Details

Autor(en) / Beteiligte

• Meissner, Gerhard
• Pasek, Daniel A.
• Yamaguchi, Naohiro
• Ramachandran, Srinivas
• Dokholyan, Nikolay V.
• Tripathy, Ashutosh

Titel

Thermodynamics of calmodulin binding to cardiac and skeletal muscle ryanodine receptor ion channels

Ist Teil von

• Proteins, structure, function, and bioinformatics, 2009-01, Vol.74 (1), p.207-211

Ort / Verlag

Hoboken: Wiley Subscription Services, Inc., A Wiley Company

Erscheinungsjahr

2009

Link zum Volltext

Quelle

MEDLINE

Beschreibungen/Notizen

• The skeletal muscle (RyR1) and cardiac muscle (RyR2) ryanodine receptor calcium release channels contain a single, conserved calmodulin (CaM) binding domain, yet are differentially regulated by CaM. Here, we report that high‐affinity [35S]CaM binding to RyR1 is driven by favorable enthalpic and entropic contributions at Ca2+ concentrations from <0.01 to 100 μM. At 0.15 μM Ca2+, [35S]CaM bound to RyR2 with decreased affinity and binding enthalpy compared with RyR1. The rates of [35S]CaM dissociation from RyR1 increased as the temperature was raised, whereas at 0.15 μM Ca2+ the rate from RyR2 was little affected. The results suggest major differences in the energetics of CaM binding to and dissociation from RyR1 and RyR2. Proteins 2009. © 2008 Wiley‐Liss, Inc.