Регуляторная роль транскетолазы и некоторых метаболитов пентозофосфатного пути в синтезе фосфорибозилпирофосфата гемолизатами эритроцитов

The influence of metabolites of pentose phosphate pathway such as ribose-5-phosphate, an equilibrium mix of pentose phosphates (ribose-5-phosphate, xylulose-5-phosphate, ribulose-5-phosphate), glucose-6-phosphate, as well as ATP and Р. on the synthesis ofphosphoribosylpyrophosphate in erythrocyte hemolysates of rats was investigated. It is shown, that phosphoribosylpyrophosphate synthetase of erythrocytes is highly sensitive to the changes in concentration of ribose-5-phosphate (K =0,18mM, ATP-K= 0,36mM), pentose phosphates, glucose-6-phosphathe, as well as of Р.. The addition of a puritied transketolase to hemolysate erythrocytes is accompanied by the significant blocking of phosphoribosylpyrophosphate biosynthesis. The effect of transketolase is supposed to be due to its influence on pentose phosphates concentration. The role of the products of transketolase reactions, operating as inhibitors of phosphoribosylpirophosphate synthetase is not excluded as well.