2f33

Publication Abstract from PubMed

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.

Structure, binding interface and hydrophobic transitions of Ca2+-loaded calbindin-D(28K).,Kojetin DJ, Venters RA, Kordys DR, Thompson RJ, Kumar R, Cavanagh J Nat Struct Mol Biol. 2006 Jul;13(7):641-7. Epub 2006 Jun 25. PMID:16799559^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.