期刊
JOURNAL OF EXPERIMENTAL BIOLOGY
卷 219, 期 9, 页码 1311-1316出版社
COMPANY OF BIOLOGISTS LTD
DOI: 10.1242/jeb.132027
关键词
Myofibrils; Eccentric contractions; Stiffness; Muscular dystrophy with myositis; Cross-bridges
类别
资金
- Alberta Innovates - Technology Futures
- Natural Sciences and Engineering Research Council of Canada
- Canadian Institutes of Health Research
- Canada Research Chairs Program
- Killam Trusts
- National Science Foundation [IOS-1025806, IIP-1237878]
- W.M. Keck Foundation
- Northern Arizona University Technology Research Initiative Fund
- Direct For Biological Sciences
- Division Of Integrative Organismal Systems [1456868] Funding Source: National Science Foundation
In the cross-bridge theory, contractile force is produced by cross-bridges that form between actin and myosin filaments. However, when a contracting muscle is stretched, its active force vastly exceeds the force that can be attributed to cross-bridges. This unexplained, enhanced force has been thought to originate in the giant protein titin, which becomes stiffer in actively compared with passively stretched sarcomeres by an unknown mechanism. We investigated this mechanism using a genetic mutation (mdm) with a small but crucial deletion in the titin protein. Myofibrils from normal and mdm mice were stretched from sarcomere lengths of 2.5 to 6.0 mu m. Actively stretched myofibrils from normal mice were stiffer and generated more force than passively stretched myofibrils at all sarcomere lengths. No increase in stiffness and just a small increase in force were observed in actively compared with passively stretched mdm myofibrils. These results are in agreement with the idea that titin force enhancement stiffens and stabilizes the sarcomere during contraction and that this mechanism is lost with the mdm mutation.
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