Maéda Y
Eur J Biochem. 1978 Sep 15;90(1):113-21. doi: 10.1111/j.1432-1033.1978.tb12581.x.
Birefringence of the I-band of glycerinated myofibrils of the walking legs of the crab, Plagusia dentipes was examined by rectified polarization optics. The coefficient of birefringence of the I-band was estimated to be 1.64 X 10(-3), which attained about 60% of the birefringence of the H-zone. The number ratio of thin filaments to thick filaments in the A-band was six according to electron microscopy and the spacing between neighbouring thick filaments was about 56 nm according to X-ray diffraction. From these values, the protein concentration in the I-band was estimated to be 91 mg/ml. Thus, the birefringence of the I-band was found to be of the same order as the birefringence of the reconstituted thin filaments oriented by flow at the same protein concentration. The ratio of protein concentration in the I-band to that in the H-zone was determined by interferometry. The ratio of birefringence of the I-band to that of the H-zone per unit protein concentration was found to be about 0.9, which was comparable to the ratio of birefringence of the thin filaments and thick filaments in solution. The imbibition experiment showed that 70% of the total birefringence of the I-band is form birefringence and remaining 30% comes from intrinsic birefringence.
利用整流偏振光学方法研究了齿斑方蟹步足甘油化肌原纤维I带的双折射。I带的双折射系数估计为1.64×10⁻³，约为H带双折射的60%。根据电子显微镜观察，A带中细肌丝与粗肌丝的数量比为6，根据X射线衍射，相邻粗肌丝之间的间距约为56nm。根据这些值，估计I带中的蛋白质浓度为91mg/ml。因此，发现I带的双折射与相同蛋白质浓度下通过流动取向的重组细肌丝的双折射处于同一量级。通过干涉测量法测定了I带与H带中蛋白质浓度的比值。发现I带与H带每单位蛋白质浓度的双折射比值约为0.9，这与溶液中细肌丝和粗肌丝的双折射比值相当。吸水实验表明，I带总双折射的70%来自形态双折射，其余30%来自固有双折射。
