pH-dependent intramolecular binding and structure involving Cx43 cytoplasmic domains

Heather S. Duffy, Paul L. Sorgen, Mark E. Girvin, Phyllis O'Donnell, Wanda Coombs, Steven M. Taffet, Mario Delmar, David C. Spray

Research output: Contribution to journalArticle

137 Scopus citations


pH-induced closure of connexin43 (Cx43) channels involves interaction of the Cx43 carboxyl-terminal (Cx43CT) with a separate "receptor" domain. The receptor location and structure and whether the interaction is directly intramolecular are unknown. Here we show resonant mirror technology, enzyme-linked sorbent assays, and nuclear magnetic resonance (NMR) experiments demonstrating pH-dependent binding of Cx43CT to region 119-144 of Cx43 (Cx43L2), which we propose is the receptor. NMR showed that acidification induced α-helical order in Cx43L2, whereas only a minor modification in Cx43CT structure was detected. These data provide the first demonstration of chemically induced structural order and binding between cytoplasmic connexin domains.

Original languageEnglish (US)
Pages (from-to)36706-36714
Number of pages9
JournalJournal of Biological Chemistry
Issue number39
Publication statusPublished - Sep 27 2002


ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Cite this

Duffy, H. S., Sorgen, P. L., Girvin, M. E., O'Donnell, P., Coombs, W., Taffet, S. M., ... Spray, D. C. (2002). pH-dependent intramolecular binding and structure involving Cx43 cytoplasmic domains. Journal of Biological Chemistry, 277(39), 36706-36714.