Kinetics of isomerization and inversion of aspartate 58 of αA-crystallin peptide mimics under physiological conditions.

ABSTRACT: Although proteins consist exclusively of L-amino acids, we have reported that aspartyl (Asp) 58 and Asp 151 residues of αA-crystallin of eye lenses from elderly cataract donors are highly inverted and isomerized to D-β, D-α and L-β-Asp residues through succinimide intermediates. Of these Asp isomers, large amounts of D-β- and L-β-isomers are present but the amount of D-α-isomer is not significant. The difference in abundance of the Asp isomers in the protein may be due to the rate constants for the formation of the isomers. However, the kinetics have not been well defined. Therefore, in this study, we synthesized a peptide corresponding to human αA-crystallin residues 55 to 65 (T(55)VLD(58)SGISEVR(65)) and its isomers in which L-α-Asp at position 58 was replaced with L-β-, D-β- and D-α-Asp

SUBMITTER: Aki K 

PROVIDER: S-EPMC3591338 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature