Amylase

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

Ontogeny of enzymatic activities in fed and fasting turbot, Scophthalmus maximus L.

Abstract: The presence and localization of acid and alkaline phosphatase, non-specific proteases, aminopeptidase, amylase, non-specific esterase and lipase was investigated by histoenzymologic methods in fed and fasting turbot from day 1 to day 40 post-hatching and compared with published data. Alkaline phosphatase and aminopeptidase activities were delected at day 1 in the distal region of the developing digestive tube. At day 3 (opening of the mouth) aminopeptidase and alkaline phosphatase activities were found all along the intestine. Sites of non-specific esterase and protease activities became apparent in the digestive tract at days 2 and 3 respectively. Amylase was present in the exocrine pancreas at day 3 and in the lumen of the intestine at day 4. Acid phosphatase was active in the cellular structure surrounding the yolk stores and in the lipid droplets at day 1 and in the intestinal epithelium at day 3. Lipase was found at day 15 when the larvae metamorphose into juveniles. All the investigated enzymes were detected in fasting animals, except for lipase. However, the intensities of the enzymatic activities were weaker in the fasting specimens relative to the fed specimens between days 7 and 10.

Effect of osmo- and hydropriming of chickpea seeds on seedling growth and carbohydrate metabolism under water deficit stress

Abstract: Seven-day-old seedlings obtained from seeds primed with mannitol (4%)and water showed three to four fold more growth with respect to root and shootlength in comparison with seedlings obtained from non-primed seeds. Seedlingswere grown under water deficit stress conditions created by 15% polyethyleneglycol (PEG) 6000 in the medium. Priming of chickpea seeds with NaCl and PEGwasnot effective in increasing seedling growth under these water deficit stressconditions. The activities of amylase, invertases (acid and alkaline), sucrosesynthase (SS) and sucrose phosphate synthase (SPS) were higher in shoots ofprimed seedlings. An increase in the activities of SS, and both the acid andalkaline invertases was also observed in roots of primed seedlings. The twofoldincrease in specific activity of sucrose phosphate synthase was observed incotyledons of primed seedlings. The higher amylase activity in shoots of primedseedlings enhanced the rapid hydrolysis of transitory starch of the shootleading to more availability of glucose for shoot growth and this was confirmedby the low level of starch in shoots of primed seedlings.

Starch digestion and absorption in nonruminants.

Abstract: Starch digestion and absorption is augmented appreciably by physical processing of grain or legume and by heating to 100 degrees C for several minutes before its ingestion. Starch, a polysaccharide composed of alpha 1,4-linked glucose units (amylose) and alpha 1,4-1,6-linked branched structure (amylopectin), is cleaved in the duodenal cavity by secreted pancreatic alpha-amylase to a disaccharide (maltose), trisaccharide (maltotriose), and branched alpha-dextrins. These final oligosaccharides are hydrolyzed efficiently by complimentary action of three integral brush border enzymes at the intestinal surface: glucoamylase (maltase-glucoamylase, amyloglucosidase), sucrase (maltase-sucrase) and alpha-dextrinase (isomaltase). The final monosaccharide glucose product is then cotransported into the enterocyte along with Na+ by a specific brush border 75-kDa transport protein in the rate-limiting step for overall starch assimilation. By virtue of this sequential luminal and membrane digestion followed by glucose transport, starch is assimilated in a very efficient manner in nonruminants.