Oxidation alters myosin-actin interaction and force generation in skeletal muscle filaments

Abstract

The interaction between actin and myosin is the basis of contraction and force production in muscle fibers. Studies have shown that actin and myosin oxidation cause myofibrillar weakness in healthy and diseased muscles. The degree to which oxidation of each of these proteins contributes to an attenuated force in myofibrils is unclear. In this study, we show that exposure of actin and myosin to the chemical 5-amino-3-(4-morpholinyl)-1,2,3-oxadiazolium chloride (SIN-1), a NO and O2−• donor, affected actin-myosin interactions, as shown by a decreased myosin-propelled actin velocity in the in vitromotility assay. We also observed that oxidation of actin and myosin resulted in a decrease in force generated by myosin and actin filaments, as determined by a system of micro-fabricated cantilevers. While myosin is more sensitive to oxidative modifications than actin, as indicated by a steeper decrease in velocity and force by the filaments, modifications on actin are sufficient to affect force and velocity and also contribute to a decrease in contractile activity in muscles.

Signatures of cysteine oxidation on muscle structural and contractile proteins are associated with physical performance and muscle function in older adults: Study of Muscle, Mobility and Aging (SOMMA)

“…These sites have been identified as redox‐sensitive Cys residues in prior work comparing adult and aged mouse skeletal muscle (McDonagh et al., 2014 ). Oxidation of actin can disrupt interactions with myosin, resulting in attenuated contraction and force production (Elkrief et al., 2022 ).…”

Oxidation-induced structural changes in actin and myosin evaluated by computational simulation, machine learning modeling and high-speed AFM

“…We conducted HS-AFM experiments on both untreated and SIN-1-treated skeletal F-actin. The SIN treatment was performed according to our previous studies 12 and described in the Methods. T imaging of the non-oxidized F-actin and the oxidized by SIN-1 F-actin attached to the mica-suppor lipid bilayer surface (mica-SLB) was performed by the same cantilever to avoid any difference caus by tip cantilever collision during HS-AFM scanning (Fig.…”

“…The exact mechanism of the impaired contractility upon oxidation is still not clear, since the susceptibility of proteins to oxidation varies depending on the specific amino acids involved in the process 10 . Thus, a broad range of manifestations due to protein oxidation has been observed in vitro: reducing motility of actin filaments in the in-vitro motility assays 11, 12 , inhibition of the rate of polymerization of actin 2 and the myosin ATPase activity 13 , reducing force generation in the muscle fibers, myofibrils and myosin filaments 12,14, 15 . It was suggested that oxidation may lead to a reduction in the number of myosin crossbridges and thus a decrease in force generation 15 or increase in the rate of myosin head detachment from actin, further reducing muscle force.…”

“…It was suggested that oxidation may lead to a reduction in the number of myosin crossbridges and thus a decrease in force generation 15 or increase in the rate of myosin head detachment from actin, further reducing muscle force. Exposure of actin and myosin to oxidative agents affects actin-myosin interactions, leading to a decreased myosin-propelled actin velocity and a reduction in force generated by myosin and actin filaments 12 . Moreover, oxidative modifications on actin alone were sufficient to affect myosin force and velocity on actin filaments 2,12, 13 .…”

Signatures of Cysteine Oxidation on Muscle Structural and Contractile Proteins Are Associated with Physical Performance and Muscle Function in Older Adults: Study of Muscle, Mobility and Aging (SOMMA)

“…These sites have been identified as redox-sensitive Cys residues in prior work comparing adult and aged mouse skeletal muscle (McDonagh et al, 2014). Oxidation of actin can disrupt interactions with myosin, resulting in attenuated contraction and force production (Elkrief, Cheng, Matusovsky, & Rassier, 2022).…”