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At least 19 recordsLinked to original sources
PubMed1977

Biosynthesis of a alpha-amylase and protease by Streptomyces olivaceus 142. III. Some aspects of alpha-amylase induction.

The induction of alpha-amylase in Streptomyces olivaceus 142 depends on the phase of growth of culture and the nature of the carbon sources upon which the cells were grown prior to exposure to inducer. The most susceptible to induction are cells from the initial hours of growth and glycerol -- grown cells. Reduction in the susceptibility of cells to alpha-amylase induction is probably a result of catabolic repression.

Amylases↗
PubMed1977

Biosynthesis of alpha-amylase and protease by Streptomyces olivaceus 142. I. Regulation of alpha-amylase activity.

Streptomyces olivaceus 142 produces amylase in the logarithmic phase of growth of the culture. The synthesis of the enzyme is induced by maltose and starch. In the case of maltose the synthesis is induced by a contaminating compound, probably being a higher than maltose polymer of glucose. The synthesis of amylase is negatively controlled by catabolic repression. The level of the activity of the enzyme depends not only on the biosynthesis but also on it proteolytic degradation.

Amylases↗
PubMed1976

Isolation and characterization of isoenzymes of human salivary and pancreatic alpha-amylase.

Human salivary and pancreatic alpha-amylase (1,4-glucan 4-glucanohydrolase, EC 3.2.1.1) were separated by electrofocusing. In the first case we obtained six isoenzymes with isoelectric points of pH 5.70, 5.72, 6.23, 6.32, 6.73 and 6.88. Human pancreatic alpha-amylase has been separated into eight isoenzymes with isoelectric points of pH 5.72, 5.77, 5.88, 6.05, 6.23, 6.69, 6.72 and 6.95. Some of the isoenzymes were shown to be sialoproteins; others representing about 80% of the total activity did not contain neuraminic acid. The molecular weight of the non-sialoproteinic isoenzymes was found to be about 47 000 in all cases.

Amylases↗
PubMedDate not supplied

[Effect of the composition of the nutrient medium on the synthesis of acid-fast alpha-amylase by different strains of Aspergillus].

The capacity of 86 strains of the Aspergillus fungus to synthesize acid stable alpha-amylase was examined. The strains of Asp. niger showing a high capacity of synthesizing the enzyme were isolated. Repeated cultivation of the selected cultures on the Minoda agar medium led to a 200% increase in the enzyme activity in the submerged culture. Addition of sodium nitrate to the Minoda medium during submerged cultivation allowed a 3-fold increase of the synthesis of acid stable alpha-amylase.

Amylases↗
PubMed1976

Purification and properties of an alpha-amylase inhibitor from wheat.

Four inhibitors of alpha-amylase (EC 3.2.1.1) were separated from an alcohol extract of wheat by ion-exchange chromatography on DE52-cellulose. One inhibitor, which showed the greatest specificity for human salivary amylase relative to human pancreatic amylase, has been purified by the following steps: (a) alcohol fractionation (60--90%) of water extract (b) ion-exchange chromatography on QAE-Sephadex A-50; (c) re-chromatography on DE52-cellulose and (d) gel filtration on Sephadex G-50. The purified inhibitor is 100 times more specific for human salivary amylase than for human pancreatic amylase. It shows an electrophoretic mobility of 0.2 on disc gel electrophoresis and a molecular weight of about 21 000. This inhibitor contributes about 16% to the total salivary amylase inhibiting power of the wheat extract.

Amylases↗
PubMed1975

Quantitative determination of anomeric forms of sugar produced by amylases. V. Anomeric forms of maltose produced in the hydrolytic reaction of substituted phenyl alpha-maltosides catalyzed by saccharifying alpha-amylase from B. subtilis.

1. Hydrolyses of phenyl alpha-maltoside and its derivatives with various substituents (p-NO2, p-C1, p-CH3, p-C2H5, and p-C(CH3)3) catalyzed by saccharifying alpha-amylase from B. subtilis3 [EC 3.2.1.1] were studied under conditions such that the products were only maltose and the corresponding phenols (1), in order to determine quantitatively the anomeric form of the sugar produced from each substrate. 2. At the optimum pH of this enzyme (pH-5.4), maltose released from all the substituted substrates studied was entirely in the beta-form. These results are in remarkable contrast to the previous finding that alpha-maltose is exclusively produced from unsubstituted phenyl alpha-maltoside by this enzyme (2). 3. At pH 6.18 and 6.73, maltose produced from unsubstituted phenyl alpha-maltoside (øM) or p-tert-butylphenyl alpha-maltoside (PTBøM) was a mixture of alpha- and beta-anomers, the ratio being dependent on pH as follows: For øM, the percentage of alpha-anomer was 100% (pH 5.4), 80 (pH 6.18), and 55% (pH 6.73), whereas for PTBøM, the percentage of beta-anomer was 100% (pH 5.4), 75% (pH 6.18), and 60% (pH 6.73).

Amylases↗
PubMed1977

Biosynthesis of alpha-amylase and protease by Streptomyces olivaceus 142. II. Biosynthesis of protease.

Streptomyces olivaceus 142 produces proteolytic enzymes de novo, mainly in the stationary phase of growth. The highest activity of the enzymes was observed in media containing maltose or fructose. In media supplemented with glucose, glycerol or starch the activity was lower. The synthesis of proteases is subject to catabolic repression. The proteolytic activity is reduced by phosphate buffer.

Chloramphenicol↗
PubMed2026

Unlocking the molecular engineering of Geobacillus glycoside hydrolases as a source of industrial biocatalysts.

This review examines Geobacillus sensu stricto as a source of thermostable glycoside hydrolases (GH) for biomass conversion, food processing, and enzyme engineering. Recent peer-reviewed literature was assessed with emphasis on taxonomy, genome-based Carbohydrate-Active Enzymes (CAZyme) prediction, biochemical validation, structural data, and engineering case studies. Taxonomic boundaries were interpreted using current Anoxybacillaceae frameworks, with Parageobacillus treated as a related comparator rather than as Geobacillus. The strongest evidence supports GH13 alpha-amylases, xylan-active systems, beta-xylosidases, and selected accessory enzymes. Recent studies also show that genome mining must be coupled with enzymatic assays and product profiling because CAZyme annotation alone does not prove industrial function. Molecular engineering has improved relevant traits, including the longer thermal half-life of engineered G. stearothermophilus alpha-amylase variants, the increased catalytic efficiency of oligo-alpha-1,6-glucosidase variants, and improved AmyS expression in Bacillus subtilis. Geobacillus glycoside hydrolases are best interpreted as process-specific, engineerable biocatalytic templates. Their translation requires reliable taxonomy, functional validation, structural interpretation, scalable expression and testing on realistic substrates. This synthesis also recognises current limitations: many predicted CAZymes still lack biochemical validation, complete cellulolytic systems remain less mature than xylan- and starch-active systems, and scale-up data remain scarce.

Geobacillus↗
PubMed1975

Amylase of the thermophilic actinomycete Thermomonospora vulgaris.

alpha-Amylase of the thermophilic actinomycete Thermomonospora vulgaris was partially purified. Maximal enzyme activity was obtained at 60degreeC and pH 6.0. KM value was l.4%. The effect of some metal salts on enzyme activity was studied. Enzyme activity was inhibited by by KCN, EDTA, and iodoacetate. Inhibition by EDTA was completely nullified by CaCl2, but the inhibition by iodoacetate was not overcome by 2-mercaptoethanol. Exposure of the enzyme to pH 7.0 and 9.0 for 2 hr. did not affect the enzyme, but exposure to pH 3.0 for few minutes completely inactivated the enzyme. Exposure of the enzyme to 60degreeC resulted in an appreciable inactivation and exposure to 80degreeC completely inactivated the enzyme. Addition of CaCl2, 2-mercaptoethanol, or enzyme substrate the 60degreeC exposed enzyme. However, bovine serym albumin had a protective effect when the enzyme was exposed to 60degreeC but not to 80degreeC. The enzyme was stable in the presence of 8 M urea.

Amylases↗
PubMed2026

Genomic profiling of digestion related enzymes in Anopheles aquasalis a major coastal neotropical malaria vector.

Digestive genes are fundamental for the development and survival of mosquitoes and can serve as a target for the development of strategies for mosquito control or vector-borne disease prevention. Genes related to digestion were identified in the genome of the neotropical malaria vector Anopheles aquasalis by similarity. We used reciprocal BLAST with annotated digestion proteins for Anopheles gambiae. Orthology and evolutionary analyses were performed using MEGA with a bootstrapped phylogenetic tree constructed by the neighbor-joining method, and copy number variation was measured by the standard deviation of the average copy number in each gene family. We identified 241 genes related to digestion in An. aquasalis: 56 genes related to carbohydrate digestion, 51 genes for lipid digestion, and 134 genes for protein digestion. Phylogenetic relationships with other anophelines show that An. aquasalis genes are closely related to those of neotropical mosquitoes Anopheles darlingi and Anopheles albimanus. Orthologous gene clusters are conserved in important families of all four species. Some of these conserved genes are of interest for studies on controlling mosquito vectors, such as larvicidal toxin receptor genes, alpha-amylase, alpha-glucosidase, and maltase; important target genes for transmission-blocking vaccines, such as aminopeptidase N1 and carboxypeptidase B; and the major intestinal serine proteases, such as trypsins and chymotrypsins, which can positively or negatively affect Plasmodium development in the midgut. These data provide a better understanding of digestion-related genes in American anopheline mosquitoes and may support further fundamental and applied studies aimed at malaria control.

Animals↗
PubMed1976

[Chemical Investigation of Chronic Pancreatitis].

We differentiate indirect and direct methods. The indirect methods include the examination of the blood (ESR, blood picture, electrolytes, especially calcium, for the exclusion of hyperparathyroidism, status of fat and liver enzymes, activity of alpha-amylase and lipase. More informative than a serum determination is the measurement of the amylase activity in the 24-hour urine. The detection of chymotrypsin in the stool can be recommended as an investigative test also for use in general practive in collaboration with a central laboratory.- The direct methods include investigation of the duodenal juice with measurement of pH, bicarbonate, of the activities of chymotrypsin, trypsin, lipase and amylase. For excluding of a disturbance of the carbohydrate metabolism in addition to blood sugar determinations, glucose tolerance and tolbutamide tests, the determination of insulin activity is indicated.

Acute Disease↗
PubMed1976

Investigations on the function of the rat forestomach.

The functions of the rat forestomach and upper digestive tract were studied. The pH values, alpha-amylase activity, quantitative estimates of microorganisms, and emptying rates were higher in the forestomach than in the glandular stomach. Rats with surgically removed forestomachs lived without complications for more than 1 yr. Their alimentary hyperglycemia was higher and shorter than in controls. The significance of rich microflora present in the conventional forestomach is not known, although in this function between man and ruminants were discussed.

Amylases↗
PubMed2026

Design, synthesis and biological evaluation of hydroxybenzothiazole-linked benzothiazole/benzoxazole conjugates as potent dual α-amylase and α-glucosidase inhibitors.

The current study focuses on the synthesis and evaluation of novel Hydroxybenzothiazole-Linked Benzothiazole/Benzoxazole Conjugates to target Diabetes Mellitus (DM) by inhibiting α-amylase and α-glucosidase. Spectroscopic methods, including 1H and 13C NMR spectroscopy, were employed to confirm the structures of newly synthesized conjugates. The findings of in-vitro analysis displayed that the synthesized derivatives inhibited α-amylase and α-glucosidase enzymes with IC50 values ranging from 3.65 ± 0.20 μM to 32.15 ± 3.20 μM on α-amylase and 5.92 ± 0.80 μM to 35.60 ± 3.40 μM on α-glucosidase, in contrast to the reference drug Acarbose (α-amylase IC50 = 8.25 ± 0.80 μM; α-glucosidase IC50 = 10.75 ± 1.10 μM). Among the series 9a-9f and 10a-10f, analogs 10 f, 10b, 9b, and 9e displayed superior anti-diabetic activity compared to the reference drug Acarbose. The inhibitory activity of these conjugates can be attributed to their favorable and stable interactions with critical amino acid residues of targeted enzymes, as revealed through molecular docking analysis. ADMET predictions and drug-likeness evaluations showed favorable pharmacokinetic features, while DFT investigations revealed electronic insights related to bioactivity. Experimental outcomes and in silico support display that these potent Hydroxybenzothiazole-Linked Benzothiazole/Benzoxazole Conjugates were comparable to an existing diabetic mellitus inhibitor while conserving an acceptable safety profile, specifying potential for further therapeutic development and optimization against diabetic Mellitus.

Benzothiazoles↗
PubMed2026

Multistrategy metabolic engineering of Talaromyces pinophilus for α-amylase production from lignocellulosic biomass.

Filamentous fungi are important hosts for industrial enzyme production. Growing demand for α-amylase has increased reliance on food-derived carbon substrates, necessitating fungal strains that efficiently utilize nongrain biomass. In this study, Talaromyces pinophilus Y117 was metabolically engineered to produce α-amylase from lignocellulosic biomass. A strong cellobiohydrolase I gene (cbh1) promoter (Pcbh1Tru) was identified to drive expression. Multiple rounds of multilocus integration of the α-amylase gene were performed using homologous multicopy genomic sequences as recombination arms with a Cre/loxP-based recyclable selection system, yielding the multicopy strain Tp4, which achieved 4124.5 U/mL α-amylase activity in shake-flask fermentation with corncob powder as the sole carbon source. To minimize enzyme degradation, the protease gene 8538 was deleted using the Cre/lox2272 system, generating Tp4Δp. This strain showed a 50% increase in shake-flask α-amylase activity (6208.4 U/mL). In 3-L bioreactor cultivation, Tp4Δp exhibited excellent production performance, achieving 26 712.2 U/mL α-amylase activity. When corncob powder was used as the sole substrate, the cellulose and hemicellulose degradation rates reached 90.00% and 70.01%, respectively, and the enzyme yield reached 213 697.5 U per gram of corncob powder. This engineered strain demonstrates strong potential for industrial applications. The synthesis-degradation synergistic optimization strategy provides a practical approach for engineering filamentous fungal cell factories to produce enzymes directly from lignocellulosic biomass. One sentence summary Metabolic engineering of Talaromyces pinophilus through promoter optimization, multicopy integration, and protease deletion enables efficient α-amylase production from lignocellulosic biomass, achieving 26 712 U/mL in bioreactor fermentation.

Talaromyces↗
PubMed2026

Acute pre-exercise oral intake of cacao polyphenols attenuates central fatigue development during sustained low-intensity ankle dorsiflexion exercise in healthy young male adults.

This double-blind, randomized, crossover study investigated whether acute cacao polyphenol (CP) ingestion attenuates neuromuscular fatigue in 19 healthy young male adults. After consuming CP or placebo, participants performed sustained isometric ankle dorsiflexion at 25% of maximal voluntary isometric contraction (MVIC) torque until task failure. Neuromuscular function (MVIC torque, voluntary activation [VA%], doublet torque) and electromyographic activity were assessed before, immediately after, and during recovery (1 and 5&#x2009;min). Salivary chromogranin A and &#x3b1;-amylase were measured at baseline and 1&#x2009;min post-task. Only VA% and chromogranin A showed significant condition &#xd7; time interactions (p&#x2009;=&#x2009;0.027-0.039). VA% significantly decreased from before to immediately after the task and 1&#x2009;min post-task in both conditions (p&#x2009;&#x2264;&#x2009;0.002), with significantly higher values in the CP condition than in placebo immediately after and 1&#x2009;min post-task (p&#x2009;&#x2264;&#x2009;0.037). Chromogranin A significantly increased from baseline to 1&#x2009;min post-task in the placebo condition (p&#x2009;<&#x2009;0.001) but not in the CP condition (p&#x2009;=&#x2009;0.083). These findings suggest that acute CP ingestion attenuates the decline in central motor drive and autonomic stress responses following strenuous exercise, without altering performance or peripheral recovery, supporting its potential as a nutritional strategy for modulating central fatigue.

Humans↗