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B-factor Analysis and Conformational Rearrangement of Aldose Reductase.

ABSTRACT: The NADPH-dependent reduction of glucose reaction that is catalyzed by Aldose Reductase (AR) follows a sequential ordered kinetic mechanism in which the co-factor NADPH binds to the enzyme prior to the aldehyde substrate. The kinetic/structural experiments have found a conformational change involving a hinge-like movement of a surface loop (residues 213-224) which is anticipated to take place upon the binding of the diphosphate moiety of NADPH. The reorientation of this loop, expected to permit the release of NADP+, represents the rate-limiting step of the catalytic mechanism. This study reveals: 1) The Translation/Libration/Screw (TLS) analysis of absolute B-factors of apo AR crystal structures indicates that the 212-224 loop might move as a rigid group. 2) Residues that make the flexible loop slide in the AR binary and ternary complexes. 3) The normalized B-factors separate this segment into three different clusters with fewer residues.

SUBMITTER: Balendiran GK

PROVIDER: S-EPMC4212266 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature

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B-factor Analysis and Conformational Rearrangement of Aldose Reductase.

Balendiran Ganesaratnam K GK Pandian J Rajendran JR Drake Evin E Vinayak Anubhav A Verma Malkhey M Cascio Duilio D

Current proteomics 20140101 3

The NADPH-dependent reduction of glucose reaction that is catalyzed by Aldose Reductase (AR) follows a sequential ordered kinetic mechanism in which the co-factor NADPH binds to the enzyme prior to the aldehyde substrate. The kinetic/structural experiments have found a conformational change involving a hinge-like movement of a surface loop (residues 213-224) which is anticipated to take place upon the binding of the diphosphate moiety of NADPH. The reorientation of this loop, expected to permit ...[more]

PMID: 25364319

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