title: [Study of the modification of histidine residues, SH- and epsilon-NH2-groups of rat sarcoma-45 myosin by specific reagents].
abstract: Modification of histidine residues, SH- and epsilon-NH2-groups of myosin from rat sarcoma-45 by specific reagents was studied. It was shown that diethylpyrocarbonate modifies histidine residues essential for the ATPase activity. A kinetic analysis of myosin epsilon-NH2-groups modification by 2,4,6-trinitrobenzene sulfonate revealed that myosin trinitrophenylation and its inactivation by Ca2(+)-ATPase occurs in two steps: a fast and a slow (Km = 2400 and 1.7 s-1 M-1, respectively). Two essential epsilon-NH2-groups of tumour myosin active sites react in the fast reaction. The relatively low concentrations of p-chloromercuribenzoic acid activate rat sarcoma-45 myosin Ca2(+)-ATPase and Mg2(+)-ATPase, whereas higher ones inhibit the enzyme. The data obtained suggest that two SH-groups, SH1 and SH2 are essential for the tumour myosin ATPase function.
authors: V V
authors: VV
authors: Senchuk
authors: A T
authors: AT
authors: Pikulev
authors: I N
authors: IN
authors: Dashkevich
mesh_terms: D000588:Amines / Q000737:chemistry; D000818:Animals; D017301:Ca(2+) Mg(2+)-ATPase / Q000187:drug effects; D000252:Calcium-Transporting ATPases / Q000187:drug effects; D002729:Chloromercuribenzoates / Q000494:pharmacology*; D004047:Diethyl Pyrocarbonate / Q000494:pharmacology*; D006639:Histidine / Q000187:drug effects; D009218:Myosins / Q000187:drug effects*; D009363:Neoplasm Proteins / Q000187:drug effects*; D051381:Rats; D012513:Sarcoma, Experimental / Q000737:chemistry*; D013439:Sulfhydryl Reagents; D014302:Trinitrobenzenesulfonic Acid / Q000494:pharmacology*; D020245:p-Chloromercuribenzoic Acid
chemical_list: D000588:Amines; D002729:Chloromercuribenzoates; D009363:Neoplasm Proteins; D013439:Sulfhydryl Reagents; D006639:Histidine; D020245:p-Chloromercuribenzoic Acid; D014302:Trinitrobenzenesulfonic Acid; D017301:Ca(2+) Mg(2+)-ATPase; D009218:Myosins; D000252:Calcium-Transporting ATPases; D004047:Diethyl Pyrocarbonate
vernacular_title: Issledovanie modifikatsii spetsificheskimi reagentami ostatkov gistidina, SH- i epsilon-NH2-grupp miozina iz zlokachestvennoĭ opukholi krys sarkoma-45.