Conformational changes of actin induced by calponin.
Calponin, an actin-linked regulatory protein in smooth muscle, caused a remarkable change in the fluorescence intensity of pyrene-labeled actin in the filamentous form. Calponin, an equimolar ratio to actin, decreased the fluorescence intensity of pyrene-labeled F-actin by some 60% to the level near monomeric actin. This change was partially reversed by Ca2+, when calmodulin was present. Thus it appears that calponin causes conformational changes in actin molecules in an actin filament so as to inhibit their interactions with myosin.
Noda
S
S
Department of Biology, Faculty of Science, Chiba University, Japan.
Ito
M
M
Watanabe
S
S
Takahashi
K
K
Maruyama
K
K
D000199:Actins / Q000187:drug effects*; D000818:Animals; D002135:Calcium-Binding Proteins / Q000494:pharmacology*; D002645:Chickens; D004305:Dose-Response Relationship, Drug; D008840:Microfilament Proteins; D009124:Muscle Proteins / Q000494:pharmacology*; D011487:Protein Conformation / Q000187:drug effects; D000096985:Calponins
D000199:Actins; D002135:Calcium-Binding Proteins; D008840:Microfilament Proteins; D009124:Muscle Proteins; D000096985:Calponins