Güth K
Biophys Struct Mech. 1980;6(2):81-93. doi: 10.1007/BF00535746.
The degree of polarization of the intrinsic tryptophan fluorscence of glycerinated simgle muscle fibres or fibre bundles (rabbit psoas or dorsal longitudinal muscle of Lethocerus maximus) was measured: a) With sufficiently high (15 mM) ATP concentration or when an ATP regenerating system was used no difference in the degree of polarization of a contracting and a relaxed muscle was detected, whereas a distinct difference was detected between the relaxed and the rigor state. In contrast a distinct difference between the relaxed and contracting state was obtained at low ATP concentrations (5 mM). This difference is interpreted to be caused by an ATP-free core (rigor core) in the centre of the fibre. b) No change in the polarization degree was detected after a rapid release of the contracting muscle. c) In rigor state no difference in the degree of polarization of the tryptophan fluorescence was observed in the presence or absence of AMPPNP (concentration 0.5 mM). These findings and the lack of difference between the polarization degree of the contracting and the relaxed muscle is interpreted to indicate that the polarization degree of the tryptophan fluorescence is not sensitive to the orientation of the cross bridges, or that the cross bridges do not rotate.
对甘油处理的单个肌纤维或纤维束（兔腰大肌或大仰蝽背纵肌）中内在色氨酸荧光的偏振度进行了测量：a）在足够高的ATP浓度（15 mM）下或使用ATP再生系统时，未检测到收缩肌和松弛肌偏振度的差异，而在松弛状态和僵直状态之间检测到明显差异。相比之下，在低ATP浓度（5 mM）下，松弛状态和收缩状态之间存在明显差异。这种差异被解释为由纤维中心的无ATP核心（僵直核心）引起。b）收缩肌快速松弛后，未检测到偏振度的变化。c）在僵直状态下，无论有无AMPPNP（浓度0.5 mM），色氨酸荧光的偏振度均未观察到差异。这些发现以及收缩肌和松弛肌偏振度之间缺乏差异被解释为表明色氨酸荧光的偏振度对横桥的取向不敏感，或者横桥不旋转。
