Franchi L L, Murdoch A, Brown W E, Mayne C N, Elliott L, Salmons S
Department of Anatomy, Medical School, University of Birmingham, UK.
J Muscle Res Cell Motil. 1990 Jun;11(3):227-39. doi: 10.1007/BF01843576.
Immunogold labelling was used to study the distribution of newly synthesized slow muscle myosin (SM) at the ultrastructural level as it replaced fast muscle myosin (FM) in rabbit muscles undergoing stimulation-induced type transformation. Control fast muscle was labelled strongly with antibody to FM and control slow muscle with antibody to SM; label was confined to the A-band. Well-defined differences in the distribution of label within the A-band suggested that the monoclonal antibodies used corresponded to epitopes on different parts of the myosin molecule; this was confirmed by Western blots of subfragments prepared from FM and SM. After 4 weeks of continuous stimulation at 10 Hz, fibres of the tibialis anterior muscle reacted with antibodies to both isoforms; after 6 weeks, labelling was obtained only with antibody to SM. After a 7-week period of stimulation and 3 further weeks of recovery, fibres again reacted with both antibodies. In all positively-labelled sections, the distribution of gold particles was characteristic of the antibody and independent of the origin or history of the fibres. This observation supports the conclusion that newly synthesized myosin is capable of being incorporated throughout the length and cross-section of the A-band.
免疫金标记技术用于在超微结构水平研究新合成的慢肌肌球蛋白（SM）的分布，该过程发生在兔肌肉因刺激诱导型转变而使快肌肌球蛋白（FM）被取代时。对照快肌用抗FM抗体强烈标记，对照慢肌用抗SM抗体标记；标记局限于A带。A带内标记分布存在明确差异，这表明所用单克隆抗体对应于肌球蛋白分子不同部位的表位；从FM和SM制备的亚片段的蛋白质免疫印迹证实了这一点。在10Hz连续刺激4周后，胫前肌纤维与两种同工型的抗体均发生反应；6周后，仅用抗SM抗体获得标记。在7周刺激期和随后3周恢复期后，纤维再次与两种抗体发生反应。在所有阳性标记切片中，金颗粒的分布具有抗体特异性，且与纤维的来源或经历无关。这一观察结果支持以下结论：新合成的肌球蛋白能够整合到A带的全长和横截面积中。
