Characterization of the myosin-based source for second-harmonic generation from muscle sarcomeres
Characterization of the myosin-based source for second-harmonic generation from muscle sarcomeres
复制标题
DOI：
10.1529/biophysj.105.071555
复制
发表时间：
2006-01-01
影响因子：
3.4
通讯作者：
Mohler, WA
中科院分区：
文献类型：
--
作者：
Plotnikov, SV;Millard, AC;Mohler, WA
几种生物学上重要的蛋白质结构在其天然环境中产生强二次谐波产生（SHG）。除了细胞和组织的高对比度光学切片之外，SHG成像还可以基于光学效应的物理约束提供详细的结构信息。在这项研究中，我们的特点，生化和光学分析，关键结构的基础SHG从复杂的肌肉肌节。SHG发射产生于含有厚的肌节的结构域。遗憾的是，即使在分化的肌细胞的新生肌节内。从分离的肌原纤维的SHG被取消提取肌球蛋白，但不受影响的去除或添加肌动蛋白。哀叹。此外，肌节SHG的极化依赖性不受肌球蛋白头域的比例或肌球蛋白头的取向的影响。通过拟合SHG偏振各向异性读数的理论响应曲线，我们找到了一个方向的元素谐波，以及对应的肌球蛋白杆α-螺旋沿着厚的间距。哀歌轴总之，这些数据表明，肌球蛋白杆结构域是从横纹肌产生SHG的关键结构。这项研究应指导解释的心脏和骨骼肌组织的各种生物医学应用的图像中的SHG对比。
Several biologically important protein structures give rise to strong second-harmonic generation (SHG) in their native context. In addition to high-contrast optical sections of cells and tissues, SHG imaging can provide detailed structural information based on the physical constraints of the optical effect. In this study we characterize, by biochemical and optical analysis, the critical structures underlying SHG from the complex muscle sarcomere. SHG emission arises from domains of the sarcomere containing thick. laments, even within nascent sarcomeres of differentiating myocytes. SHG from isolated myofibrils is abolished by extraction of myosin, but is unaffected by removal or addition of actin. laments. Furthermore, the polarization dependence of sarcomeric SHG is not affected by either the proportion of myosin head domains or the orientation of myosin heads. By fitting SHG polarization anisotropy readings to theoretical response curves, we find an orientation for the elemental harmonophore that corresponds well to the pitch of the myosin rod alpha-helix along the thick. lament axis. Taken together, these data indicate that myosin rod domains are the key structures giving SHG from striated muscle. This study should guide the interpretation of SHG contrast in images of cardiac and skeletal muscle tissue for a variety of biomedical applications.