期刊
CELL REPORTS
卷 14, 期 6, 页码 1339-1347出版社
CELL PRESS
DOI: 10.1016/j.celrep.2016.01.025
关键词
-
类别
资金
- NIH [GM116122, HL061228]
- NSF [DBI-1252857]
- Deutsche Forschungsgemeinschaft [SFB1002]
- Div Of Biological Infrastructure
- Direct For Biological Sciences [1252857] Funding Source: National Science Foundation
Current theories of muscle contraction propose that the power stroke of a myosin motor is the sole source of mechanical energy driving the sliding filaments of a contracting muscle. These models exclude titin, the largest protein in the human body, which determines the passive elasticity of muscles. Here, we show that stepwise unfolding/folding of titin immunoglobulin (Ig) domains occurs in the elastic I band region of intact myofibrils at physiological sarcomere lengths and forces of 6-8 pN. We use single-molecule techniques to demonstrate that unfolded titin Ig domains undergo a spontaneous stepwise folding contraction at forces below 10 pN, delivering up to 105 zJ of additional contractile energy, which is larger than the mechanical energy delivered by the power stroke of a myosin motor. Thus, it appears inescapable that folding of titin Ig domains is an important, but as yet unrecognized, contributor to the force generated by a contracting muscle.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据