Human pancreatic alpha-amylase. II. Effects of pH, substrate and ions on the activity of the enzyme.
نویسندگان
چکیده
Purified human pancreatic alpha-amylase (alpha-1,4-glucan 4-glucano-hydrolase, EC 3.2.1.1) was found to be stable over a wide range of pH values (5.0 to 10.5) with an optimal pH for the enzymatic activity of 7.0. The Michaelis constant of the enzyme at optimal pH and assay conditions was found to be 2.51 mg per ml for soluble starch. Halide ions were required for the activity of the enzyme whereas sulfate and nitrate were not. The order of effectiveness of activation was found to be: Cl- greater than Br- greater than I- greater than F-. Calcium and magnesium were activators at concentrations of 0.001M and 0.005M, respectively, but exhibited inhibitory effects at concentrations higher than 0.005M. At 0.01M ethylenediamine tetraacetic acid (EDTA) concentration the enzymatic activity upon seven min incubation, was inhibited up to 96%. The inhibition of EDTA and calcium could be reversed upon addition of calcium and EDTA, respectively.
منابع مشابه
Investigation of pancreatic digestive enzymes changes from egg to larvae phase of Schizothorax zarudnyi
In order to identify trends and provide suitable diet for Schizothorax zarudnyi, the activity of alpha-amylase, trypsin, and lipase in five treatment groups including: fertilized egg, newly-hatched larvae, the larvae a day, larvae absorbed in the bag 2/ 3 yolk and absorption of yolk sac larvae, in 20 embryonated eggs and 80 larvae at the end of 53 days were studied. Analysis of the data showed ...
متن کاملHypoglycemic activity of Pyrus biossieriana Buhse leaf extract and arbutin: Inhibitory effects on alpha amylase and alpha glucosidase
Background: The mechanism of hypoglycemic and hypolipidemic activities of Pyrus biossieriana Buhse leaf extract (PbBLE) and its phytochemical component arbutin, have not been well determined. The present study was performed to understand the hypoglycemic activity mechanisms of pbBLE and arbutin more clearly.Methods: In vitro enzymatic carbohydrate digestion with PbBLE and arbutin was assessed u...
متن کاملEvaluation of alpha- amylase inhibition by Urtica dioica and Juglans regia extracts
Objective(s):One strategy for the treatment of diabetes is inhibition of pancreatic α- amylase. Plants contains different chemical constituents with potential for inhibition of α-amylase and hence maybe used as therapeutic. Materials and Methods: Urtica dioica and Juglans regia Linn were tested for α-amylase inhibition. Different concentrations of leaf aqueous extracts were incubated with enzym...
متن کاملAmylase inhibitory activity of some macrolichens in Mazandaran province, Iran
Introduction: α-amylase is a major form of amylase found in humans and other mammals. It is the special key enzyme involved in carbohydrates breakdown. Inhibition of this enzyme could be used in treatment of diabetes. In this study, the effect of ten Iranian macrolichens on alpha amylase were tested. Methods: Different concentrations of the extracts (25, 50 and 75 mg/ml) were incubated wi...
متن کاملBacillus Amyloliquefaciens Alpha-amylase Inhibition by Organic Solvents: A Study on Methanol, Ethanol and Propanol
Alpha-amylase is widely used as an industrial enzyme, and a therapeutic target for which inhibitors are designed. Organic solvents are used to dissolve various compounds that would be studied as moderators of alpha-amylases, but they could themselves affect enzyme activity and stability. Methanol, ethanol and propanol are simple alcohols that may be commonly used to this end, and their effect h...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Annals of clinical and laboratory science
دوره 7 4 شماره
صفحات -
تاریخ انتشار 1977