Covalent binding of tea catechins to protein thiols: The relationship between stability and electrophilic reactivity

Taiki Mori, Takeshi Ishii, Mitsugu Akagawa, Yoshimasa Nakamura, Tsutomu Nakayama

Research output: Contribution to journalArticle

40 Citations (Scopus)

Abstract

In this study, we investigated the relationship between the stability of catechins and their electrophilic reactivity with proteins. The stability of catechins was evaluated by HPLC analysis. Catechol-type catechins were stable in a neutral buffer, but pyrogallol-type catechins, such as (-)-epigallocatechin gallate (EGCg), were unstable. The electrophilic reactivity of catechins with thiol groups in a model peptide and a protein was confirmed by both mass spectrometry and electrophoresis/ blotting with redox-cycling staining. In a comparison of several catechins, pyrogallol-type catechins had higher reactivity with protein thiols than catechol-type catechins. The instability and reactivity of EGCg were enhanced in an alkaline pH buffer. The reactivity of EGCg was reduced by antioxidants due to their ability to prevent EGCg autoxidation. These results indicate that the instability against oxidation of catechins isprofoundly related to their electrophilic reactivity. Consequently, the difference in these properties of tea catechins can contribute to the magnitude of their biological activities.

Original languageEnglish
Pages (from-to)2451-2456
Number of pages6
JournalBioscience, Biotechnology and Biochemistry
Volume74
Issue number12
DOIs
Publication statusPublished - Dec 1 2010

Keywords

  • Electrophile
  • Polyphenol
  • Protein thiols
  • Stability
  • Tea catechin

ASJC Scopus subject areas

  • Biotechnology
  • Analytical Chemistry
  • Biochemistry
  • Applied Microbiology and Biotechnology
  • Molecular Biology
  • Organic Chemistry

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