Dephosphorylation of bovine casein by milk alkaline phosphatase
The pH of optimum activity of alkaline phosphatase from cow's milk depended on the substrate, being 10-1 for rho-nitrophenylphosphate, 8-6 for phosphoserine, 8-0 for phosvitin and 6-8 for casein. Individual casein components were dephosphorylated more rapidly than mixtures of alphas- and beta-c...
Saved in:
Published in | Journal of dairy research Vol. 43; no. 1; p. 19 |
---|---|
Main Authors | , |
Format | Journal Article |
Language | English |
Published |
England
01.02.1976
|
Subjects | |
Online Access | Get more information |
Cover
Loading…
Summary: | The pH of optimum activity of alkaline phosphatase from cow's milk depended on the substrate, being 10-1 for rho-nitrophenylphosphate, 8-6 for phosphoserine, 8-0 for phosvitin and 6-8 for casein. Individual casein components were dephosphorylated more rapidly than mixtures of alphas- and beta-caseins or of alphas-, beta-and kappa-caseins and micellar casein. Mixtures of 2 components involving kappa-casein were more readily dephosphorylated than alphas- and beta-casein mixtures. At pH 6-8, lactose, whey proteins and phosphate ions had an inhibitory effect. beta-Lactoglobulin had an inhibitory effect only when the pH of the reaction was lower than the optimum pH value of the enzyme. Mg2+ and Zn2+ were not inhibitory. The optimum conditions for dephosphorylation of casein are described. |
---|---|
ISSN: | 0022-0299 |
DOI: | 10.1017/S0022029900015557 |