Lees-Miller J P, Heeley D H, Smillie L B
Department of Biochemistry, University of Alberta, Edmonton, Canada.
Biochem J. 1987 Jun 15;244(3):705-9. doi: 10.1042/bj2440705.
Using a rabbit polyclonal-antibody preparation directed against the chicken gizzard protein, we demonstrated by immunoblotting the presence of the 22 kDa protein (SM22) in a variety of chicken smooth-muscle-containing organs, including uterus, intestine, gizzard, oesophagus and aorta. Protein SM22 was present in only trace amounts in brain, liver and heart, and could not be detected in chicken breast muscle. The antibody preparation did not cross-react with extracts of bovine aorta. However, the presence of SM22 as a major component in bovine aorta and pig carotid was demonstrated by its co-migration with the purified chicken gizzard protein on one- and two-dimensional polyacrylamide electrophoretic gels. Its molar abundance relative to actin was estimated to be 0.9:6.0 and 1.4:6.0 for bovine aorta and pig carotid respectively. Like the chicken gizzard protein, it separates on pH-gradient electrophoresis into at least three variants, alpha, beta and gamma, with similar apparent Mr. Purification of the aorta SM22 showed it to have a similar amino acid composition to the chicken gizzard protein. We conclude that SM22 is widely distributed and an abundant and unique protein component of smooth-muscle tissues of birds and mammals.
使用针对鸡砂囊蛋白制备的兔多克隆抗体，我们通过免疫印迹法证明，在包括子宫、肠道、砂囊、食道和主动脉在内的多种含有鸡平滑肌的器官中存在22 kDa蛋白（SM22）。蛋白SM22在脑、肝和心脏中仅微量存在，在鸡胸肌中无法检测到。该抗体制剂与牛主动脉提取物无交叉反应。然而，通过在一维和二维聚丙烯酰胺电泳凝胶上与纯化的鸡砂囊蛋白共迁移，证明了SM22是牛主动脉和猪颈动脉中的主要成分。牛主动脉和猪颈动脉中其相对于肌动蛋白的摩尔丰度估计分别为0.9:6.0和1.4:6.0。与鸡砂囊蛋白一样，它在pH梯度电泳中分离为至少三种变体，α、β和γ，具有相似的表观分子量。主动脉SM22的纯化显示其氨基酸组成与鸡砂囊蛋白相似。我们得出结论，SM22广泛分布，是鸟类和哺乳动物平滑肌组织中丰富且独特的蛋白质成分。
