ISOLATION AND CHARACTERIZATION OF AN ACID-PHOSPHATASE INTERFERING WITH PHOSPHORYLASE DETERMINATIONS IN CRUDE EXTRACTS FROM YEAST

被引:3
作者
BECKER, JU
机构
[1] Botanisches Institut der Universität Bonn, Bonn 1, D-5300
关键词
Glucose-1-phosphate; Hydrolysis by yeast phosphatase; Phosphatase acid from yeast; Yeast phosphatase; acid; isolation; separation from phosphorylase; Yeast phosphorylase; interference by acid phosphatase;
D O I
10.1007/BF00406655
中图分类号
Q93 [微生物学];
学科分类号
071005 ; 100705 ;
摘要
In phosphorylase assays in crude yeast extracts with glucose-1-phosphate (G-1-P) as substrate, 25-30% of the Pi-liberating activity could not be inhibited by antibodies against yeast phosphorylase and were attributed to the action of phosphatases. During phosphorylase preparation from baker's yeast (Saccharomyces cerevisiae), a phosphatase, molecular weight 45000±5000, with high specificity for G-1-P, pH-optimum 5.6, was isolated which appeared to be responsible for the interference. It did not hydrolyze other glycolytic intermediates, pyrophosphate or adenylates. No activation by Mg2+ or inhibition by (+)-tartrate, and only 40% inhibition by 50 mM F- were observed, 5,5′ dithiobis-(nitrobenzoic acid) (10mM) inactivated the enzyme completely. Its affinity for G-1-P was very low (Km=40 mM). Consequently, it mainly interfered with the phosphorylase assay in the amylose synthesizing reaction, in which high G-1-P-concentrations have to be used. For phosphorylase assays in crude extracts, measurement of the phosphorolytic activity is recommended, in which the concentration of G-1-P is kept sufficiently low. © 1979 Springer-Verlag.
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页码:233 / 238
页数:6
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