• 생명과학회지
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• 제9권6호
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• pp.646-652
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• 1999

The effect of temperature on the structure change of the SH of myosin head have been investigated with improved resolution by x-ray diffraction using synchrotron radiation. The movement of myosin head and conformational change of contractile molecules were occurred in the muscle contraction. IASL (iodo acetamide) and MSL (maleimide) disordered the orderly helix arrangement of myosin in the rest state of spin level. The temperature effect on the structure change was great at the UL in the equatorial reflection. But those of IASL and MSL were minor. Equatorial reflection (10, 11) change inferred that myosin head was moved to the vicinity of actin filament by temperature change (from $25^{\circ}C$ to $0^{\circ}C$) at UL, but spin level was not changed. The intensity change of 143 $\AA$ and 72 $\AA$ could offer information of the mass profection of population of myosin heads along the filament axis. The slope of intensity profile of the mass profection of 143$\AA$ and reflection of MSL is appeared sharply and those of UL and IASL were not changed. The decrease of MSL actin reflection at 51 $\AA$ and 59 $\AA$ in the actin reflection change refers that the shifted myosin head binds a certain actin or changes an actin structure. From these results, we could conclude that IASL and MSL were spin labeled on SH of myosin head and disordered the helix arrangement of actin.

• 생명과학회지
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• 제8권6호
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• pp.681-686
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• 1998

이상의 결과로부터 spin lavel의 영향은 IASL, MSL은 이완상태 myosin head의 규칙적인 나선 배열은 흐트러진다. 특히 IASL은 효과가 크다. 적도반사의 변화로부터 myosin head는 spin label하는 것에 의해 actin filament 근방에 이동해 있다는 것을 알 수 있었다. 215 $\AA$ 반사의 감소는 spin lavel에 의한 myosin의 143 $\AA$주기성을 더욱 강하게 해 준다. 143 $\AA$, 72 $\AA$의 거동은 filament축으로부터 투영한 구조를 반영하기 때문에 IASL에는 143 $\AA$ 주기의 밀도분포가 완만하게 되어 있다는 것을 나타내고, MSL에는 143 $\AA$ 분포가 올라와 있다는 것을 나타낸다. actin 반사변화에서 MSL의 actin반사의 증가는 이동한 myosin head가 어떤 actin과 결합하였거나, spin lavel의 영향으로 actin의 구조가 변화되었다. 한편, IASL은 actin반사를 감소 시키기 때문에 myosin head의 결합을 하지 않았다. 결론적으로, 이것은 actin의 SH기에도 spin label되어 actin의 나선 구조가 크게 흐트러짐을 알 수 있었다

• 한국응용과학기술학회지
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• 제22권1호
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• pp.84-90
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• 2005

IASL(iodo acetamide) and MSL(maleimide) disordered the orderly helix arrangement of myosin in the rest state of spin level. Especially the effect of IASL was great. Equatorial refiection(10,11) change inferred that myosin head was moved to the vicinity of actin filament by spin level. The intensity change of 143${\AA}$ and 72${\AA}$ could offer information of the mass projection of population of myosin heads along the :filament axis. The slope of intensity profile of the mass projection of 143${\AA}$ and reflection of IASL is appeared and that of MSL is appeared sharply. The decrease of 215${\AA}$ reflection intensity is appeared the periodical characteristic of 143${\AA}$ reflection by spin label. The raise of MSL actin reflection at 51${\AA}$ and 59${\AA}$ in the actin reflection change refers that the shifted myosin head binds a certain actin or changes an actin structure by spin label effect. Because iodo acetamide has a tendency to decease the actin reflection, actin dose not bind myosin head. From this result, we could conclude that LASL and MSL are spin labeled on SH of myosin head and disordered the helix arrangement of actin.

• 한국응용과학기술학회지
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• 제20권3호
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• pp.268-273
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• 2003

IASL(iodo acetamide spin label) and MSL(maleimide spin label) disordered the orderly helix arrangement of myosin in the rest state of spin level. Especially the effect of IASL was great. The muscle was isometrically tetanized with three trains of 3ms pulses every 50ms between $5^{\circ}C$ with $25^{\circ}C$. Equatorial reflection change inferred that myosin head was moved to the vicinity of actin filament by spin level. The intensity change of $143{\AA}$ and $72{\AA}$ could offer information of the mass projection of population of myosin head along the filament axis. The slope of intensity profile of the mass projection of $143{\AA}$ and reflection of IASL is appeared and that of MSL is appeared sharply. The decrease of $215{\AA}$ reflection intensity the periodical character of $143{\AA}$ reflection by spin label. The raise of MSL actin reflection at $51{\AA}$ and $59{\AA}$ in the actin reflection change refers that the shifted myosin head binds a certain actin or changes an actin structure by spin label effect. Because iodo acetamide has a tendency to decease the actin reflection, actin dose not bind myosin head. From this result, we can conclude that IASL and MSL are spin labeled on SH of myosin head and disordered the helix arrangement of actin.

• 생명과학회지
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• 제8권4호
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• pp.373-380
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• 1998

A considerable change observed in X-ray diffraction during the muscle contraction was that the movement of myosin head and conformational change of contractile monecules were occurred in the muscle contraction. Time slice requires tension peak after the onset of stimulation and the height of tension peak depends on the number of twitch cycle. The intensity of I$_{11}$, I$_{10}$, 143${\AA}$ reflection is measured with 5ms time resolution and is recorded in isometric tension. The peak height of I$_{11}$ and 143${\AA}$ intensity is changed after the onset of a stimulation I$_{i}$, and the length of twitch is shortened by successive twitches in the case of stimulation TI$_{i}$. On the other hand, the peak height of I$_{11}$ and 215${\AA}$ intensity starts to decrease at the 1st twitch and remains constant at low peak hight without appreciable recovery during the contraction term. In the case of uccessive twitch stimulation, the myosin heads of muscle are once moved from their resting position and never returned to their initial position.

• 한국응용과학기술학회지
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• 제24권1호
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• pp.61-66
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• 2007

X-ray diffraction studies have been made to investigate the effects of binding of ADP, ADP+Vi, ADP+AIF4, $ADP+BeF_3$ on the structure of glycerinated rabbit skeletal muscle in the rigor state. Although these phosphate analogs are known to bind actively cycling myosin heads, it is not clear whether they can bind to the attached heads in the rigor muscle. We have found that these analogs can bind to the myosin heads attached to actin filaments in the rigor state. The present results indicate that (1) bound myosin heads altered their conformation in the proximal end toward the plane perpendicular to the fiber axis when MgADP bound to them, and (2) myosin heads were dissociated substantially (up to 50%) from actin filaments but still remained in the vicinity of actin filaments when MgADP and metallofluorides (AIF4 and BeF3) or vanadate bound to them. We detected new conformations of myosin heads attached to actin filaments when they had MgADP or ADP.Pi analogs. We report here these findings on the effects of MgADP and MgADP+phosphate analogs to the rigor crossbridges.

• 한국응용과학기술학회지
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• 제24권4호
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• pp.362-368
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• 2007

To study the relationship between elementary biochemical states and structural states of the actomyosin crossbridges in muscle, the effects of binding of MgADP to myosin heads in the rigor muscle were examined by X-ray diffraction using synchrotron radiation. X-ray diffraction studies have been made to investigate the effects of binding of ADP on the structure of glycerinated rabbit skeletal muscle in the rigor state. The intensity increase was accompanied by a slight but distinct decrease in the 5.9 am layer-line intensity close to the meridian. These results strongly suggest that myosin heads altered their attached conformation in the proximal end toward the plane perpendicular to the fiber axis when MgADP was bound to them. We found that the intensity of the 14.5 nm-based meridional reflections increase by 20-50% when MgADP was added to the rigor muscle in the presence of hexokinase and myokinase inhibitor.

• 한국응용과학기술학회지
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• 제21권2호
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• pp.182-189
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• 2004

On contraction of the muscles, marked changes in X-ray reflections are observed, suggesting that conformational changes of contractile molecules and the movement of myosin heads during muscle contraction. Time slice requires tension peak after the onset of stimulation and the height of tension peak depends on the number of twitch cycle. The muscles were stimulated by five successive stimuli at an interval of 80 ms started while the tension was still being exerted by the muscles. The intensity of $I_{11}$, $I_{10}$, $143{\AA}$ and $215{\AA}$ reflection measured with 5ms time resolution and is recorded in isometric tension. The peak height of $I_{11}$ and $143{\AA}$ intensity is changed after the onset of a stimulation $I_i$, and the length of twitch is shortened by successive twitches in the case of stimulation $T_i$. On the other hand, the peak height of In and $215{\AA}$ intensity starts to decrease at the 1st twitch and remains constant at low peak height without appreciable recovery during the contraction term. In the case of successive twitch stimulation, the myosin heads of muscle are once moved from their resting position and never returned to their initial position.

• 한국콘텐츠학회논문지
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• 제5권4호
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• pp.71-77
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• 2005

본 논문에서는 근육 분자막에서 일어나는 변화를 image plate에 의해 나타난 2차원 X선 회절상으로 구조분석 하였다. 그리고 자극장치로 분자막에 연속 전기자극을 가하여 장력발생의 시간적 변화에 미치는 영향을 규명하고자 하였다. 근육 수축 중에 X선 구조분석에 의해 관찰되어진 두드러진 변화는 근육수축을 하는 가운데 myosin head의 움직임과 수축분자의 변화가 관찰되었다. 연속자극에서의 근육은 충분히 활성화되었고, 이 시점에서 최대장력을 발생한다. 그러나 그 다음 이후의 수축에는 최대장력$(T_i-I_i)$이 거의 변화가 일어나지 않고 있다는 것을 알 수 있었다.

• 한국수산과학회지
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• 제27권4호
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• pp.327-334
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• 1994

치사 방법을 달리하여 치사한 넙치육을 $5^{\circ}C$에서 저장하면서 치사 방법이 육의 파괴강도의 변화에 미치는 원인을 규명하기 위하여, 근원섬유의 형태학적인 변화 그리고 근육의 조직학적인 변화에 대하여 검토한 결과를 요약하면 다음과 같다. 1. 육의 파괴강도의 상승은 전기 자극사에서 가장 빠르고 최대값도 높았으며, 마취사에서 파괴강도가 최대로 되는 시간이 가장 연장되었다. 2. 근원섬유의 형태학적인 변화는 즉살 직후에는 근절내의 A대, H대, I대 그리고 Z선이 확실히 구별되었으나, 즉살한 시료는 저장 10시간후에 A대 중앙부의 H대 구별이 화실하지 않았으며, I대 간격이 좁아졌음이 관찰되었다. 마취사시킨 시료는 저장 15시간후에도 A대 중앙부의 H대가 희미하게 관찰되었다. 한편 전기 자극사시킨 시료는 치사 직후에 A대 중앙부의 H대의 구별이 불가능하였으며 I대의 간격이 좁아져있었다. 3. 근육의 조직학적인 변화는, 즉살 직후에는 세포와 세포의 간격이 전혀 관찰되지 않았으나, 즉살 및 마취사에서는 각각 저장 15시간 및 24시간 후에 전체 세포 사이의 간격이 관찰되었다. 한편, 전기 자극사에서는 치사 직후에 세포 사이에 약간의 간격이 관찰되었을 뿐만 아니라. 저장 2.5시간후에 전체의 세포 사이에 간격이 넓어졌다. 이상의 결과로 부터, 사후 조기에 육의 파괴강도의 변화는 myosin과 actin의 결합에 의한 장력의 발생 및 세포외 matrix구조의 파괴와 깊은 관계가 있음을 알 수 있다.