STUDIES ON ATP DEAMINASE

[摘要] To clarify the relationship between the substrate structure and enzyme activity, substrate specificity of ATP deaminase from Microsporum audouini was examined in detail, in using 35 kinds of adenine compounds. 5′-ATP, 5′-ATPP, 5′-ADP, 5′-Ad-sulfate, 5′-ADP-ribose, 5′-AMP and 5′-ADP-glucose were rapidly deaminated in this order. Adenosine was deaminated at a slow rate, but adenine was not deaminated. This enzyme also catalyzed the deamination of 3-iso-AMP and the dechlorination of 6-chloropurine riboside. The C′-1 or C′-2 position of ribose is necessary for binding to the enzyme, and the negatively charged group such as phosphate or sulfate at the 5′-position of ribose is most essential for the effective deamination. A probable schematic model showing the relationship between this enzyme and substrate was presented.

[学科分类] 微生物学和免疫学