Adenosine-5'-tetraphosphate and guanosine-5'-tetraphosphate: new substrates of the cytosolic exopolyphosphatase of the yeast Saccharomyces cerevisiae.

T V Kulakovskaya, N A Andreeva, I S Kulaev

Index: Biochemistry. (Mosc.) 62 , 1051-1052, (1997)

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Abstract

A cytosolic preparation of Saccharomyces cerevisiae is capable of hydrolyzing adenosine-5'-tetraphosphate and guanosine-5'-tetraphosphate with activities which are 1.5-2 times greater than that with polyP15. The apparent K(m) values for hydrolysis of adenosine-5'-tetraphosphate and guanosine-5'-tetraphosphate are 100 and 80 microM, respectively. A comparative study of inhibitors shows that these activities are inherent characteristics of these exopolyphosphatases.