کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1925190 1536348 2014 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Random myosin loss along thick-filaments increases myosin attachment time and the proportion of bound myosin heads to mitigate force decline in skeletal muscle
ترجمه فارسی عنوان
کاهش تصادفی میوزین در طول رشته های ضخیم، باعث افزایش زمان دلبستگی میوزین و نسبت سرخوشت های میوزین می شود تا کاهش نیرو در عضلات اسکلتی
کلمات کلیدی
مکانیک عضلانی ساختار سارکومر، رشته های ضخیم مدل سازی محاسباتی، سینتیک عبور پل
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
چکیده انگلیسی


• Myosin loss may diminish muscle fiber performance with aging, disuse, and disease.
• Computational models of myosin loss reduced cross-bridge number and fiber force.
• Random myosin loss resulted in a smaller fiber force decrements than uniform loss.
• Myosin attachment time and cross-bridge binding increased with random myosin.
• Results support prior findings in heart failure patients with random myosin loss.

Diminished skeletal muscle performance with aging, disuse, and disease may be partially attributed to the loss of myofilament proteins. Several laboratories have found a disproportionate loss of myosin protein content relative to other myofilament proteins, but due to methodological limitations, the structural manifestation of this protein loss is unknown. To investigate how variations in myosin content affect ensemble cross-bridge behavior and force production we simulated muscle contraction in the half-sarcomere as myosin was removed either (i) uniformly, from the Z-line end of thick-filaments, or (ii) randomly, along the length of thick-filaments. Uniform myosin removal decreased force production, showing a slightly steeper force-to-myosin content relationship than the 1:1 relationship that would be expected from the loss of cross-bridges. Random myosin removal also decreased force production, but this decrease was less than observed with uniform myosin loss, largely due to increased myosin attachment time (ton) and fractional cross-bridge binding with random myosin loss. These findings support our prior observations that prolonged ton may augment force production in single fibers with randomly reduced myosin content from chronic heart failure patients. These simulations also illustrate that the pattern of myosin loss along thick-filaments influences ensemble cross-bridge behavior and maintenance of force throughout the sarcomere.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Archives of Biochemistry and Biophysics - Volumes 552–553, 15 June–1 July 2014, Pages 117–127
نویسندگان
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