Kovina M V, Tikhonova O V, Solov'eva O N, Bykova I A, Ivanov A S, Kochetov G A
A. N. Belozersky Institute of Physico-Chemical Biology, Moscow, 119899, Russia.
Biochem Biophys Res Commun. 2000 Sep 7;275(3):968-72. doi: 10.1006/bbrc.2000.3412.
Dynamics stimulation of the holotransketolase molecule revealed that the enzyme's conformation in crystal was different from that in solution. It was shown also that dissolved holotransketolase can bind aldose (the acceptor substrate) even in the absence of ketose (the donor substrate). The holotransketolase conformation did not change upon aldose binding unlike in the case of ketose binding/cleavage. Therefore the conformation of a catalytic complex of holotransketolase with an intermediate-i.e., a glycolaldehyde residue formed upon binding and subsequent cleavage of ketose-differed, at least in solution, from the conformation of both the free and aldose-complexed holotransketolase. Some structural peculiarities of the holotransketolase with the intermediate were established by means of molecular dynamics stimulation.
对全转酮醇酶分子的动力学刺激表明，该酶在晶体中的构象与在溶液中的构象不同。还表明，即使在没有酮糖（供体底物）的情况下，溶解的全转酮醇酶也能结合醛糖（受体底物）。与酮糖结合/裂解的情况不同，醛糖结合后全转酮醇酶的构象没有变化。因此，全转酮醇酶与中间体（即酮糖结合并随后裂解时形成的乙醇醛残基）的催化复合物的构象，至少在溶液中，与游离的和醛糖复合的全转酮醇酶的构象不同。通过分子动力学刺激确定了全转酮醇酶与中间体的一些结构特性。
