The effect of tropomyosin and heavy meromyosin on the flexibility of formin-nucleated actin filaments
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چکیده
Doctoral School: I n t e r d i s c i p l i n a r y M e d i c a l S c i e n c e s D o c t o r a l S c h o o l D 9 3 Head of the Doctoral School: P r o f . D r . B a l á z s S ü m e g i P r o g r a m : B 1 3 0 ; I n v e s t i g a t i n g f u n c t i o n a l p r o t e i n d y n a m i c s u s i n g b i o p h y s i c a l m e t h o d s H e a d o f t h e P r o g r a m : P r o f . D r . M i k l ó s N y i t r a i
منابع مشابه
Myosin and Tropomyosin Stabilize the Conformation of Formin-nucleated Actin Filaments*
The conformational elasticity of the actin cytoskeleton is essential for its versatile biological functions. Increasing evidence supports that the interplay between the structural and functional properties of actin filaments is finely regulated by actin-binding proteins; however, the underlying mechanisms and biological consequences are not completely understood. Previous studies showed that th...
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The mechanism for the potentiation of the actin-activated ATPase of smooth muscle myosin by tropomyosin is investigated using smooth muscle actin, tropomyosin, and heavy meromyosin. In the presence of tropomyosin, an increase in Vmax occurs with no effect on KATPase and Kbinding at 20 mM ionic strength. Utilizing N-ethylmaleimide-treated subfragment-1, which forms rigor complexes with actin in ...
متن کاملBinding of tropomyosin to copolymers of Acanthamoeba actin and muscle actin.
The binding of tropomyosin to F-actin is strongly dependent on M&+ concentration. With muscle actin, in the presence of 2 mu ATP, binding begins at 4 mM M&+ and is complete at about 4.75 mu Mg+ while, with Acanthamoeba actin, binding is initiated at 6 mu M&+ and reaches saturation at 8.5 InM Mg+. Copolymers of muscle and Acanthamoeba actin, however, behave as unique species of actin, each with ...
متن کاملBidirectional movement of actin filaments along tracks of heavy meromyosin and native thick filaments.
Flexibility of the myosin molecule was studied by an in vitro motility assay in terms of the direction of actin movement. Actin filaments can move in both directions on tracks of heavy meromyosin made on a nitrocellulose surface, and, furthermore, along the native thick filaments passing over their central bare zone. These observations indicate that the myosin molecule has a considerable flexib...
متن کاملInteraction between Acanthamoeba actin and rabbit skeletal muscle tropomyosin.
The binding of 125I-labeled muscle tropomyosin to Acanthamoeba and muscle actin was studied by ultracentrifugation and by the effect of tropomyosin on the actin-activated muscle heavy meromyosin ATPase activity. Binding of muscle tropomyosin to Acanthamoeba actin was much weaker than its binding to muscle actin. For example, at 5 mM MgCl2, 2 mM ATP, and 5 micronM actin, tropomyosin bound strong...
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