Do lipases and amylases of an endangered Indian carp Hypselobarbus pulchellus play a role in visceral fat dynamics; evidence of in vitro macromolecular interactions.

Fat depots or triglycerides are hydrolysed by the action of lipases in fish to be used for energy and/or for growth and reproduction. In herbivores fishes, de novo synthesis of lipids from non- lipid substrates (glucose) leads to fat deposits and/or fatty infiltration in organs especially on ovaries limiting its normal functions. This study was aimed to understand lipases from the digestive tract (DT) of adult Hypselobarbus pulchellus of different sizes, their partial purification, characterisation and their isozymes. In-vitro hydrolysis study on interaction of carbohydrate with proteins was evaluated to establish specific protein selection that combat undue glucose release. Results of the study identified four lipase isoenzymes of ~ mol. wt 19.88, 24.29, 32.86, 54.56 kDa with optimal pH of 3.5 and 8, pH stability between pH 5.5-10; optimal temperature at 35 °C and heat stability between 35 and 45 °C. Characterisation studies indicated presence of thiol group in their active site and Ca, Na and Zn ions activated lipase activity. Rice bran as carbohydrate source when used along with azolla (plant protein) and fish meal (animal protein) may combat undue release of excess glucose that leads to visceral fat formation in H. pulchellus as assessed from in vitro studies.

Retrogradation inhibition of starches in staple foods with maltotetraose-forming amylase.

To effectively inhibit the retrogradation of staple foods, the effects of maltotetraose-forming amylase(G4-amylase) on the short and long-term retrogradation of different staple starches such as rice starch (RS), wheat starch (WS), potato starch (PS) were studied. The results indicated that G4-amylase decreased the content of amylose. Amylose contents (21.09%) of WSG4 were higher than that (14.82%) of RSG4 and (13.13%) of PSG4. WS had the most obvious change in the chain length distribution of amylopectin. A chains decreased by 18.99% and the B1 chains decreased by 12.08% after G4-amylase treatment. Compared to RS (662 cP) and WS (693 cP), the setback viscosity of RSG4 (338 cP) and WSG4 (385 cP) decreased. Compared to RS (0.41), WS (0.45), and PS (0.51), the long-term retrogradation rate of RSG4 (0.33), WSG4 (0.31), and PSG4 (0.38) significantly reduced. It indicated that G4-amylase significantly inhibited the long-term retrogradation of WS, followed by RS and PS.

Investigating the effect of SUMO fusion on solubility and stability of amylase-catalytic domain from Pyrococcus abyssi.

Alpha amylase belonging to starch hydrolyzing enzymes has significant contributions to different industrial processes. The enzyme production through recombinant DNA technology faces certain challenges related to their expression, solubility and purification, which can be overcome through fusion tags. This study explored the influence of SUMO, a protein tag reported to enhance the solubility and stability of target proteins when fused to the N-terminal of the catalytic domain of amylase from Pyrococcus abyssi (PaAD). The insoluble expression of PaAD in E. coli was overcome when the enzyme was expressed in a fusion state (S-PaAD) and culture was cultivated at 18 °C. Moreover, the activity of S-PaAD increased by 1.5-fold as compared to that of PaAD. The ligand binding and enzyme activity assays against different substrates demonstrated that it was more active against 1 % glycogen and amylopectin. The analysis of the hydrolysates through HPLC demonstrated that the enzyme activity is mainly amylolytic, producing longer oligosaccharides as the major end product. The secondary structure analyses by temperature ramping in CD spectroscopy and MD simulation demonstrated the enzymes in the free, as well as fusion state, were stable at 90 °C. The soluble production, thermostability and broad substrate specificity make this enzyme a promising choice for various foods, feed, textiles, detergents, pharmaceuticals, and many industrial applications.

Chemical salivary composition and its relationship with periodontal disease and dental calculus

Aim: To determine the relationship between the chemical composition of saliva, periodontal disease and dental calculus. Methods: An observational analytical cross-sectional study was conducted with patients over 55 years of age. Ethical principles of autonomy and risk protection were applied according to the international standards. Sociodemographic and diagnosis variables (presence of dental calculus and periodontal status) were considered to measure salivary concentrations of glucose (by the glucose oxidase/peroxidase method, amylase (by the colorimetric test), urea (by the amount of indophenol), total protein (by the Bradford method) and albumin (by the nephelometric method). Patients chewed a sterile rubber band and 3 mL of stimulated saliva were collected. The samples were stored at -5 °C, centrifuged at 2,800 rpm for 10 min, and the supernatant was removed and stored at -20 °C. Data were presented as frequencies and proportions for qualitative variables and measures of central tendency and dispersion for quantitative variables. Data were analyzed by either analysis of variance or Kruskal Wallis test . A p value <0.05 was considered statistically significant. Results: Significant relationships were observed between the concentration of salivary urea and periodontal status (p = 0.03) and the presence of dental calculus and urea (p = 0.04) was demonstrated. Conclusions: A relationship between the salivary urea concentration and the presence of periodontal disease and dental calculus is suggested.

Propriedades físico-químicas do amido isolado, estudo de parâmetros enzimáticos durante o armazenamento e caracterização de enzimas amilolíticas em raízes de maca (Lepidium meyenii Walp) / Physico-chemical properties of isolated starch, enzymatic parameters during storage, and characterization of amylolytic enzymes of maca (Lepidium meyenii Walp. ) root

A maca (Lepidium meyenii Walpers) é uma planta herbácea bienal da família Brassicae, cultivada principalmente na região dos Andes da América do Sul. A parte subterrânea vem sendo consumida por muito tempo devido a seu valor nutricional e energético, mas é mais conhecida no mercado peruano e internacional por alegadas propriedades terapêuticas. Esta raiz apresenta até 76% de carboidratos, dos quais 30% é amido. Este trabalho teve como objetivos estudar: as propriedades físico-químicas e funcionais do amido isolado; os parâmetros enzimáticos durante o armazenamento e a purificação parcial de enzimas amilolíticas. Em relação às propriedades do amido, este apresentou um teor de amilose de 20% valor semelhante aos encontrados em raízes e tubérculos similares. A turbidez das suspensões de amido apresentou estabilidade durante o armazenamento. A temperatura de gelatinização e a viscosidade da pasta foram a 45,7° e 46°C, respectivamente. Com base nos dados obtidos, o amido de maca seria indicado para alimentos que requeiram temperaturas moderadas no processamento, não sendo apropriado para o emprego em alimentos congelados. Os parâmetros enzimáticos medidos tais como teor de amido total, teor de açúcares solúveis, atividade amilolítica total, atividade de α e β amilases, não mostraram diferenças significativas entre as medidas durante um período de armazenamento de 16 dias. As microscopias eletrônicas de varredura (MEV) dos grânulos de amido mostraram grãos íntegros com superfícies lisas, com algumas depressões ao redor dos grânulos os quais poderiam indicar o inicio de ataque enzimático, ou fraturas na purificação. Em relação à purificação de enzimas amilolíticas, foi possível separar uma fração ativa com a carboximetilcelulose (CMC) seguida de cromatografia liquida de alta resolução (CLAE) que permitiu a separação de duas frações protéicas, analisadas por eletroforese SDS-PAGE e eletroforese bidimensional (2D). Os polipeptídeos identificados no gel 2D apresentaram...

Maca (Lepidium meyenii Walpers) is a biennial herbaceous plant from Brassicae family, grown mainly in the Andes of South America. The underground part has been consumed for a long time due to its nutritional value and energy, but is best known in the Peruvian and international market for alleged therapeutic properties. This root has up to 76% carbohydrates, of which 30% is starch. This work aimed to study: the physico-chemical properties of isolated starch, the enzymatic parameters during storage and partial purification of amylases. In relation to the properties of starch, the amylose content showed a 20% value similar to those found in roots and tubers alike. The turbidity of starch suspensions was stable during storage. The gelatinization temperature and viscosity of the paste were 45.7 ° and 46 ° C, respectively. Based on data obtained from the starch of litter would be given to foods that require moderate temperatures in processing and is not suitable for use in frozen foods. The enzymatic parameters measured such as total starch content, soluble sugars, total amylolytic activity, activity of α and β amylases, showed no significant differences between the measures over a storage period of 16 days. Electronic microscopy (SEM) of starch granules showed grains with smooth surfaces, with some depressions around the granules which could indicate the beginning of enzymatic attack, or fractures in the purification. Regarding the purification of amylases was possible to separate an active fraction with carboxymethylcellulose (CMC) followed by high-resolution liquid chromatography (HPLC) which allowed the separation of two protein fractions, analyzed by SDS-PAGE and two-dimensional electrophoresis (2D ). The polypeptides had a molecular mass between 22 and 27 kDa and isoelectric points ranging from 4.8 to 7.3.