Structural studies of the N-terminus of Connexin 32 using 1H NMR spectroscopy

B. D. Kalmatsky, S. Bhagan, Q. Tang, T. A. Bargiello, T. L. Dowd

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

The amino terminus of gap junction proteins, connexins, plays a fundamental role in voltage gating and ion permeation. We have previously shown with 1H NMR that the structure of the N-terminus of a representative connexin molecule contains a flexible turn around glycine 12 [P.E. Purnick, D.C. Benjamin, V.K. Verselis, T.A. Bargiello, T.L. Dowd, Arch. Biochem. Biophys. 381 (2000) 181-190] allowing the N-terminus to reside at the cytoplasmic entry of the channel forming a voltage-sensor. Previous functional studies or neuropathies have shown that the mutation G12Y and G12S form non-functional channels while functional channels are formed from G12P. Using 2D 1H NMR we show that similar to G12, the structure of the G12P mutant contains a more flexible turn around residue 12, whereas the G12S and G12Y mutants contain tighter, helical turns in this region. These results suggest an unconstrained turn is required around residue 12 to position the N-terminus within the pore allowing the formation of the cytoplasmic channel vestibule, which appears to be critical for proper channel function.

Original languageEnglish (US)
Pages (from-to)9-16
Number of pages8
JournalArchives of Biochemistry and Biophysics
Volume490
Issue number1
DOIs
StatePublished - Oct 1 2009

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Connexins
Nuclear magnetic resonance spectroscopy
Magnetic Resonance Spectroscopy
Nuclear magnetic resonance
Electric potential
Arches
Permeation
Glycine
Ions
Mutation
Molecules
Sensors
connexin 32
Proton Magnetic Resonance Spectroscopy

Keywords

  • Atomic resolution structure
  • Connexins
  • Ion channels
  • NMR
  • Protein structure and function
  • Structure-function
  • Voltage dependent gating

ASJC Scopus subject areas

  • Biochemistry
  • Biophysics
  • Molecular Biology

Cite this

Structural studies of the N-terminus of Connexin 32 using 1H NMR spectroscopy. / Kalmatsky, B. D.; Bhagan, S.; Tang, Q.; Bargiello, T. A.; Dowd, T. L.

In: Archives of Biochemistry and Biophysics, Vol. 490, No. 1, 01.10.2009, p. 9-16.

Research output: Contribution to journalArticle

Kalmatsky, B. D. ; Bhagan, S. ; Tang, Q. ; Bargiello, T. A. ; Dowd, T. L. / Structural studies of the N-terminus of Connexin 32 using 1H NMR spectroscopy. In: Archives of Biochemistry and Biophysics. 2009 ; Vol. 490, No. 1. pp. 9-16.
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