Abstract
Although it has been known for many years that opacification of the human lens is accompanied by oxidation of cysteine sulfhydryl groups to half-cystine residues, nothing is known concerning the exact amino acid sequences involved in this oxidative process. Since alpha-A crystallin is one of the major proteins of the lens, and since a decrease in its molecular chaperone activity has been implicated in possible mechanisms of cataract formation, alpha-A crystallin was purified from total lens proteins by reverse phase chromatography, followed by digestion with lys-C endoprotease. Mass spectral analysis of the digest indicated that in normal transparent lenses, cys-131 and cys-142 from alpha-A crystallin are present as a mixture of cysteine sulfhydryl and half-cystine disulfide groups, while identical analysis from cataractous lenses demonstrated undetectable levels of the cysteine sulfhydryl group. Together, these results demonstrate for the first time, the involvement of specific cysteine residues in the oxidative mechanism of human lens opacification.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Biochemical and Biophysical Research Communications
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
