POLARIZATION OF FLUORESCENTLY LABELED MYOSIN SUBFRAGMENT-1 FULLY OR PARTIALLY DECORATING MUSCLE-FIBERS AND MYOFIBRILS
POLARIZATION OF FLUORESCENTLY LABELED MYOSIN SUBFRAGMENT-1 FULLY OR PARTIALLY DECORATING MUSCLE-FIBERS AND MYOFIBRILS
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DOI：
10.1016/s0006-3495(93)81161-5
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发表时间：
1993-09-01
影响因子：
3.4
通讯作者：
BOREJDO, J
中科院分区：
文献类型：
--
作者：
ANDREEV, OA;ANDREEVA, AL;BOREJDO, J
将荧光标记的肌球蛋白头（S1）以各种浓度加入肌纤维和肌原纤维中。染料的吸收偶极相对于F-肌动蛋白的轴的取向计算从偏振的荧光，这是通过一种新的方法从视频图像的肌肉测量。在这种方法中，从肌肉发出的光被双折射晶体分成两个不重叠的图像：第一个图像是用平行于肌肉轴方向的偏振光创建的，第二个图像是用垂直于肌肉轴方向的偏振光创建的。通过高灵敏度摄像机记录图像，并从两个图像的相对强度计算偏振。该方法允许测量的荧光偏振从单肌原纤维灌注低浓度的S1标记的染料。取向也通过荧光检测线性二色性来测量。当用高浓度的S1（摩尔比S1：肌动蛋白I带等于1）和用低浓度的S1（摩尔比S1：肌动蛋白I带等于0.32）灌注时，肌肉的取向是不同的。结果支持我们先前的建议，S1可以形成两个不同的严格的复合物与F-肌动蛋白取决于S1：肌动蛋白的摩尔比。
Fluorescently labeled myosin heads (S1) were added to muscle fibers and myofibrils at various concentrations. The orientation of the absorption dipole of the dye with respect to the axis of F-actin was calculated from polarization of fluorescence which was measured by a novel method from video images of muscle. In this method light emitted from muscle was split by a birefringent crystal into two nonoverlapping images: the first image was created with light polarized in the direction parallel to muscle axis, and the second image was created with light polarized in the direction perpendicular to muscle axis. images were recorded by high-sensitivity video camera and polarization was calculated from the relative intensity of both images. The method allows measurement of the fluorescence polarization from single myofibril irrigated with low concentrations of S1 labeled with dye. Orientation was also measured by fluorescence-detected linear dichroism. The orientation was different when muscle was irrigated with high concentration of S1 (molar ratio S1:actin in the I bands equal to 1) then when it was irrigated with low concentration of S1 (molar ratio S1:actin in the I bands equal to 0.32). The results support our earlier proposal that S1 could form two different rigor complexes with F-actin depending on the molar ratio of S1:actin.