A low-molecular weight acid phosphatase present in crystalline preparations of rabbit skeletal muscle glycogen phosphorylase b.
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 Mr of 17,000. 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 microM vanadate and Zn2+.
Institute of Biological Research, National Hellenic Research Foundation, Athens, Greece.
T G
TG
Sotiroudis
T P
TP
Geladopoulos
D000135:Acid Phosphatase / Q000378:metabolism*; D000818:Animals; D002850:Chromatography, Gel; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008970:Molecular Weight; D009132:Muscles / Q000187:drug effects / Q000201:enzymology*; D009596:Nitrophenols / Q000378:metabolism; D009943:Organophosphorus Compounds / Q000378:metabolism; D010763:Phosphorylase b / Q000378:metabolism*; D019000:Phosphotyrosine; D011817:Rabbits; D013379:Substrate Specificity; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism; D014638:Vanadates / Q000494:pharmacology; D015032:Zinc / Q000494:pharmacology
D009596:Nitrophenols; D009943:Organophosphorus Compounds; D019000:Phosphotyrosine; C008644:nitrophenylphosphate; D014638:Vanadates; D014443:Tyrosine; D010763:Phosphorylase b; D000135:Acid Phosphatase; D015032:Zinc