RABBIT SKELETAL MYOSIN ISOENZYMES FROM FETAL, FAST-TWITCH AND SLOW-TWITCH MUSCLES
RABBIT SKELETAL MYOSIN ISOENZYMES FROM FETAL, FAST-TWITCH AND SLOW-TWITCH MUSCLES
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DOI：
10.1038/280321a0
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发表时间：
1979-01-01
期刊：
影响因子：
64.8
通讯作者：
YEOH, GPS
中科院分区：
文献类型：
--
作者：
HOH, JFY;YEOH, GPS
通常认为，脊椎动物快抽动和慢抽动肌肉中的肌球蛋白在结构上是1-4，在免疫化学上是5-8，并以几种同工酶9-14的形式存在。一些作者认为它在轻链组成和组织化学的基础上与成人快抽动肌球蛋白相同。其他人认为这可能是快抽动和慢抽动肌球蛋白的混合体。还有4，17人坚持认为这是一种不同于成人肌球蛋白的不同于初级结构的胎儿肌球蛋白形式。在本报告中，我们发现：(1)新生兔和成年兔快抽动肌中肌球蛋白以轻链组成不同的三种不同的同工酶形式存在；(2)新生肌球蛋白重链的二维肽图与快抽动肌球蛋白和慢抽动肌球蛋白的二维肽图不同。这些结果清楚地证明了发育中的哺乳动物肌肉中存在胎儿肌球蛋白同工酶，并解决了文献中明显的矛盾。
IT is generally accepted that myosin in vertebrate fast-twitch and slow-twitch muscles is structurally1–4and immunochemically5–8distinct and exists in several isoenzymatic forms9–14. The nature of myosin in developing mammalian skeletal muscles is controversial. Some authors15,16consider it to be identical to adult fast-twitch myosin on the basis of light-chain composition and histochemistry. Others8suggest that it may be a mixture of fast-twitch and slow-twitch myosins. Still others4,17maintain it is a distinct fetal form of myosin differing in primary structure from adult myosins. In this report we show that (1) myosin in both neonatal and adult fast-twitch muscles of the rabbit exists in three electrophoretically distinct isoenzymatic forms which differ in light-chain composition, and (2) the two-dimensional peptide map of the heavy chains of neonatal muscle myosin is distinct from maps of both fast-twitch and slow-twitch myosins. These results clearly establish the existence of fetal myosin isoenzymes in developing mammalian muscles and resolve apparent contradictions in the literature.