium and fibrinogen concentrations, blood fibrinolytic activity, platelets aggregation activity; total hemocoagulation activity was studied with thromboelastography. Control group contained 15 practically healthy individuals (7 women and 8 men). Results. Expressed disturbances of blood rheological properties, mostly in erythrocytes were detected in patients with pancreonecrosis. Red blood cells (RBC) showed 2-times decreasing of mechanical resistance, of their volume by 18.7%, of deformability by 43.8%, of count by 8.75%. Hematocrit remained normal level due to RBC increased volume (sphericity). RBC aggregation had been increased by 1.8 times. Blood viscosity at the shear rate of 1 s–1 was increased by 3.3 times and at the shear rate of 150 s–1 by 1.58 times. Raised erythrocyte aggregation was caused by a decrease of RBC electrophoretic mobility of 35.9%. Sialic acid concentration in RBC membranes was lower of 20.8% whereas conjugated sialic acid in plasma showed increasing by 2.25 times. Conclusions. RBC morphofunctional and physicochemical disturbances cause the increase in blood viscosity in patients with pancreonecrosis. It is distinguishing feature of hemorheological disorders in hemorrhagic pancreonecrosis developing, seems, due to high activity of proteolytic enzymes and biologically active amines. Of particular importance in hemorrhagic pancreonecrosis belong to platelet involving into intravascular coagulation.

Natural DNA Intercalators as Promising Therapeutics for Cancer and Infectious Diseases

2020 ◽  
Vol 20 (1) ◽  
pp. 19-32 ◽  
Author(s):  
Martyna Godzieba ◽  
Slawomir Ciesielski
Keyword(s):  
Infectious Diseases ◽  
Therapeutic Potential ◽  
Modern Medicine ◽  
Biologically Active ◽  
Substantial Part ◽  
Unhealthy Lifestyle ◽  
Natural Origin ◽  
Chemical Structures ◽  
Small Molecule Ligands ◽  
Improper Use

Cancer and infectious diseases are one of the greatest challenges of modern medicine. An unhealthy lifestyle, the improper use of drugs, or their abuse are conducive to the increase of morbidity and mortality caused by these diseases. The imperfections of drugs currently used in therapy for these diseases and the increasing problem of drug resistance have forced a search for new substances with therapeutic potential. Throughout history, plants, animals, fungi and microorganisms have been rich sources of biologically active compounds. Even today, despite the development of chemistry and the introduction of many synthetic chemotherapeutics, a substantial part of the new compounds being tested for treatment are still of natural origin. Natural compounds exhibit a great diversity of chemical structures, and thus possess diverse mechanisms of action and molecular targets. Nucleic acids seem to be a good molecular target for substances with anticancer potential in particular, but they may also be a target for antimicrobial compounds. There are many types of interactions of small-molecule ligands with DNA. This publication focuses on the intercalation process. Intercalators are compounds that usually have planar aromatic moieties and can insert themselves between adjacent base pairs in the DNA helix. These types of interactions change the structure of DNA, leading to various types of disorders in the functioning of cells and the cell cycle. This article presents the most promising intercalators of natural origin, which have aroused interest in recent years due to their therapeutic potential.

Quantitative cytochemistry: the basis of sensitive bioassays, for comparison of bio-and immuno-reactive hormone values.

1978 ◽  
Vol 24 (8) ◽  
pp. 1399-1407 ◽  
Author(s):  
L Bitensky ◽  
J Chayen
Keyword(s):  
Physiological Effect ◽  
Biologically Active ◽  
Antigenic Determinants ◽  
Target Cells ◽  
Biochemical Activity ◽  
Cytochemical Bioassay ◽  
Polypeptide Hormones ◽  
Increased Sensitivity ◽  
The Individual ◽  
Quantitative Cytochemistry

Abstract Cytochemistry now extends biochemistry down to the single-cell level. Special procedures have been developed for cutting sections of uniform thickness with no measurable or detectable artifact. The cytochemical bioassays use chromogenic reactions with the immediate precipitation of the resulting chromophore so that biochemical activity can be related to the individual cells constituting a tissue. This activity, in individual cells, is measured by scanning and integrating microdensitometry which also increases the sensitivity of cytochemical measurement over that of conventional biochemistry. A hormone, or indeed any biologically active substance, acting on its target cell, causes a change in the chemical activity of that cell that mediates the physiological effect of the hormone. By cytochemical methods one can assess such changes in the target cells even if these constitute only a small part of the target-organ; thus such methods are ideally suited to measuring chemical changes of this sort induced by the hormone. Such cytochemical bioassay of polypeptide hormones, done as "within-animal" assays, are about 1000-f0ld more sensitive than the equivalent radioimmunoassays and are as precise. Thus they have two advantages: (a) bioreactive hormone is measured rather than a composite of antigenic determinants characteristic of part of the hormone molecule and (b) their increased sensitivity allows discrimination between low normal and subnormal concentrations of the circulating hormone.

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