Key result
Calponin-like protein from mussel bivalve muscle acts as a competitive inhibitor of actomyosin ATPase by increasing KATPase and decreasing Vmax.
Calponin-like protein from mussel smooth muscle acts as a competitive inhibitor of actomyosin ATPase.
Hypothesis-generating for invertebrate muscle regulation; leaves open any relevance to human cardiac contractility.
The goal of this work was to elucidate the mechanism of inhibition of the actin-activated ATPase of myosin subfragment-1 (S1) by the calponin-like protein from mussel bivalve muscle. The calponin-like protein (Cap) is a 40-kDa actin-binding protein from the bivalve muscle of the mussel Crenomytilus grayanus. Kinetic parameters Vmax and KATPase of actomyosin ATPase in the absence and the presence of Cap were determined to investigate the mechanism of inhibition. It was found that Cap mainly causes increase in KATPase value and to a lesser extent the decrease in Vmax, which indicates that it is most likely a competitive inhibitor of actomyosin ATPase. Analysis of Vmax and KATPase parameters in the presence of tropomyosin revealed that the latter is a noncompetitive inhibitor of the actomyosin ATPase.
No takes yet. Share an insight, caveat, or question.
Sirenko et al. (2016) studied this question. Calponin-like protein (Cap) vs. Absence of Cap was evaluated on Kinetic parameters Vmax and KATPase of actomyosin ATPase. Calponin-like protein from mussel bivalve muscle acts as a competitive inhibitor of actomyosin ATPase by increasing KATPase and decreasing Vmax.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: