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Amylase
About: Amylase is a research topic. Over the lifetime, 14164 publications have been published within this topic receiving 296069 citations.
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TL;DR: The results suggest a direct effect of insulin on protein biosynthesis and zymogen discharge, most pronounced for amylase, in chronic alloxan diabetic animals.
Abstract: The three major phases in the secretory process in the exocrine pancreas (synthesis, intracellular transport, zymogen discharge) have been tested in vitro after changing circulating insulin levels in rats in vivo. One group of rats received a continuous infusion of glucose for periods up to 72 hours, which keeps blood glucose levels above 200 mg/100 ml and immunoreactive insulin (IRI) raised to 130 muU/ml. As a result of this treatment, amylase content in the pancreas increases by 25% while chymotrypsinogen and lipase show a comparable decrease. The rate of total protein synthesis increased by 40% after 48 hours of infusion. The basal and carbamylcholine stimulated discharge of newly synthesized proteins are not altered. The baseline discharge of amylase is increased significantly, while the discharge of lipase and chymotrypsinogen decreased below control levels. Similar results are obtained, if circulating insulin levels are raised by the application of glibenblamide (HB419) for a period of 24 hours. Protein synthesis increases by 26.5% and baseline discharge of amylase by 50%. In chronic alloxan diabetic animals the alteration of the exocrine pancreatic function depends on the severity of the diabetes and relates to circulating insulin levels. Animals with highest blood glucose levels and low or undetectable insulin concentrations show a disappearance of amylase from the exocrine pancreas and a depression of the rate of protein synthesis by 30%. The results suggest a direct effect of insulin on protein biosynthesis and zymogen discharge, most pronounced for amylase.
88 citations
TL;DR: It is suggested that the increased growth associated with the amylase diet during 0 to 3 wk can, in part, be explained by the increase in absorptive surface area, allowing for increased digestion of available nutrients coupled with increased enzyme activity for carbohydrate degradation from the supplemental enzymes.
88 citations
TL;DR: The effect of age and androgen level on enzyme activity and cellular structure has been determined in the mouse submaxillary gland in a manner similar to that determined in animals with high testosterone levels.
Abstract: 1. The effect of age and androgen level on enzyme activity and cellular structure has been determined in the mouse submaxillary gland.
2. A new protease which resembles chymotrypsin in its substrate specificity has been characterized in the gland.
3. Activity of the chymotrypsin- and trypsin-like proteases and renin increased considerably in male mice concomitantly with proliferation of granules in the secretory tubules of the gland.
4. The androgen dependence of the chymotrypsin- and trypsin-like enzymes, renin and the organelles within the secretory tubules was confirmed in castrated male mice. The activity of these enzymes increased and correlated with the appearance of intracellular granules in the secretory tubules when the castrated male mice and in addition female mice were treated with testosterone preparations.
5. Kallikrein, a closely related protease, and amylase increased in activity with age but showed no sex-linked differences.
6. The results suggest that kallikrein is sequestered in acinar cells whereas the androgen-dependent enzymes (chymotrypsin, trypsin and renin) are located in the secretory tubules.
88 citations
Patent•
02 Feb 1976TL;DR: New amino sugars which are glucopyranosyl and oligoglucosidyl derivatives of 4,6-bisdesoxy-4-(4,5-6-trihydroxy-3-hydroxymethylcyclohex-2-en-1-ylamino)-α-D-glucopyranose inhibit glycoside hydrolases of the digestive tract as discussed by the authors.
Abstract: New amino sugars which are glucopyranosyl and oligoglucosidyl derivatives of 4,6-bisdesoxy-4-(4,5,6-trihydroxy-3-hydroxymethylcyclohex-2-en-1-ylamino)-α-D-glucopyranose inhibit glycoside hydrolases of the digestive tract. The compounds, of which O-{4,6-bisdesoxy-4-[1S-(1,4,6/5)-4,5,6-trihydroxy-3-hydroxymethylcyclohex-2-en-1-ylamino]-α-D-glucopyranosyl}-(1→4)-O-α-D-glucopyranosyl-(1→4)-D-glucopyranose is a representative embodiment, demonstrate both saccharase and amylase inhibiting properties.
88 citations
TL;DR: The fact that AmyAΔ cannot bind or hydrolyze raw starch, demonstrating that the carboxyl-terminal repeating-unit domain of AmyA is required for raw-starch binding activity, is striking.
Abstract: Two constructs derived from the alpha-amylase gene (amyA) of Lactobacillus amylovorus were expressed in Lactobacillus plantarum, and their expression products were purified, characterized, and compared. These products correspond to the complete (AmyA) and truncated (AmyADelta) forms of alpha-amylase; AmyADelta lacks the 66-kDa carboxyl-terminal direct-repeating-unit region. AmyA and AmyADelta exhibit similar amylase activities towards a range of soluble substrates (amylose, amylopectin and alpha-cyclodextrin, and soluble starch). The specific activities of the enzymes towards soluble starch are similar, but the K(M) and V(max) values of AmyADelta were slightly higher than those of AmyA, whereas the thermal stability of AmyADelta was lower than that of AmyA. In contrast to AmyA, AmyADelta is unable to bind to beta-cyclodextrin and is only weakly active towards glycogen. More striking is the fact that AmyADelta cannot bind or hydrolyze raw starch, demonstrating that the carboxyl-terminal repeating-unit domain of AmyA is required for raw-starch binding activity.
88 citations