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PROPERTIES OF RAT BRAIN NAD‐KINASE
Author(s) -
Fernandes M
Publication year - 1970
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1970.tb00528.x
Subject(s) - nad+ kinase , enzyme , acetone , biochemistry , tris , chemistry , stereochemistry
— NAD‐kinase was purified from rat brain acetone powder according to the method of W ang and K aplan (1954). The acetate buffer supernatant showed only very low specific activity but was largely free of the factors that interfere with the enzyme assay. The Michaelis constants for both substrates were determined, the values were 0·5 m m for NAD and 4·0 m m for ATP. The optimal pH was 7·4 in tris‐HCl buffer and the highest NAD‐kinase activity was observed in the hyaloplasm fraction. NADH 2 inhibited the enzyme whereas NADPH 2 did not. Finally, the reversible inhibition of SH‐binding compounds is described and the observed properties of rat brain NAD‐kinase compared with the properties of NADP synthesizing enzymes from pigeon liver and rat liver.