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A low‐molecular weight acid phosphatase present in crystalline preparations of rabbit skeletal muscle glycogen phosphorylase b
Author(s) -
Sotiroudis Theodore G.,
Geladopoulos Taxiarchis P.
Publication year - 1990
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(90)80375-s
Subject(s) - glycogen phosphorylase , sephadex , acid phosphatase , phosphorylase kinase , chemistry , biochemistry , enzyme , phosphatase , vanadate , phosphate , glycogen branching enzyme , glycogen , tartrate , alkaline phosphatase , size exclusion chromatography , chromatography
Crystalline preparations of glycogen phosphorylase b contain traces of acid phosphatase activity. Non‐denaturing gel electrophoresis of phosphorylase b reveals a single band of 1‐naphthyl phosphate phosphohydrolase activity which co‐migrates with phosphorylase. The two enzymes can be separated by Sephadex G‐200 column chromatography, where the phosphatase exhibits an apparent M r , of 17000. The contaminant enzyme hydrolyzes effectively the phenolic ester of monoorthophosphate with optimal activity for p ‐nitrophenyl phosphate and L‐phosphotyrosine between pH 5.5 and 6.0. The phosphatase is insensitive to inhibition by L(+)‐tartrate but strongly inhibited by μM vanadate and Zn 2+ .