title: Site-specific racemization in aging alpha A-crystallin.
abstract: Of all aspartyl residues in bovine alpha A-crystallin, only Asp-151 exhibits pronounced racemization. Asp-151 is also one of the sites where peptide bond cleavage occurs in in vivo aging alpha A-crystallin. This aspartyl residue is followed by an alanyl residue and resides in a flexible carboxyl terminal extension of alpha-crystallin. Both in vivo and in vitro racemization studies indicate that the pronounced and site-specific racemization of Asp-151 proceeds via formation of a succinimide intermediate. The in vivo racemization of aspartyl residues in alpha A-crystallin is discussed with regard to the proposed tertiary structure of alpha-crystallin.
authors.affiliation: Department of Biochemistry, University of Nijmegen, The Netherlands.
authors.forename: P J
authors.initials: PJ
authors.lastname: Groenen
authors.forename: P R
authors.initials: PR
authors.lastname: van den Ijssel
authors.forename: C E
authors.initials: CE
authors.lastname: Voorter
authors.forename: H
authors.initials: H
authors.lastname: Bloemendal
authors.forename: W W
authors.initials: WW
authors.lastname: de Jong
mesh_terms: D000375:Aging; D000595:Amino Acid Sequence; D000818:Animals; D001224:Aspartic Acid; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D003459:Crystallins; D008969:Molecular Sequence Data; D013237:Stereoisomerism; D013388:Succinimides
chemical_list: D003459:Crystallins; D013388:Succinimides; D001224:Aspartic Acid