Inhibition of ascorbic acid-induced modifications in lens proteins by peptides

✍ Scribed by Mariana Argirova; Ognyan Argirov

• Book ID: 105360263
• Publisher: John Wiley and Sons
• Year: 2003
• Tongue: English
• Weight: 125 KB
• Volume: 9
• Category: Article
• ISSN: 1075-2617
• DOI: 10.1002/psc.451

✦ Synopsis

Abstract

The effects of three dipeptides L‐phenylalanyl‐glycine, glycyl‐L‐phenylalanine, and aspartame (L‐aspartyl‐L‐phenylalanine, methyl ester) as inhibitors of the ascorbic acid‐induced modifications in lens proteins were studied. Their efficiency was compared to that of two known inhibitors—aminoguanidine and carnosine. The tested dipeptides diminished protein carbonyl content by 32–58% and most moderated the formation of chromophores, as measured by the absorbency at 325 nm of the glycated proteins. The appearance of non‐tryptophan fluorescence (excitation 340 nm/emission 410 nm) was observed for proteins glycated with ascorbic acid. All of the dipeptides examined, as well as aminoguanidine, decreased this glycation‐related fluorescence. The potential inhibitors prevented the intensive formation of very high molecular weight aggregates. A competitive mechanism of their inhibitory effect was proposed, based on the reactivity of individual substances toward ascorbic acid. These findings indicate that they have a potential for use as alternatives for aminoguanidine as an anti‐glycation agent. Copyright © 2003 European Peptide Society and John Wiley & Sons, Ltd.