ArticleThe Journal of physiology2020
Contracting striated muscle has a dynamic I-band spring with an undamped stiffness 100 times larger than the passive stiffness.
Article in The Journal of physiology, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 11 papers.
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11 citing papers in PubMed, 23 citations in OpenAlex.
- Effects of chemical myosin II cross-bridge inhibitors on eccentric force production in skinned muscle fibres.Experimental physiology · 2026Article
- An integrated picture of the structural pathways controlling the heart performance.Proceedings of the National Academy of Sciences of the United States of America · 2024Article
- Re‑examining the mechanism of eccentric exercise‑induced skeletal muscle damage from the role of the third filament, titin (Review).Biomedical reports · 2024Review
- Titin activates myosin filaments in skeletal muscle by switching from an extensible spring to a mechanical rectifier.Proceedings of the National Academy of Sciences of the United States of America · 2023Article
- Effects of shortening velocity on the stiffness to force ratio during isometric force redevelopment suggest mechanisms of residual force depression.Scientific reports · 2023Article
- Power Amplification Increases With Contraction Velocity During Stretch-Shortening Cycles of Skinned Muscle Fibers.Frontiers in physiology · 2021Article
- Non-cross Bridge Viscoelastic Elements Contribute to Muscle Force and Work During Stretch-Shortening Cycles: Evidence From Whole Muscles and Permeabilized Fibers.Frontiers in physiology · 2021Article
- Article
- History-dependence of muscle slack length in humans: effects of contraction intensity, stretch amplitude, and time.Journal of applied physiology (Bethesda, Md. : 1985) · 2020Article
- A new spring for titin.The Journal of physiology · 2020Article
- Energy Cost of Force Production After a Stretch-Shortening Cycle in Skinned Muscle Fibers: Does Muscle Efficiency Increase?Frontiers in physiology · 2020Article
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6 authors at 2 institutions in 2 countries.
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Abstract
key pointsFast sarcomere-level mechanics in contracting intact fibres from frog skeletal muscle reveal an I-band spring with an undamped stiffness 100 times larger than the known static stiffness. This undamped stiffness remains constant in the range of sarcomere length 2.7-3.1 µm, showing the ability of the I-band spring to adapt its length to the width of the I-band. The stiffness and tunability of the I-band spring implicate titin as a force contributor that, during contraction, allows weaker half-sarcomeres to equilibrate with in-series stronger half-sarcomeres, preventing the development of sarcomere length inhomogeneity. This work opens new possibilities for the detailed in situ description of the structural-functional basis of muscle dysfunctions related to mutations or site-directed mutagenesis in titin that alter the I-band stiffness. ABSTRACT: Force and shortening in the muscle sarcomere are due to myosin motors from thick filaments pulling nearby actin filaments toward the sarcomere centre. Thousands of serially linked sarcomeres in muscle make the shortening (and the shortening speed) macroscopic, while the intrinsic instability of in-series force generators is likely prevented by the cytoskeletal protein titin that connects the thick filament with the sarcomere end, working as an I-band spring that accounts for the rise of passive force with sarcomere length (SL). However, current estimates of titin stiffness, deduced from the passive force-SL relation and single molecule mechanics, are much smaller than what is required to avoid the development of large inhomogeneities among sarcomeres. In this work, using 4 kHz stiffness measurements on a population of sarcomeres selected along an intact fibre isolated from frog skeletal muscle contracting at different SLs (temperature 4°C), we measure the undamped stiffness of an I-band spring that at SL > 2.7 µm attains a maximum constant value of ∼6 pN nm
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