کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2076693 1079460 2008 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
A possible mechanism for determining the directionality of myosin molecular motors
موضوعات مرتبط
مهندسی و علوم پایه ریاضیات مدل‌سازی و شبیه سازی
پیش نمایش صفحه اول مقاله
A possible mechanism for determining the directionality of myosin molecular motors
چکیده انگلیسی

There is a large superfamily of myosins, which play various fundamental roles in cellular motility. In this superfamily, most of myosins, including myosins II and V, move to the barbed end of an actin filament, whereas myosin VI was found to move in the opposite direction to the pointed end. Although myosin VI has structural differences compared with the other myosins, the mechanism for the reversal of the directionality has not been satisfactorily explained by conventional theories for myosin motility, including the widely accepted lever-arm hypothesis. In this paper, a simple mechanism for determining the directionality is proposed. The mechanism assumes that the driving force for the power stroke is caused by elastic energy stored within a myosin molecule at the joint between the head and the neck. The elastic energy originates from the attractive force between myosin and actin, and accumulates during the docking process. The energy of ATP is used to reduce the attractive force between myosin and actin and to facilitate the dissociation of these molecules. Therefore, it is not directly engaged in the power stroke. With this mechanism, the directionality of the myosin motility is simply determined by the direction of the neck with respect to the head in the dissociated configuration. This structural difference is actually observed in myosin VI. The same mechanism also explains the behavior of a backward moving engineered myosin. Computer simulations demonstrated the feasibility of this working mechanism.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biosystems - Volume 93, Issue 3, September 2008, Pages 172–180
نویسندگان
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