Non-binding property of cathepsin L to myosin

Disodium pyrophosphate at 10 mM concentration, was effective in dissociating myosin and actin from actomyosin in walleye pollock (Theragra chalcogramma) surimi and red bulleye (Priacanthus macracanthus) surimi. After Sepharose 2B gel filtration, cathepsin L contained in the actomyosin was obviously non-binding to myosin. Actomyosin from carp (Cyprinus carpio) muscle was not dissociated in pyrophosphate solution in the absence of MgCl₂ and it was successfully dissociated by 10 mM pyrophosphate in the presence of 2 mM MgCl₂. Cathepsin L in carp actomyosin was shown to be much more complicated than that in the above two surimis. After Sepharose 2B gel filtration, there were two activity peaks of cathepsin L in carp, one almost corresponding with actomyosin, the other obviously separated from actomyosin. Both of the peaks were non-binding to myosin.