Time-resolved x-ray diffraction studies on the intensity changes of the 5.9 and 5.1 nm actin layer lines from frog skeletal muscle during an isometric tetanus using synchrotron radiation

Wakabayashi, Katsuzo; Tanaka, Hidehiro; Amemiya, Yoshiyuki; Fujishima, Atsushi; Kobayashi, Takakazu; Hamanaka, Toshiaki; Sugi, Haruo; Mitsui, T.

doi:10.1016/s0006-3495(85)83989-8

Cited by 40 publications

(26 citation statements)

References 9 publications

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“…The change in the intensity ratio of the 1-0 and 1-1 equatorial reflections from frog skeletal muscle is generally taken to result from the radial movement of the cross-bridges towards the thin filaments, and is also known to lead the force development (Huxley, 1975;Matsubara & Yagi, 1978;Amemiya, Sugi & Hashizume, 1979). Recently, it has been shown that the increase in the intensity of the 5'9 and 17'9 nm actin layer lines precedes the change in the equatorial reflections in contracting frog skeletal muscle (Wakabayashi, Tanaka, Amemiya, Fujishima, Kobayashi, Hamanaka, Sugi & Mitsui, 1985;Kress, Huxley, Faruqi & Hendrix, 1986). These changes in the actin layer line intensities still take place in muscles stretched beyond myofilament overlap, indicating that they reflect structural changes when the thin filaments are activated by Ca2+.…”

Section: Discussionmentioning

confidence: 99%

Stiffness changes in frog skeletal muscle during contraction recorded using ultrasonic waves.

Hatta

Sugi

Tamura

1988

The Journal of Physiology

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SUMMARY1. A technique has been developed with which the stiffness changes in frog skeletal muscle can be continuously recorded by measuring the propagation velocity of ultrasonic waves (3-7 MHz) with negligibly small perturbations to the contractile system.2. The resting muscle stiffness was 2 256+00002 x 109 N/m2 (S.D.) at 1-2°C (n = 10) and 2-480+0-007 x 109 N/M2 at 19-20°C (n = 12) in the longitudinal direction, and 2-223 + 04008 x 109 N/m2 at 1-2°C (n = 8) and 2 437 + 0 007 x 109 N/M2 at 19-20°C (n = 9) in the transverse direction.3. The resting muscle stiffness measured with ultrasonic waves was virtually insensitive to the resting force development, i.e. the extension of the parallel elastic component.4. The longitudinal muscle stiffness increased during isometric contraction at a rate faster than the force development. The amount of increase of the longitudinal stiffness in an isometric tetanus at 2 2 ,um sarcomere length was 24 ±+01 x 107 N/M2 at 1-2°C (n = 10) and 6-5 + 1-3 x 107 N/m2 at 19-20°C (n = 12).5. On the other hand, the transverse muscle stiffness decreased during isometric contraction at a rate faster than the force development. The amount of decrease of the transverse stiffness in an isometric tetanus at 22 jtm sarcomere length was 5-6+01 x 107 N/M2 at 1-2°C (n = 8) and 64+0-3 x 107 N/M2 at 19-20°C (n = 9).6. The amount of both the longitudinal and the transverse stiffness changes during an isometric tetanus decreased linearly with increasing sarcomere length, indicating that the stiffness changes during contraction reflect the formation of cross-links between the myofilaments.7. Both the longitudinal and the transverse stiffness increased when resting muscle was put into rigor state. The rigor muscle stiffness was insensitive to small stretches, i.e. the strain of the rigor cross-links.8. These results are discussed in connection with the behaviour of cross-bridges during isometric contraction and in rigor.

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Section: Discussionmentioning

confidence: 99%

Stiffness changes in frog skeletal muscle during contraction recorded using ultrasonic waves.

Hatta

Sugi

Tamura

1988

The Journal of Physiology

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“…The failure earlier to detect intensity changes in this reflection had been the basis for ruling out large structural changes in actin filaments during contraction (26). Recently, however, it has become technically possible to detect rather large changes in the 59-A reflection, especially during the early rapid phase of tension development (27)(28)(29).…”

Section: Reexamination Of Other Observationsmentioning

confidence: 99%

Actin as the generator of tension during muscle contraction.

Schutt

Lindberg

1992

Proc. Natl. Acad. Sci. U.S.A.

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We propose that the key s tural feature in the conversion of chemical free energy into mechanical work by actomyosin is a myosin-induced change in the length of the actin filament. As reported earlier, there is evidence that helical actin filaments can untwist into ribbons having an increased intersubunit repeat. Regular patterns of actomyosin interactions arise when ribbons are aligned with myosin thick filaments, because the repeat distance of the myosin lattice (429 A) is an integral multiple of the subunit repeat in the ribbon (35.7 A). This commensurability property of the actomyosin lattice leads to a simple mechanism for controlling the sequence of events in chemical-mechanical transduction. A role for tropomyosin in transmitting the forces developed by actomyosin is proposed. In this paper, we describe how these transduction principles provide the basis for a theory of muscle contraction.The central problem of muscle contraction is to account for the mechanism offorce generation between the thick and thin filaments that constitute the sarcomere (1-6). In Huxley's analysis (3,5,6), the proportionality of isometric tension to the overlap of thick and thin filaments, as well as the other mechanical properties of muscle, are neatly explained with so-called independent force generators that are presumed to be distributed uniformly along the overlap zone. In most models, the individual force contributions of these generators are summed up by some relatively inextensible structural element to which each generator has a single point of attachment. In the case of the classical rotating cross-bridge model of force generation, thin filaments themselves serve the role of the inextensible structural elements. In this note, we propose an alternative model in which repetitive length changes in segments of actin filaments, induced by myosin heads, generate forces that are summed and transmitted to the Z disc by tropomyosin.The impetus for this model came from observations that actin in profilin-actin crystals is organized around a ribbon motif (r-actin), which we interpret to be an untwisted, extended form of the helical filamentous form of actin (h-actin) (7). In the transformation of actin from the helical to the ribbon form, the actin subunits undergo a 130 rotation as the segment extends by 8.25 A per subunit. It is presumed that the actin-actin intersubunit contacts are largely maintained during this transformation.The conclusion that r-actin and h-actin are related structures is based on a number of observations. First, growth of the r-actin form in the profilin-actin crystals appears to depend in a precise way on subtly shifting the competition for actin monomers away from h-actin formation toward entry into the growing crystal lattice. This strongly suggests that the same actin-actin bonds are used in both r-actin and h-actin. Second, x-ray diffraction shows clearly that crystals can be transformed into semicrystalline fibrous assemblies by replacing the bathing medium with solutions known to induce...

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“…It is known that the 6th ALL (the most prominent actin-based reflection in the small-angle area) is enhanced by ∼ 10% upon activation by calcium binding alone [7][8][9][10] and by up to 50% by calcium and myosin binding. [10][11][12][13] This enhancement does not accompany a peak shift towards the meridian and is therefore ascribed to the structural change of individual actin monomers (if the enhancement is due to myosin binding, the peak of the reflection should shift towards the meridian because of the increased radius of the thin filament; see Refs. [6][7][8][12][13][14].…”

Section: Introductionmentioning

confidence: 99%

“…[6][7][8][12][13][14]. Time-resolved X-ray diffraction studies report that the structural change occurs earlier than isometric force development 6,11 with a greater rate constant, and its role in the cooperative activation process of thin filament has been suggested. 10,15 Like vertebrate skeletal muscle, the insect flight muscle (IFM) is cross-striated as are all other muscles in the insect body.…”

Section: Introductionmentioning

confidence: 99%

Evidence for Unique Structural Change of Thin Filaments upon Calcium Activation of Insect Flight Muscle

Iwamoto

2009

Journal of Molecular Biology

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Time-resolved x-ray diffraction studies on the intensity changes of the 5.9 and 5.1 nm actin layer lines from frog skeletal muscle during an isometric tetanus using synchrotron radiation

Cited by 40 publications

References 9 publications

Stiffness changes in frog skeletal muscle during contraction recorded using ultrasonic waves.

Stiffness changes in frog skeletal muscle during contraction recorded using ultrasonic waves.

Actin as the generator of tension during muscle contraction.

Evidence for Unique Structural Change of Thin Filaments upon Calcium Activation of Insect Flight Muscle

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