کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1956559 1057863 2006 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Extending a Spectrin Repeat Unit. II: Rupture Behavior
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Extending a Spectrin Repeat Unit. II: Rupture Behavior
چکیده انگلیسی

A spectrin repeat unit was subject to extension using cyclic expansion nonequilibrium molecular dynamics. Periodic boundary conditions were used to examine the effects of the contiguous α-helical linker on the force response. The measured force-extension curve shows a linear increase in the force response when the spectrin repeat unit is extended by ∼0.4 nm. After that point, the force response peaks and subsequently declines. The peak in the force response marks the point where the spectrin repeat unit undergoes a change in its material properties from a strongly elastic material to a mostly viscous one, on the timescales of the simulations. The force peak is also correlated with rupture of the α-helical linker, and is likely the event responsible for the peaks in the sawtooth-pattern force-extension curves measured by atomic force microscopy experiments. Rupture of the linker involves simultaneously breaking approximately four hydrogen bonds that maintain the α-helical linker. After this initial rupture, the linker undergoes simple helix-to-coil transitions as the spectrin repeat unit continues to be extended. The implications of linker rupture in the interpretation of unfolding and atomic force microscopy experiments are also discussed.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: - Volume 90, Issue 1, 1 January 2006, Pages 101–111
نویسندگان
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