1
|
Ranatunga KW. Temperature Effects on Force and Actin⁻Myosin Interaction in Muscle: A Look Back on Some Experimental Findings. Int J Mol Sci 2018; 19:E1538. [PMID: 29786656 PMCID: PMC5983754 DOI: 10.3390/ijms19051538] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 05/14/2018] [Accepted: 05/16/2018] [Indexed: 01/23/2023] Open
Abstract
Observations made in temperature studies on mammalian muscle during force development, shortening, and lengthening, are re-examined. The isometric force in active muscle goes up substantially on warming from less than 10 °C to temperatures closer to physiological (>30 °C), and the sigmoidal temperature dependence of this force has a half-maximum at ~10 °C. During steady shortening, when force is decreased to a steady level, the sigmoidal curve is more pronounced and shifted to higher temperatures, whereas, in lengthening muscle, the curve is shifted to lower temperatures, and there is a less marked increase with temperature. Even with a small rapid temperature-jump (T-jump), force in active muscle rises in a definitive way. The rate of tension rise is slower with adenosine diphosphate (ADP) and faster with increased phosphate. Analysis showed that a T-jump enhances an early, pre-phosphate release step in the acto-myosin (crossbridge) ATPase cycle, thus inducing a force-rise. The sigmoidal dependence of steady force on temperature is due to this endothermic nature of crossbridge force generation. During shortening, the force-generating step and the ATPase cycle are accelerated, whereas during lengthening, they are inhibited. The endothermic force generation is seen in different muscle types (fast, slow, and cardiac). The underlying mechanism may involve a structural change in attached myosin heads and/or their attachments on heat absorption.
Collapse
Affiliation(s)
- K W Ranatunga
- School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol BS8 1TD, UK.
| |
Collapse
|
2
|
Sugi H, Chaen S, Akimoto T. Electron Microscopic Recording of the Power and Recovery Strokes of Individual Myosin Heads Coupled with ATP Hydrolysis: Facts and Implications. Int J Mol Sci 2018; 19:ijms19051368. [PMID: 29734671 PMCID: PMC5983685 DOI: 10.3390/ijms19051368] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 04/26/2018] [Accepted: 04/27/2018] [Indexed: 11/16/2022] Open
Abstract
The most straightforward way to get information on the performance of individual myosin heads producing muscle contraction may be to record their movement, coupled with ATP hydrolysis, electron-microscopically using the gas environmental chamber (EC). The EC enables us to visualize and record ATP-induced myosin head movement in hydrated skeletal muscle myosin filaments. When actin filaments are absent, myosin heads fluctuate around a definite neutral position, so that their time-averaged mean position remains unchanged. On application of ATP, myosin heads are found to move away from, but not towards, the bare region, indicating that myosin heads perform a recovery stroke (average amplitude, 6 nm). After exhaustion of ATP, myosin heads return to their neutral position. In the actin⁻myosin filament mixture, myosin heads form rigor actin myosin linkages, and on application of ATP, they perform a power stroke by stretching adjacent elastic structures because of a limited amount of applied ATP ≤ 10 µM. The average amplitude of the power stroke is 3.3 nm and 2.5 nm at the distal and the proximal regions of the myosin head catalytic domain (CAD), respectively. The power stroke amplitude increases appreciably at low ionic strength, which is known to enhance Ca2+-activated force in muscle. In both the power and recovery strokes, myosin heads return to their neutral position after exhaustion of ATP.
Collapse
Affiliation(s)
- Haruo Sugi
- Department of Physiology, School of Medicine, Teikyo University, Tokyo, Japan.
| | - Shigeru Chaen
- Department of Integrated Sciences in Physics and Biology, College of Humanities and Science, Nihon University, Tokyo, Japan.
| | - Tsuyoshi Akimoto
- Department of Physiology, School of Medicine, Teikyo University, Tokyo, Japan.
| |
Collapse
|
3
|
Ranatunga KW, Offer G. The force-generation process in active muscle is strain sensitive and endothermic: a temperature-perturbation study. ACTA ACUST UNITED AC 2017; 220:4733-4742. [PMID: 29084851 DOI: 10.1242/jeb.167197] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 10/26/2017] [Indexed: 11/20/2022]
Abstract
In experiments on active muscle, we examined the tension decline and its temperature sensitivity at the onset of ramp shortening and at a range of velocities. A segment (∼1.5 mm long) of a skinned muscle fibre isolated from rabbit psoas muscle was held isometrically (sarcomere length ∼2.5 µm) at 8-9°C, maximally Ca2+-activated and a ramp shortening applied. The tension decline with a ramp shortening showed an early decrease of slope (the P1 transition) followed by a slower decrease in slope (the P2 transition) to the steady (isotonic) force. The tension level at the initial P1 transition and the time to that transition decreased as the velocity was increased; the length change to this transition increased with shortening velocity to a steady value of ∼8 nm half-sarcomere-1 A small, rapid, temperature jump (T-jump) (3-4°C, <0.2 ms) applied coincident with the onset of ramp shortening showed force enhancement by T-jump and changed the tension decline markedly. Analyses showed that the rate of T-jump-induced force rise increased linearly with increase of shortening velocity. These results provide crucial evidence that the strain-sensitive cross-bridge force generation, or a step closely coupled to it, is endothermic.
Collapse
Affiliation(s)
- K W Ranatunga
- Muscle Contraction Group, School of Physiology, Pharmacology & Neurosciences, Medical Sciences Building, University of Bristol, Bristol BS8 1TD, UK
| | - Gerald Offer
- Muscle Contraction Group, School of Physiology, Pharmacology & Neurosciences, Medical Sciences Building, University of Bristol, Bristol BS8 1TD, UK
| |
Collapse
|
4
|
Tension Recovery following Ramp-Shaped Release in High-Ca and Low-Ca Rigor Muscle Fibers: Evidence for the Dynamic State of AMADP Myosin Heads in the Absence of ATP. PLoS One 2016; 11:e0162003. [PMID: 27583360 PMCID: PMC5008834 DOI: 10.1371/journal.pone.0162003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 08/16/2016] [Indexed: 11/19/2022] Open
Abstract
During muscle contraction, myosin heads (M) bound to actin (A) perform power stroke associated with reaction, AMADPPi → AM + ADP + Pi. In this scheme, A • M is believed to be a high-affinity complex after removal of ATP. Biochemical studies on extracted protein samples show that, in the AM complex, actin-binding sites are located at both sides of junctional peptide between 50K and 20K segments of myosin heavy chain. Recently, we found that a monoclonal antibody (IgG) to the junctional peptide had no effect on both in vitro actin-myosin sliding and skinned muscle fiber contraction, though it covers the actin-binding sites on myosin. It follows from this that, during muscle contraction, myosin heads do not pass through the static rigor AM configuration, determined biochemically and electron microscopically using extracted protein samples. To study the nature of AM and AMADP myosin heads, actually existing in muscle, we examined mechanical responses to ramp-shaped releases (0.5% of Lo, complete in 5ms) in single skinned rabbit psoas muscle fibers in high-Ca (pCa, 4) and low-Ca (pCa, >9) rigor states. The fibers exhibited initial elastic tension drop and subsequent small but definite tension recovery to a steady level. The tension recovery was present over many minutes in high-Ca rigor fibers, while it tended to decrease quickly in low-Ca rigor fibers. EDTA (10mM, with MgCl2 removed) had no appreciable effect on the tension recovery in high-Ca rigor fibers, while it completely eliminated the tension recovery in low-Ca rigor fibers. These results suggest that the AMADP myosin heads in rigor muscle have long lifetimes and dynamic properties, which show up as the tension recovery following applied release. Possible AM linkage structure in muscle is discussed in connection with the X-ray diffraction pattern from contracting muscle, which is intermediate between resting and rigor muscles.
Collapse
|
5
|
Sugi H, Chaen S, Kobayashi T, Abe T, Kimura K, Saeki Y, Ohnuki Y, Miyakawa T, Tanokura M, Sugiura S. Definite differences between in vitro actin-myosin sliding and muscle contraction as revealed using antibodies to myosin head. PLoS One 2014; 9:e93272. [PMID: 24918754 PMCID: PMC4053314 DOI: 10.1371/journal.pone.0093272] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Accepted: 03/04/2014] [Indexed: 11/18/2022] Open
Abstract
Muscle contraction results from attachment-detachment cycles between myosin heads extending from myosin filaments and actin filaments. It is generally believed that a myosin head first attaches to actin, undergoes conformational changes to produce force and motion in muscle, and then detaches from actin. Despite extensive studies, the molecular mechanism of myosin head conformational changes still remains to be a matter for debate and speculation. The myosin head consists of catalytic (CAD), converter (CVD) and lever arm (LD) domains. To give information about the role of these domains in the myosin head performance, we have examined the effect of three site-directed antibodies to the myosin head on in vitro ATP-dependent actin-myosin sliding and Ca2+-activated contraction of muscle fibers. Antibody 1, attaching to junctional peptide between 50K and 20K heavy chain segments in the CAD, exhibited appreciable effects neither on in vitro actin-myosin sliding nor muscle fiber contraction. Since antibody 1 covers actin-binding sites of the CAD, one interpretation of this result is that rigor actin-myosin linkage is absent or at most a transient intermediate in physiological actin-myosin cycling. Antibody 2, attaching to reactive lysine residue in the CVD, showed a marked inhibitory effect on in vitro actin-myosin sliding without changing actin-activated myosin head (S1) ATPase activity, while it showed no appreciable effect on muscle contraction. Antibody 3, attaching to two peptides of regulatory light chains in the LD, had no significant effect on in vitro actin-myosin sliding, while it reduced force development in muscle fibers without changing MgATPase activity. The above definite differences in the effect of antibodies 2 and 3 between in vitro actin-myosin sliding and muscle contraction can be explained by difference in experimental conditions; in the former, myosin heads are randomly oriented on a glass surface, while in the latter myosin heads are regularly arranged within filament-lattice structures.
Collapse
Affiliation(s)
- Haruo Sugi
- Department of Physiology, School of Medicine, Teikyo University, Tokyo, Japan
| | - Shigeru Chaen
- Department of Integrated Sciences in Physics and Biology, College of Humanities and Sciences, Nihon University, Tokyo, Japan
| | - Takakazu Kobayashi
- Department of Electronic Engineering, Shibaura Institute of Technology, Tokyo, Japan
| | - Takahiro Abe
- Department of Electronic Engineering, Shibaura Institute of Technology, Tokyo, Japan
| | - Kazushige Kimura
- Department of Electronic Engineering, Shibaura Institute of Technology, Tokyo, Japan
| | - Yasutake Saeki
- Department of Physiology, School of Dentistry, Tsurumi University, Yokohama, Japan
| | - Yoshiki Ohnuki
- Department of Physiology, School of Dentistry, Tsurumi University, Yokohama, Japan
| | - Takuya Miyakawa
- Department of Applied Biochemistry, Graduate School of Agriculture and Life Sciences, University of Tokyo, Tokyo, Japan
| | - Masaru Tanokura
- Department of Applied Biochemistry, Graduate School of Agriculture and Life Sciences, University of Tokyo, Tokyo, Japan
| | - Seiryo Sugiura
- Graduate School of Frontier Sciences, University of Tokyo, Tokyo, Japan
| |
Collapse
|
6
|
The effects of Ca2+ and MgADP on force development during and after muscle length changes. PLoS One 2013; 8:e68866. [PMID: 23874795 PMCID: PMC3712921 DOI: 10.1371/journal.pone.0068866] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Accepted: 06/07/2013] [Indexed: 11/19/2022] Open
Abstract
The goal of this study was to compare the effects of Ca2+ and MgADP activation on force development in skeletal muscles during and after imposed length changes. Single fibres dissected from the rabbit psoas were (i) activated in pCa2+4.5 and pCa2+6.0, or (ii) activated in pCa2+4.5 before and after administration of 10 mM MgADP. Fibres were activated in sarcomere lengths (SL) of 2.65 µm and 2.95 µm, and subsequently stretched or shortened (5%SL at 1.0 SL.s−1) to reach a final SL of 2.80 µm. The kinetics of force during stretch were not altered by pCa2+ or MgADP, but the fast change in the slope of force development (P1) observed during shortening and the corresponding SL extension required to reach the change (L1) were higher in pCa2+6.0 (P1 = 0.22±0.02 Po; L1 = 5.26±0.24 nm.HS.1) than in pCa2+4.5 (P1 = 0.15±0.01 Po; L1 = 4.48±0.25 nm.HS.1). L1 was also increased by MgADP activation during shortening. Force enhancement after stretch was lower in pCa2+4.5 (14.9±5.4%) than in pCa2+6.0 (38.8±7.5%), while force depression after shortening was similar in both Ca2+ concentrations. The stiffness accompanied the force behavior after length changes in all situations. MgADP did not affect the force behavior after length changes, and stiffness did not accompany the changes in force development after stretch. Altogether, these results suggest that the mechanisms of force generation during and after stretch are different from those obtained during and after shortening.
Collapse
|
7
|
Mechanical and kinetic properties of β-cardiac/slow skeletal muscle myosin. J Muscle Res Cell Motil 2012; 33:403-17. [DOI: 10.1007/s10974-012-9315-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Accepted: 07/06/2012] [Indexed: 11/26/2022]
|