| Literature DB >> 2931121 |
R Dabrowska, A Goch, B Gałazkiewicz, H Osińska.
Abstract
Chicken gizzard caldesmon causes up to 40% inhibition of Mg2+-ATPase activity of rabbit skeletal muscle actomyosin. In the presence of chicken gizzard tropomyosin this inhibition is significantly increased, reaching a maximum (around 80%) at a molar ratio of caldesmon to actin monomer of 1 to 10-13. The inhibition of actomyosin ATPase takes place over a wide pH range (from 6.0 to 8.0) but is decreased with an increase in KCl and MgCl2 concentrations. Caldesmon, in the range of caldesmon/ actin ratios within which it inhibits actomyosin ATPase, forms bundles of parallelly aligned actin filaments. Calmodulin in the presence of Ca2+ dissociates these bundles and restrains the inhibition of actomyosin ATPase, provided that it is used at a high molar excess over caldesmon.Entities:
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Year: 1985 PMID： 2931121 DOI： 10.1016/0304-4165(85)90295-8
Source DB: PubMed Journal: Biochim Biophys Acta ISSN： 0006-3002