AN ELASTIC PROTEIN IN CELL OF AORTA SMOOTH MUSCLE

众所周知，一种高分子质量的弹性蛋白(连接素：3000 kDa)存在于横纹肌中，而不存在于平滑肌中。用0.1M磷酸二氢钠缓冲液(pH 6.6)提取牛、鸡肌主动脉组织中的900 kDa蛋白质。提取液经35 mM磷酸二氢钾缓冲液(pH 7.0)透析后，用DEAE柱层析从35~60 mm磷酸盐缓冲液中梯度洗脱，部分纯化。从鸡胆提纯的蛋白与900 kDa蛋白的多克隆抗体发生交叉反应。抗体与鸡主动脉和肌胃平滑肌提取液中的900 kDa条带反应，经旋转阴影后，在电子显微镜下观察纯化的蛋白质。900 kDa蛋白质的分子形状很长，非常灵活，类似于脊椎动物的横纹弹性蛋白(Connectn)。目前正在进行cDNA测序工作。

It is well known that a high melecular weight elastic protein, (connectin : 3,000 kDa) is present in striated muscle, but not in smooth muscle. However, a 900 kDa protein was detected by 2-6% SDS gel electrophoresis in smooth muscle.The 900 kDa protein was extracted from aorta of bovine or chicken gizzard smooth muscle, with 0.1 M sodium phosphate buffer (pH 6.6). After the extract was dialyzed against 35 mM potassium phosphate buffer (pH 7.0), the protein was partially purified with DEAE column chromatography by gradient elution from 35 to 60 mM phosphate buffer. The purified protein from chicken gizzard crossreacted with the plolyclonal antibodies to the 900 kDa protein. The antibodies reacted with the 900 kDa band in the total SDS extract of both chicken aorta and gizzard smooth muscle.The purified protein was observed under an electron microscope after rotary shadowing. The molecular shape of 900 kDa protein was long and very flexible, similar to vertebrate striated elastic protein (connectn).Now cDNA sequence work is under way.