| Structural differences in the two calcium binding sites of the porcine intestinal calcium binding protein: a multinuclear NMR study. | |
| | |
MedLine Citation:
|
PMID: 4052373 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Cadmium-113 and calcium-43 NMR spectra of Cd2+ and Ca2+ bound to the porcine intestinal calcium binding protein (ICaBP; Mr 9000) contain two resonances. The first resonance is characterized by NMR parameters resembling those found for these cations bound to proteins containing the typical helix-loop-helix calcium binding domains of parvalbumin, calmodulin, and troponin C, which are defined as EF-hands by Kretsinger [Kretsinger, R. H. (1976) Annu. Rev. Biochem. 45, 239]. The second resonance in both spectra has a unique chemical shift and is consequently assigned to the metal ion bound in the N-terminal site of ICaBP. This site is characterized by an insertion of a proline in the loop of the helix-loop-helix domain and will be called the pseudo-EF-hand site. The binding of Cd2+ to the apo form of ICaBP is sequential. The EF-hand site is filled first. Both binding sites have similar, but not identical, affinities for Ca2+: at a Ca2+ to protein ratio of 1:1, 65% of the ion is bound in the EF-hand site and 35% in the pseudo-EF-hand site. The two sites do not appear to act independently; thus, replacement of Ca2+ or Cd2+ by La3+ in the EF-hand site causes changes in the environment of the ions in the pseudo-EF-hand site. In addition, the chemical shift of Cd2+ bound to the EF-hand site is dependent on the presence or absence of Ca2+ or Cd2+ in the pseudo-EF-hand site.(ABSTRACT TRUNCATED AT 250 WORDS) |
| | |
Authors:
|
H J Vogel; T Drakenberg; S Forsén; J D O'Neil; T Hofmann |
Related Documents
:
|
23249163 - Dynamic factors affecting gaseous ligand binding in an artificial oxygen transport prot... 11902843 - A structural basis for s100 protein specificity derived from comparative analysis of ap... 16535863 - Discoveries of tat-tar interaction inhibitors for hiv-1. |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
|
Title: Biochemistry Volume: 24 ISSN: 0006-2960 ISO Abbreviation: Biochemistry Publication Date: 1985 Jul |
Date Detail:
|
Created Date: 1985-12-05 Completed Date: 1985-12-05 Revised Date: 2006-11-15 |
Medline Journal Info:
|
Nlm Unique ID: 0370623 Medline TA: Biochemistry Country: UNITED STATES |
Other Details:
|
Languages: eng Pagination: 3870-6 Citation Subset: IM |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Animals Binding Sites Calcium / metabolism* Calcium-Binding Proteins / metabolism* Cations, Divalent Duodenum / metabolism* Ileum / metabolism* Intestinal Mucosa / metabolism* Magnetic Resonance Spectroscopy / methods Protein Binding Protein Conformation Swine |
| Chemical | |
Reg. No./Substance:
|
0/Calcium-Binding Proteins; 0/Cations, Divalent; 7440-70-2/Calcium |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Light-scattering investigation of the dissociation behavior of Lunatia heros and Littorina littorea ...
Next Document: Prothrombin biosynthesis: characterization of processing events in rat liver microsomes.