ζ‐Crystallin versus other members of the alcohol dehydrogenase super‐family Variability as a functional characteristic

FEBS Letters

Zigler, J.Samuel⁴  Rao, P.Vasantha⁴  Chen, John H.³  Gonzalez, Pedro⁴  Persson, Bengt²  Lavers, Gene C.³  Du Bois, Garrett C.¹  Jörnvall, Hans² 

[1] Department of Pharmacology, Jefferson Cancer Institute, 233 South 10th Street, Philadelphia, PA 19107, USA;Department of Chemistry I, Karolinska Institutet, S-104 01, Stockholm, Sweden;Division of Basic Sciences — Biochemistry, New York University Dental Center, 345 East 24th Street, New York, NY 10010, USA;Laboratory of Mechanisms of Ocular Diseases, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA

关键词: Crystallin;    Alcohol dehydrogenase;    Structure—function relationship;    Segment variability;    Glycine conservation;   

DOI  :  10.1016/0014-5793(93)81578-N

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Species variability of the lens protein ζ-crystallin was correlated with those of alcohol dehydrogenases of classes I and III and sorbitol dehydrogenase in the same protein family. The extent of overall variability, nature of residues conserved, and patterns of segment variability, all fall within the limits typical of the ‘variable’ group of medium-chain alcohol dehydrogenases. This shows that ζ-crystallin is subject to restrictions similar to those of classical liver alcohol dehydrogenase and therefore derived from a metabolically active enzyme like other enzyme crystalline. Special residues at the active site, however, differ substantially, including an apparent lack of a zinc-binding site. This is compatible with altered functional properties and makes the spread within this medium-chain dehydrogenase family resemble the wide spread within the short-chain dehydrogenases. Schematic plotting is useful for illustrating the differences between ‘variable’ and ‘constant’ enzymes.

【 授权许可】

Unknown