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Buonfiglio V, Pertici I, Marcello M, Morotti I, Caremani M, Reconditi M, Linari M, Fanelli D, Lombardi V, Bianco P. Force and kinetics of fast and slow muscle myosin determined with a synthetic sarcomere-like nanomachine. Commun Biol 2024; 7:361. [PMID: 38521889 PMCID: PMC10960843 DOI: 10.1038/s42003-024-06033-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 03/11/2024] [Indexed: 03/25/2024] Open
Abstract
Myosin II is the muscle molecular motor that works in two bipolar arrays in each thick filament of the striated (skeletal and cardiac) muscle, converting the chemical energy into steady force and shortening by cyclic ATP-driven interactions with the nearby actin filaments. Different isoforms of the myosin motor in the skeletal muscles account for the different functional requirements of the slow muscles (primarily responsible for the posture) and fast muscles (responsible for voluntary movements). To clarify the molecular basis of the differences, here the isoform-dependent mechanokinetic parameters underpinning the force of slow and fast muscles are defined with a unidimensional synthetic nanomachine powered by pure myosin isoforms from either slow or fast rabbit skeletal muscle. Data fitting with a stochastic model provides a self-consistent estimate of all the mechanokinetic properties of the motor ensemble including the motor force, the fraction of actin-attached motors and the rate of transition through the attachment-detachment cycle. The achievements in this paper set the stage for any future study on the emergent mechanokinetic properties of an ensemble of myosin molecules either engineered or purified from mutant animal models or human biopsies.
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Affiliation(s)
| | - Irene Pertici
- PhysioLab, University of Florence, Sesto Fiorentino, FI, Italy
| | - Matteo Marcello
- PhysioLab, University of Florence, Sesto Fiorentino, FI, Italy
| | - Ilaria Morotti
- PhysioLab, University of Florence, Sesto Fiorentino, FI, Italy
| | - Marco Caremani
- PhysioLab, University of Florence, Sesto Fiorentino, FI, Italy
| | | | - Marco Linari
- PhysioLab, University of Florence, Sesto Fiorentino, FI, Italy
| | - Duccio Fanelli
- Department of Physics and Astronomy, University of Florence, Sesto Fiorentino, FI, Italy.
| | | | - Pasquale Bianco
- PhysioLab, University of Florence, Sesto Fiorentino, FI, Italy
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Deng Z, Zhang Y, Yan S. Mechanism of elastic energy storage of honey bee abdominal muscles under stress relaxation. JOURNAL OF INSECT SCIENCE (ONLINE) 2023; 23:7176136. [PMID: 37220090 DOI: 10.1093/jisesa/iead026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 03/30/2023] [Accepted: 04/08/2023] [Indexed: 05/25/2023]
Abstract
Energy storage of passive muscles plays an important part in frequent activities of honey bee abdomens due to the muscle distribution and open circulatory system. However, the elastic energy and mechanical properties of structure in passive muscles remain unclear. In this article, stress relaxation tests on passive muscles from the terga of the honey bee abdomens were performed under different concentrations of blebbistatin and motion parameters. In stress relaxation, the load drop with the rapid and slow stages depending on stretching velocity and stretching length reflects the features of myosin-titin series structure and cross-bridge-actin cyclic connections in muscles. Then a model with 2 parallel modules based on the 2 feature structures in muscles was thus developed. The model described the stress relaxation and stretching of passive muscles from honey bee abdomen well for a good fitting in stress relaxation and verification in loading process. In addition, the stiffness change of cross-bridge under different concentrations of blebbistatin is obtained from the model. We derived the elastic deformation of cross-bridge and the partial derivatives of energy expressions on motion parameters from this model, which accorded the experimental results. This model reveals the mechanism of passive muscles from honey bee abdomens suggesting that the temporary energy storage of cross-bridge in terga muscles under abdomen bending provides potential energy for springback during the periodic abdomen bending of honey bee or other arthropod insects. The finding also provides an experimental and theoretical basis for the novel microstructure and material design of bionic muscle.
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Affiliation(s)
- Zhizhong Deng
- Division of Intelligent and Biomechanical Systems, State Key Laboratory of Tribology in Advanced Equipment, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, PR China
| | - Yuling Zhang
- Division of Intelligent and Biomechanical Systems, State Key Laboratory of Tribology in Advanced Equipment, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, PR China
| | - Shaoze Yan
- Division of Intelligent and Biomechanical Systems, State Key Laboratory of Tribology in Advanced Equipment, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, PR China
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Månsson A, Rassier DE. Insights into Muscle Contraction Derived from the Effects of Small-Molecular Actomyosin-Modulating Compounds. Int J Mol Sci 2022; 23:ijms232012084. [PMID: 36292937 PMCID: PMC9603234 DOI: 10.3390/ijms232012084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Revised: 09/25/2022] [Accepted: 10/03/2022] [Indexed: 01/10/2023] Open
Abstract
Bottom-up mechanokinetic models predict ensemble function of actin and myosin based on parameter values derived from studies using isolated proteins. To be generally useful, e.g., to analyze disease effects, such models must also be able to predict ensemble function when actomyosin interaction kinetics are modified differently from normal. Here, we test this capability for a model recently shown to predict several physiological phenomena along with the effects of the small molecular compound blebbistatin. We demonstrate that this model also qualitatively predicts effects of other well-characterized drugs as well as varied concentrations of MgATP. However, the effects of one compound, amrinone, are not well accounted for quantitatively. We therefore systematically varied key model parameters to address this issue, leading to the increased amplitude of the second sub-stroke of the power stroke from 1 nm to 2.2 nm, an unchanged first sub-stroke (5.3−5.5 nm), and an effective cross-bridge attachment rate that more than doubled. In addition to better accounting for the effects of amrinone, the modified model also accounts well for normal physiological ensemble function. Moreover, a Monte Carlo simulation-based version of the model was used to evaluate force−velocity data from small myosin ensembles. We discuss our findings in relation to key aspects of actin−myosin operation mechanisms causing a non-hyperbolic shape of the force−velocity relationship at high loads. We also discuss remaining limitations of the model, including uncertainty of whether the cross-bridge elasticity is linear or not, the capability to account for contractile properties of very small actomyosin ensembles (<20 myosin heads), and the mechanism for requirements of a higher cross-bridge attachment rate during shortening compared to during isometric contraction.
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Affiliation(s)
- Alf Månsson
- Department of Chemistry and Biomedical Sciences, Linnaeus University, 391 82 Kalmar, Sweden
- Correspondence: ; Tel.: +46-708-866243
| | - Dilson E. Rassier
- Department of Kinesiology and Physical Education, McGill University, Montreal, QC H2W 1S4, Canada
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Marcucci L, Fukunaga H, Yanagida T, Iwaki M. The Synergic Role of Actomyosin Architecture and Biased Detachment in Muscle Energetics: Insights in Cross Bridge Mechanism Beyond the Lever-Arm Swing. Int J Mol Sci 2021; 22:ijms22137037. [PMID: 34210098 PMCID: PMC8269045 DOI: 10.3390/ijms22137037] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 06/24/2021] [Accepted: 06/25/2021] [Indexed: 02/04/2023] Open
Abstract
Muscle energetics reflects the ability of myosin motors to convert chemical energy into mechanical energy. How this process takes place remains one of the most elusive questions in the field. Here, we combined experimental measurements of in vitro sliding velocity based on DNA-origami built filaments carrying myosins with different lever arm length and Monte Carlo simulations based on a model which accounts for three basic components: (i) the geometrical hindrance, (ii) the mechano-sensing mechanism, and (iii) the biased kinetics for stretched or compressed motors. The model simulations showed that the geometrical hindrance due to acto-myosin spatial mismatching and the preferential detachment of compressed motors are synergic in generating the rapid increase in the ATP-ase rate from isometric to moderate velocities of contraction, thus acting as an energy-conservation strategy in muscle contraction. The velocity measurements on a DNA-origami filament that preserves the motors’ distribution showed that geometrical hindrance and biased detachment generate a non-zero sliding velocity even without rotation of the myosin lever-arm, which is widely recognized as the basic event in muscle contraction. Because biased detachment is a mechanism for the rectification of thermal fluctuations, in the Brownian-ratchet framework, we predict that it requires a non-negligible amount of energy to preserve the second law of thermodynamics. Taken together, our theoretical and experimental results elucidate less considered components in the chemo-mechanical energy transduction in muscle.
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Affiliation(s)
- Lorenzo Marcucci
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
- Center for Biosystems Dynamics Research, RIKEN, Suita 5650874, Japan; (T.Y.); (M.I.)
- Correspondence:
| | - Hiroki Fukunaga
- Graduate School of Frontier Biosciences, Osaka University, Suita 5650871, Japan;
| | - Toshio Yanagida
- Center for Biosystems Dynamics Research, RIKEN, Suita 5650874, Japan; (T.Y.); (M.I.)
- Graduate School of Frontier Biosciences, Osaka University, Suita 5650871, Japan;
- Center for Information and Neural Networks, NICT, Suita 5650871, Japan
| | - Mitsuhiro Iwaki
- Center for Biosystems Dynamics Research, RIKEN, Suita 5650874, Japan; (T.Y.); (M.I.)
- Graduate School of Frontier Biosciences, Osaka University, Suita 5650871, Japan;
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Pertici I, Bianchi G, Bongini L, Cojoc D, Taft MH, Manstein DJ, Lombardi V, Bianco P. Muscle myosin performance measured with a synthetic nanomachine reveals a class-specific Ca 2+ -sensitivity of the frog myosin II isoform. J Physiol 2021; 599:1815-1831. [PMID: 33507554 DOI: 10.1113/jp280976] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 01/25/2021] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS A nanomachine made of an ensemble of seven heavy-meromyosin (HMM) fragments of muscle myosin interacting with an actin filament is able to mimic the half-sarcomere generating steady force and constant-velocity shortening. To preserve Ca2+ as a free parameter, the Ca2+ -insensitive gelsolin fragment TL40 is used to attach the correctly oriented actin filament to the laser-trapped bead acting as a force transducer. The new method reveals that the performance of the nanomachine powered by myosin from frog hind-limb muscles depends on [Ca2+ ], an effect mediated by a Ca2+ -binding site in the regulatory light chain of HMM. The Ca2+ -sensitivity is class-specific because the performance of the nanomachine powered by mammalian skeletal muscle myosin is Ca2+ independent. A model simulation is able to interface the nanomachine performance with that of the muscle of origin and provides a molecular explanation of the functional diversity of muscles with different orthologue isoforms of myosin. ABSTRACT An ensemble of seven heavy-meromyosin (HMM) fragments of myosin-II purified from the hindlimb muscles of the frog (Rana esculenta) is used to drive a synthetic nanomachine that pulls an actin filament in the absence of confounding effects of other sarcomeric proteins. In the present version of the nanomachine the +end of the actin filament is attached to the laser trapped bead via the Ca2+ -insensitive gelsolin fragment TL40, making [Ca2+ ] a free parameter. Frog myosin performance in 2 mm ATP is affected by Ca2+ : in 0.1 mm Ca2+ , the isometric steady force (F0 , 15.25 pN) is increased by 50% (P = 0.004) with respect to that in Ca2+ -free solution, the maximum shortening velocity (V0 , 4.6 μm s-1 ) is reduced by 27% (P = 0.46) and the maximum power (Pmax , 7.6 aW) is increased by 21% (P = 0.17). V0 reduction is not significant for the paucity of data at low force, although it is solidified by a similar decrease (33%, P < 0.0001) in the velocity of actin sliding as indicated by an in vitro motility assay (Vf ). The rate of ATP-hydrolysis in solution (φ) exhibits a similar calcium dependence. Ca2+ titration curves for Vf and φ give Kd values of ∼30 μm. All the above mechanical and kinetic parameters are independent of Ca2+ when HMM from rabbit psoas myosin is used, indicating that the Ca2+ -sensitivity is a class-specific property of muscle myosin. A unique multiscale model allows interfacing of the nanomachine performance to that of the muscle of origin and identifies the kinetic steps responsible for the Ca2+ -sensitivity of frog myosin.
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Affiliation(s)
- Irene Pertici
- PhysioLab, University of Florence, Sesto Fiorentino, FI, Italy
| | - Giulio Bianchi
- PhysioLab, University of Florence, Sesto Fiorentino, FI, Italy
| | - Lorenzo Bongini
- PhysioLab, University of Florence, Sesto Fiorentino, FI, Italy
| | | | - Manuel H Taft
- Institute for Biophysical Chemistry, Fritz-Hartmann-Centre for Medical Research, Medizinische Hochschule Hannover, Hannover, Germany
| | - Dietmar J Manstein
- Institute for Biophysical Chemistry, Fritz-Hartmann-Centre for Medical Research, Medizinische Hochschule Hannover, Hannover, Germany
| | | | - Pasquale Bianco
- PhysioLab, University of Florence, Sesto Fiorentino, FI, Italy
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Hypothesis: Single Actomyosin Properties Account for Ensemble Behavior in Active Muscle Shortening and Isometric Contraction. Int J Mol Sci 2020; 21:ijms21218399. [PMID: 33182367 PMCID: PMC7664901 DOI: 10.3390/ijms21218399] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Revised: 11/02/2020] [Accepted: 11/04/2020] [Indexed: 11/17/2022] Open
Abstract
Muscle contraction results from cyclic interactions between myosin II motors and actin with two sets of proteins organized in overlapping thick and thin filaments, respectively, in a nearly crystalline lattice in a muscle sarcomere. However, a sarcomere contains a huge number of other proteins, some with important roles in muscle contraction. In particular, these include thin filament proteins, troponin and tropomyosin; thick filament proteins, myosin binding protein C; and the elastic protein, titin, that connects the thin and thick filaments. Furthermore, the order and 3D organization of the myofilament lattice may be important per se for contractile function. It is possible to model muscle contraction based on actin and myosin alone with properties derived in studies using single molecules and biochemical solution kinetics. It is also possible to reproduce several features of muscle contraction in experiments using only isolated actin and myosin, arguing against the importance of order and accessory proteins. Therefore, in this paper, it is hypothesized that “single molecule actomyosin properties account for the contractile properties of a half sarcomere during shortening and isometric contraction at almost saturating Ca concentrations”. In this paper, existing evidence for and against this hypothesis is reviewed and new modeling results to support the arguments are presented. Finally, further experimental tests are proposed, which if they corroborate, at least approximately, the hypothesis, should significantly benefit future effective analysis of a range of experimental studies, as well as drug discovery efforts.
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Pertici I, Bianchi G, Bongini L, Lombardi V, Bianco P. A Myosin II-Based Nanomachine Devised for the Study of Ca 2+-Dependent Mechanisms of Muscle Regulation. Int J Mol Sci 2020; 21:E7372. [PMID: 33036217 PMCID: PMC7583892 DOI: 10.3390/ijms21197372] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 10/01/2020] [Accepted: 10/02/2020] [Indexed: 02/03/2023] Open
Abstract
The emergent properties of the array arrangement of the molecular motor myosin II in the sarcomere of the striated muscle, the generation of steady force and shortening, can be studied in vitro with a synthetic nanomachine made of an ensemble of eight heavy-meromyosin (HMM) fragments of myosin from rabbit psoas muscle, carried on a piezoelectric nanopositioner and brought to interact with a properly oriented actin filament attached via gelsolin (a Ca2+-regulated actin binding protein) to a bead trapped by dual laser optical tweezers. However, the application of the original version of the nanomachine to investigate the Ca2+-dependent regulation mechanisms of the other sarcomeric (regulatory or cytoskeleton) proteins, adding them one at a time, was prevented by the impossibility to preserve [Ca2+] as a free parameter. Here, the nanomachine is implemented by assembling the bead-attached actin filament with the Ca2+-insensitive gelsolin fragment TL40. The performance of the nanomachine is determined both in the absence and in the presence of Ca2+ (0.1 mM, the concentration required for actin attachment to the bead with gelsolin). The nanomachine exhibits a maximum power output of 5.4 aW, independently of [Ca2+], opening the possibility for future studies of the Ca2+-dependent function/dysfunction of regulatory and cytoskeletal proteins.
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Affiliation(s)
| | | | | | - Vincenzo Lombardi
- PhysioLab, University of Florence, 50019 Sesto Fiorentino (FI), Italy; (I.P.); (G.B.); (L.B.); (P.B.)
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