Structure and stability of the dityrosine-linked dimer of γB-crystallin

Kanwar, R. ; Balasubramanian, D. (1999) Structure and stability of the dityrosine-linked dimer of γB-crystallin Experimental Eye Research, 68 (6). pp. 773-784. ISSN 0014-4835

Full text not available from this repository.

Official URL:

Related URL:


Oxidative damage to proteins leads to a variety of modifications such as racemization, carbonyl compound formation, new fluorophores, aggregation, crosslinking and insolubility, several of which are markers of pathogenesis. A particular modification that has been associated with abnormal and pathological situations is the dityrosine crosslink in proteins, thought to be responsible for the reduced solubility and elasticity of proteins, and plaque formation. Dityrosine crosslinking has been suspected to occur in the crystallins of the eye lens during cataract. We focus attention here on the generation, structure and conformational stability of such a dityrosine-linked protein of the eye lens. We find this crosslink to be readily generated photodynamically in the presence of sensitizers. Among the crystallins, crosslinking occurs most readily in the γ-crystallins under these conditions. We have isolated, purified and studied the properties of the dityrosine-linked dimer of the eye lens protein γB-crystallin. While the dityrosine crosslink does not alter the secondary structure of the protein, it changes the tertiary structure in a subtle manner. This alteration destabilizes the dimer, which denatures more readily than the parent monomer, and also makes it precipitate more readily, a point of relevance to cataractogenesis of the eye lens. Comparison of these results with those reported on other dityrosine-dimerized proteins suggests that while the conformation of these proteins might not be altered in a major manner upon dityrosine linkage, the dimer is structurally less stable and displays reduced solubility, both of which are of pathological importance.

Item Type:Article
Source:Copyright of this article belongs to Elsevier Science.
Keywords:γB Crystallin; Dityrosine Crosslinks; Post-translational Modifications in Proteins; Conformational Analysis; Structural Stability
ID Code:1250
Deposited On:04 Oct 2010 08:01
Last Modified:13 May 2011 07:07

Repository Staff Only: item control page