Pernelle J J, Righetti P G, Wahrmann J P, Herve B
Institut de Pathologie et Biologie, Cellulaires et Moléculaires, Paris.
Electrophoresis. 1990 Apr;11(4):325-32. doi: 10.1002/elps.1150110411.
Previous studies using two-dimensional gel electrophoresis have described adult and fetal isoforms of skeletal muscle myosin light chains (MLC). They have also revealed an embryo-specific light chain (LC1emb), apparently absent in most adult skeletal muscles. In order to characterize more thoroughly the MLC family, we have analyzed the MLCs from human skeletal muscle at different developmental stages using a two-dimensional electrophoresis technique with an immobilized pH gradient in the first dimension. The high resolution of this novel technique, resolving components which in isoelectric points are less than or equal to 0.01 pH, combined with sensitive silver staining, has allowed us to identify four phosphorylatable isoforms of MLC2: two slow-myosin light chains (MLC2Sa and b), two fast myosin light chains (MLC2Fa and b), and their phosphorylated counterparts: MLC2SaP and bP, MLC2FaP and bP. The following major modifications during development were observed: (i) The embryonic LC (LC1emb) persists up to at least 26 weeks of fetal life. (ii) The polymorphism of LC2 is already evident at 10 weeks of development but only the nonphosphorylated forms of LC2S and LC2F seem to be present. The LC2Fa form is predominant. As early as 26 weeks of fetal life, the 4 phosphorylated forms are detected. In the adult, LC2Fb is a minor component. (iii) LC3F (fast) is already expressed at an early embryonic stage (10 weeks).
以往使用二维凝胶电泳的研究已描述了骨骼肌肌球蛋白轻链（MLC）的成人及胎儿异构体。这些研究还揭示了一种胚胎特异性轻链（LC1emb），在大多数成人骨骼肌中显然不存在。为了更全面地表征MLC家族，我们使用了一种在第一维具有固定pH梯度的二维电泳技术，分析了不同发育阶段的人骨骼肌中的MLC。这种新技术的高分辨率能够分辨等电点小于或等于0.01 pH的成分，再结合灵敏的银染法，使我们能够鉴定出MLC2的四种可磷酸化异构体：两种慢肌肌球蛋白轻链（MLC2Sa和b）、两种快肌肌球蛋白轻链（MLC2Fa和b），以及它们的磷酸化对应物：MLC2SaP和bP、MLC2FaP和bP。在发育过程中观察到以下主要变化：（i）胚胎轻链（LC1emb）至少持续存在至胎儿期26周。（ii）LC2的多态性在发育10周时就已明显，但似乎仅存在LC2S和LC2F的非磷酸化形式。LC2Fa形式占主导。早在胎儿期26周时，就检测到了4种磷酸化形式。在成人中，LC2Fb是次要成分。（iii）LC3F（快）在胚胎早期（10周）就已表达。
