Kayamori Taisuke, Miyake Norihito, Akiyama Nao, Aimi Momoko, Wakayama Jun'ichi, Kunioka Yuki, Yamada Takenori
Department of Physics (Biophysics Section), Faculty of Science, Tokyo University of Science, Shinjuku-ku, Tokyo 162-8601, Japan.
Cell Struct Funct. 2006;31(2):135-43. doi: 10.1247/csf.06017. Epub 2006 Nov 17.
The mechanical strength of sarcomere structures of skeletal muscle was studied by rupturing single myofibrils of rabbit psoas muscle by submicromanipulation techniques. Microbeads coated with alpha-actinin were attached to the surface of myofibrils immobilized to coverslip. By use of either optical tweezers or atomic force microscope, the attached beads were captured and detached from the myofibrils. During the detachment of the beads, the actin filaments bound specifically to the beads were peeled off from the bulk structures of myofibrils, thus rupturing the peripheral components of the myofibrils bound to the actin filaments. By analyzing the ruptures thus produced in various myofibril preparations, it was found that the sarcomere structure of myofibrils is maintained by numerous molecular components having the mechanical strength sufficient to sustain the contractile force produced by the actomyosin system. The present techniques could be applied to study the mechanical strength of cellular organelles containing actin filaments as their component.
通过亚显微操作技术使兔腰大肌的单个肌原纤维断裂，研究骨骼肌肌节结构的机械强度。将包被有α - 辅肌动蛋白的微珠附着于固定在盖玻片上的肌原纤维表面。使用光镊或原子力显微镜，捕获并从肌原纤维上分离附着的微珠。在微珠分离过程中，与微珠特异性结合的肌动蛋白丝从肌原纤维的整体结构上剥离，从而使与肌动蛋白丝结合的肌原纤维外周成分断裂。通过分析在各种肌原纤维制剂中产生的断裂情况，发现肌原纤维的肌节结构由众多具有足够机械强度以维持肌动球蛋白系统产生的收缩力的分子成分维持。本技术可应用于研究以肌动蛋白丝为成分的细胞器的机械强度。
