Structure, binding interface and hydrophobic transitions of Ca2+-loaded calbindin-D(28K).

Journal Article (Journal Article)

Calbindin-D(28K) is a Ca2+-binding protein, performing roles as both a calcium buffer and calcium sensor. The NMR solution structure of Ca2+-loaded calbindin-D(28K) reveals a single, globular fold consisting of six distinct EF-hand subdomains, which coordinate Ca2+ in loops on EF1, EF3, EF4 and EF5. Target peptides from Ran-binding protein M and myo-inositol monophosphatase, along with a new target from procaspase-3, are shown to interact with the protein on a surface comprised of alpha5 (EF3), alpha8 (EF4) and the EF2-EF3 and EF4-EF5 loops. Fluorescence experiments reveal that calbindin-D(28K) adopts discrete hydrophobic states as it binds Ca2+. The structure, binding interface and hydrophobic characteristics of Ca2+-loaded calbindin-D(28K) provide the first detailed insights into how this essential protein may function. This structure is one of the largest high-resolution NMR structures and the largest monomeric EF-hand protein to be solved to date.

Full Text

Duke Authors

Cited Authors

  • Kojetin, DJ; Venters, RA; Kordys, DR; Thompson, RJ; Kumar, R; Cavanagh, J

Published Date

  • July 2006

Published In

Volume / Issue

  • 13 / 7

Start / End Page

  • 641 - 647

PubMed ID

  • 16799559

International Standard Serial Number (ISSN)

  • 1545-9993

Digital Object Identifier (DOI)

  • 10.1038/nsmb1112

Language

  • eng

Conference Location

  • United States