The effects of Ca2+ binding on the conformation of calbindin D28K: A nuclear magnetic resonance and microelectrospray mass spectrometry study

Ronald A. Venters, Linda M. Benson, Theodore A. Craig, Keriann H. Paul, David R. Kordys, Richele Thompson, Stephen Naylor, Rajiv Kumar, John Cavanagh

Research output: Contribution to journalArticle

20 Scopus citations

Abstract

Calbindin D28K is a six-EF-hand calcium-binding protein found in the brain, peripheral nervous system, kidney, and intestine. There is a paucity of information on the effects of calcium binding on calbindin D28K structure. To further examine the mechanism and structural consequences of calcium binding to calbindin D28K we performed detailed complementary heteronuclear NMR and microelectrospray mass spectrometry investigations of the calcium-induced conformational changes of calbindin D28K. The combined use of these two powerful analytical techniques clearly and very rapidly demonstrates the following: (i) apo-calbindin D28K has an ordered structure which changes to a notably different ordered conformation upon Ca2+ loading, (ii) calcium binding is a sequential process and not a simultaneous event, and (iii) EF-hands 1, 3, 4, and 5 take up Ca2+, whereas EF-hands 2 and 6 do not. Our results support the opinion that calbindin D28K has characteristics of both a calcium sensor and a buffer.

Original languageEnglish (US)
Pages (from-to)59-66
Number of pages8
JournalAnalytical Biochemistry
Volume317
Issue number1
DOIs
StatePublished - Jun 1 2003

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Keywords

  • Calbindin D
  • Conformational response to calcium binding
  • EF-Hand

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology

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