[Interaction of isoforms of subfragment-1 of myosin, containing fluorescently labelled alkaline light chains, with muscle fiber actin].
Using polarization microfluorimetry, the interaction of myosin subfragment 1 (S1) isoforms containing alkali light chains A1 and A2 respectively (S1(A1) and S1(A2] with F-actin of single glycerinated rabbit skeletal muscle fibers was studied. The alkali light chains of S1 were substituted by reassociation for A1 or A2 chains modified by a fluorescent label (1.5-IAEDANS) at the single SH-group located in the C-terminus. It was found that in S1(A1) bound to muscle fiber F-actin the mobility of the fluorescent label is lower than in S1(A2). At the same time the S1(A1) and S1(A2) interaction with F-actin induces similar changes in polarized fluorescence of rhodamine linked to falloidine which, in turn, is specifically bound to F-actin. It is concluded that the both S1 isoforms bind to F-actin and produce similar effects on the conformational state of actin filaments in muscle fibers. Local differences between S1(A1) and S1(A2) seem to be due to the interaction of the N-terminus of A1 within S1(A1) with the C-terminal region of actin.
Levitskiĭ
D I
DI
Golitsyna
N L
NL
Nikolaeva
O P
OP
Borovikov
Iu S
IuS
D000199:Actins / Q000378:metabolism*; D000818:Animals; D005454:Fluorescence Polarization; D005456:Fluorescent Dyes; D009210:Myofibrils / Q000378:metabolism*; D015879:Myosin Subfragments / Q000378:metabolism*; D009282:Naphthalenesulfonates / Q000737:chemistry; D011817:Rabbits
D000199:Actins; D005456:Fluorescent Dyes; D015879:Myosin Subfragments; D009282:Naphthalenesulfonates; C006421:1,5-I-AEDANS
Vzaimodeĭstvie izoform subfragmenta-1 miozina, soderzhashchikh fluorestsentno mechennye shchelochnye legkie tsepi, s aktinom myshechnykh volokon.