Specifically targeted modification of human aldose reductase by physiological disulfides

Mario Cappiello, Margaret Voltarelli, Ilaria Cecconi, Pier Giuseppe Vilardo, Massimo Dal Monte, Isabella Marini, Antonella Del Corso, David K. Wilson, Florante A. Quiocho, J. Mark Petrash, Umberto Mura

Research output: Contribution to journalArticlepeer-review

66 Scopus citations


Aldose reductase is inactivated by physiological disulfides such as GSSG and cystine. To study the mechanism of disulfide-induced enzyme inactivation, we examined the rate and extent of enzyme inactivation using wild-type human aldose reductase and mutants containing cysteine-to-serine substitutions at positions 80 (C80S), 298 (C298S), and 303 (C303S). The wild-type, C80S, and C303S enzymes lost >80% activity following incubation with GSSG, whereas the C298S mutant was not affected. Loss of activity correlated with enzyme thiolation. The binary enzyme-NADP + complex was less susceptible to enzyme thiolation than the apoenzyme. These results suggest that thiolation of human aldose reductase occurs predominantly at Cys-298. Energy minimization of a hypothetical enzyme complex modified by glutathione at Cys-298 revealed that the glycyl carboxylate of glutathione may participate in a charged interaction with His-110 in a manner strikingly similar to that involving the carboxylate group of the potent aldose reductase inhibitor Zopolrestat. In contrast to what was observed with GSSG and cystine, cystamine inactivated the wild-type enzyme as well as all three cysteine mutants. This suggests that cystamine-induced inactivation of aldose reductase does not involve modification of cysteines exclusively at position 80, 298, or 303.

Original languageEnglish (US)
Pages (from-to)33539-33544
Number of pages6
JournalJournal of Biological Chemistry
Issue number52
StatePublished - 1996
Externally publishedYes

ASJC Scopus subject areas

  • Biochemistry


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