Lännergren J, Hoh J F
Proc R Soc Lond B Biol Sci. 1984 Sep 22;222(1228):401-8. doi: 10.1098/rspb.1984.0072.
An analysis has been performed of the native myosin isoenzyme composition of isolated skeletal muscle fibres from Xenopus laevis with well-defined isotonic contraction properties. Fast twitch 'white' (type 1) fibres contained three isomyosins; fast twitch 'red' (type 2) fibres showed two major myosin bands with migration velocities very similar to those of the two slower bands in type 1. Slow twitch (type 3) fibres yielded a single, slowly migrating band as did slow tonic (type 5) fibres, whereas the myosin from type 4 (very slow twitch, 'intermediate') fibres migrated with a somewhat higher mobility. The results suggest that amphibian skeletal muscle may possess the principal fibre types found in mammals and birds.
对具有明确等张收缩特性的非洲爪蟾离体骨骼肌纤维的天然肌球蛋白同工酶组成进行了分析。快速收缩的“白色”（1型）纤维含有三种异肌球蛋白；快速收缩的“红色”（2型）纤维显示出两条主要的肌球蛋白带，其迁移速度与1型纤维中两条较慢的带非常相似。慢收缩（3型）纤维和慢强直性（5型）纤维一样，产生一条单一的、迁移缓慢的带，而来自4型（非常慢收缩的“中间型”）纤维的肌球蛋白迁移时具有稍高的迁移率。结果表明，两栖动物的骨骼肌可能具有在哺乳动物和鸟类中发现的主要纤维类型。
