摘要
从整块肌肉抽提的肌球蛋白,其轻链类型因肌肉收缩的快慢而有区别,即快肌的肌球蛋白有三条轻链,慢肌的肌球蛋白只有二条轻链(Sarker等,1971;Lowey和Risby,1971),它们分别属于不同的肌球蛋白同功酶,这在鸡(Hoh,1978)和兔(Hoh,1979)都是这样。另外,在神经肌肉的发育过程中,一旦有了神经控制,便使起初只合成快型轻链的肌肉,逐步向合成慢型轻链的慢肌分化(Rubinstein和Kelly,1978)。然而,快肌和慢肌不同的轻链图谱特征,是否也表现在肌纤维的快慢类型上呢?这很少见到报道。我们曾观察到单肌纤维的肌球蛋白有二个成份,它们之间的比值和各自的电泳迁移率可以作为区别二类不同单肌纤维的特征(章生艮、任惠民,1983)。我们认为既然快肌纤维和慢肌纤维的肌球蛋白成份各有特征,那末,单肌纤维的肌球蛋白轻链图谱,当然也应该能反映单肌纤维的快、慢类型了。本文目的就是利用毛细管凝胶电泳对单肌纤维的轻链分析,来探讨这个问题。
According to the analysis on light chain pattern of single fibers,there were one third of fibers in rat soleus muscle which had a distinct staining band at the position of LC3,while the remaining fibers did not show such band by present method due to its minute quantity.No matter whether or not LC3 appeared,the electrophorctic patterns of fiber proteins between Sol and EDL were completely different,including the differences of molecular weights of LQ,LC2 and the distance travelled along the gel between LC1 and tropomyosin of fibers of the two muscles.Experiments have been performed to see if LC3 exists in each fiber of soleus muscle.We deduced it by analyzing randomly three fibers in one electrophorctic gel to show the chance of appearance of LC3 by simple probability calculation and a great exceed(89%)over the’theoretical’value(67%)in probability was achieved.For the same purpose,we also analyzed guinea pig soleus which was known to have pure slow fibers,and conform to that,100%of fibers tested contained LC3;and finally 56%of cat soleus fibers was found to contain LC3 whose appcarncc were clearly related to their intensity of protein staining on clectrophoretic gels.Attempts have also been made to explore the corelation between light chain characteristics and ATPasc activity of fibers.Preliminary results indicated that there were no such parallel relationship.
作者
任惠民
陈秀芳
章生艮
Ren Huimin;Chen Xiufang;Zhang Shenggen(Shanghai Institute of Physiology,Academia Sinica)
