Amylase

About: Amylase is a research topic. Over the lifetime, 14164 publications have been published within this topic receiving 296069 citations.

Inhibition of starch digestion by the green tea polyphenol, (−)-epigallocatechin-3-gallate

Abstract: cope Green tea has been shown to ameliorate symptoms of metabolic syndrome in vivo. The effects could be due, in part, to modulation of postprandial blood glucose levels. Methods and results We examined the effect of coadministration of (−)-epigallocatechin-3-gallate (EGCG, 100 mg/kg, i.g.) on blood glucose levels following oral administration of common corn starch (CCS), maltose, sucrose, or glucose to fasted CF-1 mice. We found that cotreatment with EGCG significantly reduced postprandial blood glucose levels after administration of CCS compared to control mice (50 and 20% reduction in peak blood glucose levels and blood glucose area under the curve, respectively). EGCG had no effect on postprandial blood glucose following administration of maltose or glucose, suggesting that EGCG may modulate amylase-mediated starch digestion. In vitro, EGCG noncompetitively inhibited pancreatic amylase activity by 34% at 20 μM. No significant change was induced in the expression of two small intestinal glucose transporters (GLUT2 and SGLT1). Conclusions Our results suggest that EGCG acutely reduces postprandial blood glucose levels in mice when coadministered with CCS and this may be due in part to inhibition of α-amylase. The relatively low effective dose of EGCG makes a compelling case for studies in human subjects.

Secretion of acid hydrolases and its intracellular source in tetrahymena pyriformis

Abstract: Axenic Tetrahymena pyriformis, syngen 1, mating type II cells were grown in Cox's defined medium. When washed and transferred into nonnutrient dilute salt solution or resuspended in the defined medium, the intact cells secrete acid hydrolases into the medium. Cells starving in the salt solution release in 5 hr about two-thirds of their β-glucosidase, β-N-acetylglucosaminidase, α-glucosidase, and amylase activities, about one-third of their deoxyribonuclease and phosphatase activities, smaller amounts of ribonuclease, and only a negligible fraction of their proteinase activity and protein content. During this period there is practically no change in the enzyme activities (except for a sudden increase of ribonuclease activity) and protein content of cells and medium together. Cells resuspended in the nutrient medium secrete enzymes as do the starved cells, but replace this loss, so that there is a continuous increase of the activities in the total system. According to isopycnic centrifugation experiments performed in sucrose gradients, the source of the hydrolases is a special population of lysosomes which disappear from the cells during starvation. This population equilibrates in the high density region of the gradients and contains the various acid hydrolases in about the proportion in which these enzymes appear in the medium.

Saccharification of marine microalgae using marine bacteria for ethanol production.

Abstract: The saccharification of marine microalgae using amylase from marine bacteria in saline conditions was investigated. An amylase-producing bacterium, Pseudoalterimonas undina NKMB 0074 was isolated and identified. The green microalga NKG 120701 was determined to have the highest concentration of intracellular carbohydrate and was found from our algal culture stocks. P. undina NKMB 0074 was inoculated into suspensions containing NKG 120701 cells and increasingly reduced suspended sugars with incubation time. Terrestrial amylase and glucoamylase were inactive in saline suspension. Therefore, marine amylase is necessary in saline conditions for successful saccharification of marine microalgae.