Enzymes Trypsin Research Articles

Enhancing Enzyme Stability and Functionality: Covalent Immobilization of Trypsin on Magnetic Gum Arabic Modified Fe3O4 Nanoparticles.

This study aimed to fabricate gum Arabic (GA)-coated Fe3O4 nanoparticles bearing numerous active aldehyde groups on their surface, followed by an assessment of their capability as a magnetic support for the covalent immobilization of the trypsin enzyme for the first time. FT-IR, XRD, TGA, and SEM results demonstrated the successful synthesis of GA-coated Fe3O4 nanoparticles, along with the covalent immobilization of the enzyme onto the support. Immobilization enhanced the relative enzymatic activity across a range of aqueous solution pH levels (ranging from 4 to 11) and temperatures (ranging from 20 to 80 °C) without altering the optimum pH and temperature for trypsin activity. Kinetic studies using Michaelis-Menten plots revealed changes in kinetic parameters, including a lower Vmax and higher Km for immobilized trypsin compared to the free enzyme. The immobilization onto magnetic gum Arabic nanoparticles resulted in an improved stability of trypsin in the presence of various solvents, maintaining a stability order comparable to that of the free enzyme due to the stabilizing effect of the support. The reusability results showed that the immobilized enzyme can retain over 93% of its activity for up to 15 cycles.

Production and Applications of Keratinases in Industry

Keratin is an insoluble protein with fibrous structure. It is mainly found in hair,feathers,nail,wool and horn of various animals. These animal accessories can be utilized as animals feed, amino-acids and fertilizers. This insoluble protein is very difficult to degrade and has extreme stability because it has disulfide bonds, hydrogen and hydrophobic interaction present in it. But keratin can be easily digested by keratinase enzyme. Keratinase is an extracellular enzyme. It also degrades keratin in prokaryotic organisms. Microorganisms that produce keratinase are species of Bacillus, Actinobacteria and fungi. It can also be obtained from Streptomyces, Aspergillus, Fervidobacterium, Xanthomonas, Chryseobacteriumand Vibrio. Keratinases produced by microbes arevery diverse due to their chemical as well as physical properties. It is a vigorous enzyme that can survive broad pH and temperature. Their optimum pH range is neutral to alkaline and their optimum temperature reported is 40°C to 60°C. And thermophiles have also been reported for stable microbial activity. Microbial keratinases are cheaply available as compared to conventional producers for keratinases production. They have gained great significance in biotechnology by acting on strong, inflexible cross linked polypeptide structure of keratin instead of ordinary proteolytic enzyme papain, trypsin or pepsin. They are mostly extracted by degrading keratin as substrate. Keratin substrates include feather, hair, wool,horn and nails. This degradation process is helpful in converting keratinous wastes in to fertilizer and poultry feed. Other renowned biotechnological implementations include removing hair from leather by using keratinase, development of bio-polymer from keratinous fiber, delivering drug, hydrolysis of prion proteins and detergent industry. They are also used in converting biomass in to biofuel that significantly boosts power preservation and recycling. The main problem for producing enzymes on large scale is their costly production procedures. This hurdle is overcome by utilizing keratin waste eg feathers of chicken as fermentation substrate on industrial scale. The benefit of utilizing this left over is extremely cost effective fermentation process of keratinase and the effluents are environmental friendly. Keratinase enzyme has become popular and provided newly effective and efficient way for managing waste products by using them on industrial scales as substrates which gives rise to environmental friendly industries for nonstop development.

RCB-4, a novel cyclic peptide, from Ricinus communis with anti-Trypanosoma cruzi activities

IntroductionChagas disease and toxoplasmosis caused by parasites Trypanosoma cruzi and Toxoplasma gondii affect more than 28 million people in poor areas of Latin America. There is an urgent need for therapeutic options as the treatments are related to efficacy, lower costs, and shorter administration time. Encouraged by the need to discover valid targets and new treatment options, we evaluated castor seed compounds against T. cruzi and T. gondii, considering their effects against proliferation, infection, and ultrastructure. Methodologycastor seed extract was fractionated by Gel-filtration chromatography using the Sephadex G-50 resin, and a fraction with MW <10 kDa, denoted LMWF, was isolated. The effect of this fraction against T. cruzi and T. gondii was investigated. LMWF was repurified by HPLC-Reverse Phase chromatography using C-18 column. The major isolated peptide, with antiprotozoal activity, denoted RCB-4, was characterized by SDS-PAGE, mass spectrometry, and “in silico” studies. To understand the mechanism of action underlying RCB-4 against T. cruzi activity, we investigated ultrastructural changes by optical and electron microscopy. ResultsRCB-4 is a cycle peptide with an MW of 2229.78 Dalton, and the sequence is “ARCCLVMPVPPFACVKFCSSA.” RCB-4 was resistant to trypsin, endo-Glu, and endo-Asp enzymes. It inhibited parasite growth by up to 50 % at 10 and 15 µg/mL (4.48 µM and 6.73 µM), inside and outside the cells, respectively. Ultrastructural studies showed that trypomastigotes incubated with natural or synthetic RCB-4 could impair T. cruzi proliferation and cause ultrastructural alterations, such as Golgi apparatus disorganization and mitochondrial swelling. ConclusionsCyclic peptides emerged as promising organic compounds with diverse pharmacological activities. They possess superior therapeutic value due to the particular structures conferring resistance to enzymatic degradation and higher bioavailability. Our data allow us to prospect using RCB-4 to combat the parasites T. cruzi and T. gondii.

Formulation and Biodegradation of Surface-Supported Biopolymer-Based Microgels Formed via Hard Templating onto Vaterite CaCO3 Crystals.

In recent decades, there has been increased attention to the role of layer-by-layer assembled bio-polymer 3D structures (capsules, beads, and microgels) for biomedical applications. Such free-standing multilayer structures are formed via hard templating onto sacrificial cores such as vaterite CaCO3 crystals. Immobilization of these structures onto solid surfaces (e.g., implants and catheters) opens the way for the formulation of advanced bio-coating with a patterned surface. However, the immobilization step is challenging. Multiple approaches based mainly on covalent binding have been developed to localize these multilayer 3D structures at the surface. This work reports a novel strategy to formulate multilayer surface-supported microgels (ss-MG) directly on the surface via hard templating onto ss-CaCO3 pre-grown onto the surface via the direct mixing of Na2CO3 and CaCl2 precursor solutions. ss-MGs were fabricated using biopolymers: polylysine (PLL) as polycation and three polyanions-hyaluronic acid (HA), heparin sulfate (HS), and alginate (ALG). ss-MG biodegradation was examined by employing the enzyme trypsin. Our studies indicate that the adhesion of the ss-MG to the surface and its formation yield directly correlate with the mobility of biopolymers in the ss-MG, which decreases in the sequence of ALG > HA > HS-based ss-MGs. The adhesion of HS-based ss-MGs is only possible via heating during their formation. Dextran-loading increases ss-MG formation yield while reducing ss-MG shrinking. ss-MGs with higher polymer mobility possess slower biodegradation rates, which is likely due to diffusion limitations for the enzyme in more compact annealed ss-MGs. These findings provide valuable insights into the mechanisms underlying the formation and biodegradation of surface-supported biopolymer structures.

Comparison of different papaya forms on the growth performance, immune response, antioxidative capacity, and caecal microbiota of Japanese Quails

Papaya is a sparsely branched tree and grows in many tropical and subtropical areas. Herein, this study compared the effects of papaya at 0.75 % as seeds meal (PSM), leaves meal (PLM), latex powder (PLP), or a mixture of them (PMIX) on the performances of Japanese quails. Two hundred unsexed Japanese quail (1st week-old) with an initial body weight of 21.08 ± 0.32 g were allocated into five experimental groups in cages with free access to water and test diets. Birds fed diets enriched with PSM, PLM, PLP, or PMIX for 55 weeks. The results showed that quail groups fed on papaya diets exhibited improved (P < 0.05) final weight, weight gain (WG), and feed conversion ratio (FCR) than the control. Dietary PLP or PMIX resulted in a remarkable WG enhancement, while PMIX reduced the FCR (P < 0.05). Activities of digestive enzymes (amylase, trypsin, and chymotrypsin) were enhanced (P < 0.05) with dietary papaya, especially in birds fed on PLP. Quails fed on PLM, PLP, or PMIX diets had reduced albumin/globulin ratio (A/G), triglycerides, total cholesterol, and low-density lipoprotein levels. At the same time, the level of high-density lipoprotein and the activity of aspartate aminotransferase increased (P < 0.001) by dietary PLP and PMIX. Moreover, higher total antioxidant capacity, superoxide dismutase, and lower malondialdehyde were recorded with papaya supplements than with the control. A similar trend was recorded for immunoglobulin G and M (IgG and IgM), phagocyte activity, and phagocyte index. Interestingly, low caecal harmful microbiota populations were observed in birds treated with papaya. In conclusion, the dietary inclusion of different papaya parts (leaves, seed, latex, and their mixture) can improve the productive performance, immunity, antioxidant indices, intestinal enzymes, and decline intestinal pathogens of growing Japanese quails.

Characterization of trypsin enzyme extracted from intestines of yellowfin tuna (Thunnus albacares) and bigeye tuna (Thunnus obesus) from Indonesian seawater

Recently, there has been a major concern about fisheries waste produced by tuna processing factories. There are many ways to handle the waste from tuna processing factories, specifically the tuna viscera which contains the stomach, pyloric caeca, kidneys, and intestines. The tuna viscera have been known as a source of digestive enzymes, one of them is a protease, including trypsin. The objective of this research was to analyze the enzymatic characteristic of trypsin extracted from two different tuna species. In this study, the trypsin extracted from the intestines of yellowfin and bigeye tuna was characterized by analyzing its enzyme activity as well as optimum temperature and pH, protein concentration, kinetic studies, and molecular weight. The results reveal that the enzyme activity and protein concentration observed in bigeye tuna (Thunnus obesus) were significantly higher than in yellowfin tuna (Thunnus albacares). In addition, trypsin bigeye and yellowfin tuna had the optimum temperature and pH from both crude extracts within the range of 50-60˚C and 7-8, respectively. Moreover, the molecular weights of trypsin enzymes extracted from yellowfin (T. albacares) and bigeye tuna (T. obesus) were 29 kDa.

Optimization of Selenium Inclusion Level in the Larval Diet of Labeo rohita.

The nutritional requirement of fish larvae remains a limiting factor in advanced aquaculture. Micronutrients are crucial for early development, but their dietary inclusion level in the larval feed of carps has not been standardized. The present study was executed to determine the optimum dietary inclusion level of organic and inorganic selenium in the larval feed of Rohu, Labeo rohita. A 35-day feeding trial in triplicate under semi-control conditions was conducted in 21 troughs divided into seven groups. Each trough (capacity 4.0 L) contained 200 larvae (average body weight 0.4mg). The first group (control) was reared on nano-particulate basal diet (CP 50%), while three groups Se-Na(0.5), Se-Na(1), and Se-Na(1.5) were fed basal diet supplemented with graded levels (0.5-1.5mg/kg diet) of inorganic form of Se, sodium selenite (Se-Na). The last three groups (Se-Met(0.5), Se-Met(1), and Se-Met(1.5)) were fed organic form of dietary Se, selenium methionine (Se-Met) at the same inclusion level as Se-Na. Results indicated the curvilinear relationship of dietary Se levels with body weight, activity of digestive enzymes (protease, amylase, lipases, and trypsin), and antioxidant enzymes (SOD, CAT, POD, and GSH-Px) activity, intestinal villi, width, and absorptive area. A positive correlation was observed with up to 0.5 and 1mg/kg diet of Se-Na and Se-Met, respectively; however, above these levels, a negative impact was observed. The upregulation of growth hormone mediator (IGF-1) and downregulation of heat shock protein (HSP-70) also followed a similar trend in response to Se-Na and Se-Met inclusion. Based on the results, 1mg/kg diet Se-Met could be considered the optimum level and is recommended for the early rearing of rohu larvae.

Bottom-up proteomics to investigate the X-ray irradiation effects on soft cheese

Food irradiation is an alternative technological process employed to preserve the hygienic quality of food and to extend its shelf life. In this work, three different types of soft cheese, mozzarella, robiola and primosale, were treated with X-rays at 1.0, 2.0 and 3.0 kGy to evaluate their effect on proteins and peptides using a bottom-up proteomic approach. Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-ToF-MS) and liquid chromatography coupled with MS through electrospray interface (LC-ESI-MS) were employed to analyse the peptide mixtures coming from the proteolytic digestion of soft cheese using both trypsin and chymotrypsin enzymes. We discovered 15 peptides most affected by X-rays that were sequenced by tandem MS and identified; ten of these discriminant peptides, generated from the cleavage of β-casein and α-casein (B. taurus), were localized on the proteins' secondary structure, highlighting a heightened susceptibility of random coils to X-ray irradiation. No additional post-translational modifications were found to be induced or emphasized by irradiation. For all studied cheese samples, the major spectral differences were encountered at 1.0 kGy, suggesting that such a dose was the most effective in promoting peptide bond cleavage. Some non-enzymatic and/or half-enzymatic peptides belonging to α-S1-, α-S2- and β-casein were also produced when varying X-ray doses.

The Exploration of Bioactive Peptides that Docked to SARS-CoV-2 Spike Protein from Goats’ Milk Beta-Casein by In Silico

Beta-casein in milk is known to be a bioactive peptide producer because of its amino acid sequence. Bioactive peptides have prospected molecules that can adhere with SARS-CoV-2 spike protein, so they can inhibit the virus from hooking up with human cell receptor protein. The research is aimed to find any peptides from goat’s milk beta-casein that are prospective candidates as SARS-CoV-2 spike protein inhibitors. Goat’s milk beta-casein was simulated as being digested by the digestive tract. Pepsin, trypsin, and chymotrypsin enzymes cut the beta-casein amino acids sequence into small peptides. Then, their bioavailability was predicted by Lipinski’s Rules of 5 (Ro5), any most fitted peptides to the rules will be simulated to dock to SARS-CoV2 spike protein besides Curcumin as the control ligand. Peptides with the best bind activity with the spike protein will be selected as inhibitor candidates. Peptide QPK is selected as a SARS-CoV-2 inhibitor candidate because it has better affinity energy than Curcumin or other selected peptides.

Therapeutic applications of sustainable new chitosan derivatives and its nanocomposites: Fabrication and characterization

Chitosan (CS) is a biologically active biopolymer used in different medical applications due to its biodegradability, biocompatibility, and nontoxicity. Nanotechnology is an exciting and quick developing field in medical applications. Nanoparticles have shown great potential in the treatment of cancer and inflammation. In the present work modification of chitosan and its (Ag, Au, or ZnO) nanocomposites by N-aminophthalimide (NAP) occurred through the reaction with epichlorohydrin (ECH) as a crosslinker in the presence or absence of glutaraldehyde (GA) under different reaction conditions using microwave irradiation to give modified chitosan derivatives CS-2, CS-6, and their nanocomposites. Modified chitosan derivatives were characterized using different tools. CS-2 and CS-6 derivatives displayed enhancement of thermal stability and crystallinity compared to chitosan. Additionally, CS-2, CS-6, and their nanocomposites exhibited improvements in antitumor activity against HeLa cancer cells and enzymatic inhibitory against trypsin and α-chymotrypsin enzymes compared to chitosan. However, CS-2 revealed the highest cell growth inhibition% toward HeLa cells (89.02 ± 1.46 %) and the enzymatic inhibitory toward α-chymotrypsin enzyme (17.13 ± 1.59 %). Furthermore, CS-Au-2 showed the highest enzymatic inhibitory against trypsin enzyme (28.14 ± 1.76 %). These results suggested that the new chitosan derivatives CS-2, CS-6, and their nanocomposites could be a platform for medical applications against HeLa cells, trypsin, and α-chymotrypsin enzymes.

Effects of acute hypoxic post-feeding condition on respiratory metabolism and digestion in yellow catfish (Pelteobagrus fulvidraco)

In this study, acute hypoxia was applied to two states of yellow catfish (Pelteobagrus fulvidraco) (non-feeding and feeding) for 48 h. We investigated the effects of acute hypoxia on the respiratory metabolism and digestive ability of yellow catfish (mean body length: 7.61 ± 0.52 cm). The results indicated that the respiratory frequency of yellow catfish under acute hypoxic post-feeding condition was rapidly accelerated and the oxygen consumption rate was reduced. The level of succinate dehydrogenase in the gills first increased and then significantly decreased (p < 0.05) and the level of lactate dehydrogenase significantly increased (p < 0.05). When the expression level of hypoxia-inducing factor was significantly increased (p < 0.05), the downstream coding genes (hexokinase 1 (hk1), phosphofructokinase (pfkla), and pyruvate kinase M1/2a (pkma)), key molecules of glycolysis, and the activity of crucial enzymes (hexokinase, phosphofructokinase, and pyruvate kinase) increased. At the same time, the glucose level dropped and the lactic acid level increased, indicating that the metabolic mode in the gills of yellow catfish under acute hypoxic post-feeding condition gradually changed to anaerobic, and the anaerobic glycolysis process was activated to provide the required energy for the body. In addition, we found that the activity of digestive enzymes (trypsin, lipase, and amylase) and expression levels of digestive genes (trypsin, lipase, and amylase) were inhibited in the liver and intestine of yellow catfish under the acute hypoxic post-feeding condition, indicating that their digestive ability was reduced. This may adversely affect growth and development. This study analyzed the effects of acute hypoxic post-feeding exposure on the respiratory metabolism and digestive capacity of yellow catfish, providing new insights into fish physiology and sustainable fish culture.

Trophic ecophysiology of the native green shore crab, Carcinus maenas, and the invasive Asian shore crab, Hemigrapsus sanguineus, in the rocky intertidal of Helgoland (North Sea)

The brachyuran crabs Carcinus maenas and Hemigrapsus sanguineus belong to the most ´successful´ invaders along the oceans coasts. In 2009, H. sanguineus appeared at the rocky intertidal of the island of Helgoland in the North Sea, where it encounters the native Green shore crab, C. maenas. H. sanguineus established a self-sustaining population, approaching in numbers and biomass that of C. maenas. Both species are considered to be opportunistic omnivores with variable food preferences and, thus, are potential competitors for food. To evaluate the intrinsic properties of either species to utilize food, we analyzed their stomach content, the morphology of the gastric mills, which shred the ingested food, the activities of digestive enzymes during a seasonal cycle, and the stable isotope ratios. A huge share of the stomach contents was macerated and, thus, could not be identified. The shares of animal food and algae food were almost equal in C. maenas but algae food dominated over animal food in H. sanguineus. The gastric mill of C. maenas shows blunt medial tooth and rounded lateral teeth, which indicates efficient grinding of a carnivorous diet. In contrast, the gastric mill of H. sanguineus shows sharp ridges, which facilitate cutting of algal food. The activities of the proteolytic enzymes trypsin and leucine-aminopeptidase were almost equal in both species with slightly higher activities in C. maenas in summer. The activities of the carbohydrases laminarinase and amylase dominated in H. sanguineus during all seasons. Stable isotope ratios indicate a higher degree of carnivory in C. maenas. The morphological and biochemical features indicate that C. maenas is better suited to utilize animal food and H. sanguineus algal food. Upon scarcity of animal food or severe competition with C. maenas, H. sanguineus may be able to increase the amount of algal food and to utilize it efficiently.

A common food additive (E452), hexametaphosphate, denatures the digestive enzyme trypsin

Phosphate additions in processed foods are a health risk that has been overlooked. This study examined the effects of a permitted food additive (E452; Sodium Hexametaphosphate (SHMP)) on trypsin solubility, structure, and stability at the intestinal physiological pH of 6.0. SHMP-treated trypsin samples were assessed for conformational changes and aggregation propensity using various spectroscopic and microscopic methods. Far-UV CD spectroscopy and intrinsic tryptophan fluorescence showed a rise in fluorescence intensity and alpha-helical structure up to 10 μM SHMP (∼1:1 M ratio). Secondary structure loss, tryptophan quenching, and solubility decrease with an increase in SHMP concentration (>10 μM). SHMP-treated trypsin aggregates showed poor ThT fluorescence. According to kinetics, SHMP leads to trypsin aggregation instantly. All spectroscopic studies showed trypsin denatured at above 10 μM SHMP. Thus, digestive enzyme structure and solubility loss will impair food digestion and health. Therefore, SHMP should be avoided as a food additive.

Investigation of the Impact of Saccharides on the Relative Activity of Trypsin and Catalase after Droplet and Spray Drying.

While using saccharides as stabilizers for therapeutic protein drying is common, the mechanisms underlying the stabilization during drying remain largely unexplored. Herein, we investigated the effect of different saccharides, trehalose dihydrate (TD), dextran (DEX), and hydroxypropyl β-cyclodextrins (low substitution-HP and high substitution-HPB), on the relative activities of the enzymes trypsin and catalase during miniaturized drying (MD) or spray drying (SD). For trypsin, the presence of saccharides, especially HP, was beneficial, as it significantly improved the enzyme activity following MD. The HPB preserved trypsin's activity during MD and SD. Adding saccharides during MD did not show a notable improvement in catalase activities. Increasing TD was beneficial during the SD of catalase, as indicated by significantly increased activity. Molecular docking and molecular dynamics simulations oftrypsin with HP or HPB revealed the influence of their substitution on the binding affinity for the enzyme. A higher affinity of HP to bind trypsin and itself was observed during simulations. Experimentally, activity reduction was mainly observed during MD, attributable to the higher droplet temperature during MD than during SD. The activities from the experiments and aggregation propensity from molecular modeling helped elucidate the impact of the size of protein and saccharides on preserving the activity during drying.

Monitoring of the Enzymatic Reactions Course by Differential Microwave Dielectrometry Method in Real Time

Enzymatic reactions are the basis of many biotechnological manufacturing and biomedical diagnostic procedures that require effective methods of monitoring over the reaction course. In the current paper, we present the results of the development of a new approach within the differential microwave dielectrometry method for the non-invasive monitoring of the course of enzymatic reactions based on the complex permittivity changes of these reactive mixture solutions in real time at a fixed frequency of 31.82 GHz. The dynamic studies of the dielectric parameters of selected enzymatic systems containing a protein substrate (immunoglobulin G, human serum albumin) and enzyme trypsin. The developed differential microwave dielectrometry setup has been performed to verify the proposed approach effectiveness for the enzymatic reaction monitoring in biomedical practice and the food industry. Our microwave dielectrometry results have been validated by the results of the UV-Vis spectrophotometry method for selected enzymatic systems. We propose a new approach to use the differential microwave dielectrometry method with high sensitivity (in average 0.5% and 3÷5% for the real and imaginary parts of the complex permittivity, respectively) to estimate the course of enzymatic reactions in real time.

Copper oxide nanoparticles exhibit variable response against enzymatic toxicity biomarkers of Moina macrocopa.

Growing toxicity of nanomaterials to aquatic organisms is a major area of concern as it is destroying the carefully evolved aquatic ecosystem and food web. Copper oxide nanoparticles (CuONPs) are among the top industrially manufactured nanomaterials having multifaceted applications in medicine, agriculture, energy, water technology, and other areas. However, reports on detailed scientific understanding behind toxic effects of CuONPs on aquatic organisms are scant. The present work reports on the interaction of CuONPs of 10 ± 05nm with an ecologically significant aquatic species, Moina macrocopa, at morphological and enzymatic levels. CuONPs were found to be severely toxic just within 48h of exposure as seen from the lethal value (48h LC50) of 0.137 ± 0.002ppm. Profiling of enzymatic toxicity biomarkers indicated variable response of CuONPs on selected enzymes of M. macrocopa at two sub-lethal concentrations (0.013 to 0.039ppm). While the activities of acetyl cholinesterase and digestive enzymes (trypsin, amylase) were found to be significantly (p < 0.001) lowered after exposure to CuONPs, the β-galactosidase activity was completely inhibited. Among the antioxidant enzymes that were assayed, superoxide dismutase and glutathione-S-transferase activity was found to increase (p > 0.001), while that of catalase decreased (p > 0.001, < 0.05) with increase in exposure to CuONPs. An upsurge of several folds was seen in the activity of alkaline phosphatase after exposure to CuONPs as compared to the control group. CuONPs accumulated in the gut region of M. macrocopa which provided an ideal environment for CuONP to interact and alter the enzymes inM. macrocopa. This report highlights the use of enzymes as sensitive biomarker to detect toxicity of trace amount of CuONPs in a very sensitive non-target crustacean species found in water bodies.

Evaluation of the Binding Properties of A New Phenylurea Appended Carbazole Compound to Pepsin/Trypsin by Computational and Multi-Spectral Analysis.

A novel carbazole compound, named 1-(9-ethyl-9H-carbazol-3-yl)-3-phenylurea (Cpu) was synthesized and its binding properties with protease enzymes (pepsin and trypsin) has been examined by steady-state fluorescence measurements, UV/vis absorption, infrared (FT-IR) and circular dicroism (CD) spectroscopies and also computational methods. The fluorescence experimental results indicated that the quenching mechanism of enzyme by Cpu is static process. The thermodynamic parameters (both negative ΔH/ΔS) and molecular docking results suggested that the binding of Cpu to pepsin/trypsin were driven by hydrogen bonds and van der Waals forces. Based on Förster's theory, the binding distance (r) between pepsin/trypsin and Cpu was calculated to be 3.072/2.784nm, which implies that non-radiative energy transfer occurs from enzyme to Cpu. Furthermore, absorption, CD, and FT-IR spectral analysis provided an evidence that the presence of Cpu induced notable changes in the secondary structures and microenvironmental of both pepsin and trypsin, supporting its significant influence on these enzymes.

Enhancing Nutrition and Palatability: The Development of Cooked Sausages with Protein Hydrolysate from Secondary Raw Materials for the Elderly

Currently, there is an increase in the use of preparations from collagen-containing raw materials in the production of meat products. The high functional and technological properties of such preparations make it possible to significantly improve the rheological properties of food products, as well as organoleptic indicators, and enrich meat products with dietary fibers. The aim of this study was to study the effect of an emulsion of 5% protein hydrolysate and 1% purslane powder on herodietic boiled sausages for the elderly. The results showed that the experimental samples of boiled sausages contained 15.44% protein, 6.6% fat, 4.2% carbohydrates and 71.1% moisture; this shows that boiled sausage with the addition of protein hydrolysate contains optimal chemical composition for dietary nutrition, a certain moisture index confirms the excellent consistency of boiled sausage. The change in the peroxide number was studied for 7 days. The results showed that the peroxide number did not change significantly from 2.0 meq/kg to 4.6 meq/kg. Thus, the addition of purslane with antioxidant properties helps to slow down the oxidation of fats and thereby increases the shelf life of boiled herodietic sausage. The results of the study of color characteristics showed stable color formation, which was influenced by an emulsion of collagen and purslane. It was found that products using emulsions from collagen-containing raw materials are characterized by a higher concentration of tyrosine due to the action of proteolytic enzymes (pepsin and trypsin)—from 728.1 mcg/mL (during the first three hours of hydrolysis) to 392.5 mcg/mL (during 6 h of hydrolysis)—which indicates a higher degree of protein digestibility these products. Thus, the addition of an emulsion of 5% protein hydrolysate and 1% purslane powder can be recommended for the production of boiled sausages with improved nutritional and taste properties.

Characterization of the structure, antioxidant activity and hypoglycemic activity of soy (Glycine max L.) protein hydrolysates

This study aimed to hydrolyze soy isolate protein (SPI) using five enzymes (alcalase, pepsin, trypsin, papain, and bromelain) in order to obtain five enzymatic hydrolysates and to elucidate the effect of enzymes on structural and biological activities of the resulting hydrolysates. The antioxidant and hypoglycemic activities of the soy protein isolate hydrolysates (SPIEHs) were evaluated through in silico analysis, revealing that the alcalase hydrolysate exhibited the highest potential, followed by the papain and bromelain hydrolysates. Subsequently, the degree of hydrolysis (DH), molecular weight distribution (MWD), amino acid composition, structure, antioxidant activities, and hypoglycemic activity in vitro of SPIEHs were analyzed. After enzymatic treatment, the particle size, polymer dispersity index (PDI), ζ-potentials, β-sheet content and α-helix content of SPIEHs was decreased, and the maximum emission wavelength of all SPIEHs exhibited red-shifted, which all suggesting the structure of SPIEHs was unfolded. More total amino acids (TAAs), aromatic amino acids (AAAs), and hydrophobic amino acids (HAAs) were found in alcalase hydrolysate. For 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, metal ion chelating activity, α-glucosidase inhibitory activity and α-amylase inhibitory activity, alcalase hydrolysate had the lowest IC50; alcalase hydrolysate and papain hydrolysate had the lowest IC50 for hydroxyl radical scavenging activity. Physiological activity of SPIEHs was evaluated thoroughly by 5-Axe cobweb charts, and the results revealed that alcalase hydrolysate exhibited the greatest biological activities.

Enzymatic hydrolysates from camel colostrum and milk proteins display inhibitory activity toward a key enzyme related to obesity

AbstractThis study aimed to investigate the anti-obesity potential of camel colostrum and milk proteins as well as their enzymatic hydrolysates. Camel colostrum and milk proteins were treated using six proteolytic enzymes (pepsin, trypsin, α-chymotrypsin, pancreatin, papain, and pronase). The degree of hydrolysis was measured to verify the degradation of proteins. The in vitro anti-obesity activity was evaluated using the pancreatic lipase inhibitory assay. Camel colostrum and milk protein hydrolysates exhibited different degrees of hydrolysis ranging from 17.69 to 43.97%. The protein content varied between 56.08–61.95% and 37.39–41.72% for camel colostrum and milk protein hydrolysates, respectively. The hydrolysates displayed significantly higher anti-obesity activity than the undigested proteins at all tested concentrations (P &lt; 0.05). Colostrum protein hydrolysate generated with pancreatin had the highest anti-obesity potential (59.92%). These results suggest that colostrum and milk protein hydrolysates could be used to formulate functional foods and nutraceuticals.