Chymotryptic digestion of myosin yields a subfragment with distinct enzymatic properties, including higher ATPase activity in the presence of F-actin and the ability to accelerate actin polymerization.
This myosin subfragment's properties warrant further investigation in muscle models; leaves open implications for cardiac contractility regulation.
An enzymatically active subfragment was isolated from heavy meromyosin and also from myosin aggregate after the chymotryptic digestion at low temperature. The adenosine-triphosphatase (EC 3. 6. 1. 3) activity in the presence of C2+ was 1.0μ mole of P1 liberated per mg protein per min. The molecular weight of this subfragment was about 1.0×105. The two properties were indistinguishable from those of sub-fragments prepared by using other proteolytic enzymes. In the presence of F-actin, however, the adenosine-triphosphatase activity of this subfragment was considerably higher than that of other subfragments. Actin polymerization was accelerated by this subfragment as heavy meromyosin does, while it was not accelerated by the subfragment prepared by the tryptic digestion.
No takes yet. Share an insight, caveat, or question.
Onodera et al. (1971) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: