Affordable Access

Studies of ligand binding to arrestin.

Authors
Type
Published Article
Journal
Journal of Biological Chemistry
0021-9258
Publisher
American Society for Biochemistry and Molecular Biology
Publication Date
Volume
266
Issue
7
Pages
4201–4206
Identifiers
PMID: 1999413
Source
Medline

Abstract

A striking homology is observed between the regions 70-83 and 361-374 of the sequence of bovine arrestin and the calcium-binding loops of calmodulin and troponin C. However, the predicted alpha-helices flanking the calcium-binding site in calmodulin and troponin C are not present in arrestin. Direct measurements therefore were made in order to assess whether arrestin can bind calcium. We found that arrestin does not bind Ca2+ at physiological ionic strength, as determined by equilibrium dialysis, gel filtration, and fluorescence spectroscopy. Rapid and quantitative precipitation of arrestin occurs with Tb3+. The precipitation is reversed by EDTA and blocked by Mg2+ but not by Ca2+. Prompted by several reports, we also investigated whether nucleotides bind to arrestin. Neither ATP nor GTP binds under the conditions tested. Binding of arrestin to photolyzed, phosphorylated rhodopsin also does not influence the binding of calcium or nucleotides.

There are no comments yet on this publication. Be the first to share your thoughts.

Statistics

Seen <100 times
0 Comments
F