Nonequivalence of transketolase active centers with respect to acceptor substrate binding.
The interaction of transketolase with its acceptor substrate, ribose 5-phosphate, has been studied. The active centers of the enzyme were shown to be functionally nonequivalent with respect to ribose 5-phosphate binding. Under the conditions where only one out of the two active centers of transketolase is functional, their affinities for ribose 5-phosphate are identical. The phenomenon of nonequivalence becomes apparent when the substrate interacts with one of the two active centers. As a consequence of such interaction, the affinity of the second active center for ribose 5-phosphate decreases.
A.N.Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia.
Vladimir A
VA
Yurshev
Irina A
IA
Sevostyanova
Olga N
ON
Solovjeva
Svetlana V
SV
Zabrodskaya
German A
GA
Kochetov
D001665:Binding Sites; D012267:Ribosemonophosphates / Q000378:metabolism*; D014174:Transketolase / Q000737:chemistry* / Q000378:metabolism
D012267:Ribosemonophosphates; C031626:ribose-5-phosphate; D014174:Transketolase