Substrate specificity of uridine and purine nucleoside phosphorylases of the whole cells of Escherichia coli |
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| Authors: | A I Zintchenko L A Eroshevskaya V N Barai I A Mikhailopulo |
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| Affiliation: | Institute of Microbiology, Byelorussian SSR Academy of Sciences, Minsk. |
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| Abstract: | Substrate specificity of uridine and purine nucleoside phosphorylases of the whole cells of Escherichia coli BM-11 has been studied. Both enzymes reveal similar requirements to the structure and stereochemistry of uracil nucleosides and of the pentofuranose-1-phosphates, respectively, viz, a) modifications at C-3' decreased the substrate activity to a greater extent as compared with the same modifications at C-2'; b) substitution of a methyl group for one of the 5'-CH2 protons does not lead to essential alterations of the substrate activity of such analogs vs. the natural substrates - uridine and ribofuranose-1-phosphate, respectively. PNP exhibits a very broad specificity for the purine acceptor. |
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