AN ELASTIC PROTEIN IN CELL OF AORTA SMOOTH MUSCLE

众所周知，一种高分子量的弹性蛋白（连接蛋白：3000 kDa）存在于横纹肌中，而不存在于平滑肌中。2-6% SDS凝胶电泳在平滑肌中检测到900 kDa蛋白。用0.1 M磷酸钠缓冲液（pH 6.6）从牛或鸡胗平滑肌主动脉中提取900 kDa蛋白。提取液在35 mM磷酸钾缓冲液（pH 7.0）中透析后，用DEAE柱层析在35 - 60 mM磷酸缓冲液中梯度洗脱部分纯化蛋白。纯化的鸡胗蛋白与900 kDa蛋白的多克隆抗体发生交叉反应。抗体与鸡主动脉和砂囊平滑肌总SDS提取液中900 kDa条带发生反应。转影后在电子显微镜下观察纯化蛋白。900 kDa蛋白的分子形状较长，具有很强的柔韧性，与脊椎动物的条纹弹性蛋白（connectn）相似。现在cDNA序列工作正在进行中。

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.