Mecham R P, Hinek A, Entwistle R, Wrenn D S, Griffin G L, Senior R M
Department of Medicine, Jewish Hospital, Washington University Medical Center, St. Louis, Missouri 63110.
Biochemistry. 1989 May 2;28(9):3716-22. doi: 10.1021/bi00435a014.
Elastin binding proteins from plasma membranes of elastin-producing cells were isolated by affinity chromatography on immobilized elastin peptides. Three proteins of 67, 61, and 55 kDa were released from the elastin resin by guanidine/detergent, soluble elastin peptides, synthetic peptide VGVAPG, or galactoside sugars, but not by synthetic RGD-containing peptide or sugars not related to galactose. All three proteins incorporated radiolabel upon extracellular iodination and contained [3H]leucine following metabolic labeling, confirming that each is a synthetic product of the cell. The 67-kDa protein could be released from the cell surface with lactose-containing buffers, whereas solubilization of the 61- and 55-kDa components required the presence of detergent. Although all three proteins were retained on elastin affinity columns, the 61- and 55-kDa components were retained only in the presence of 67-kDa protein, suggesting that the 67-kDa protein binds elastin and the 61- and 55-kDa proteins bind to the 67-kDa protein. We propose that the 67-, 61-, and 55-kDa proteins constitute an elastin-receptor complex that forms a transmembrane link between the extracellular matrix and the intracellular compartment.
通过固定化弹性蛋白肽的亲和色谱法,从产生弹性蛋白的细胞膜中分离出弹性蛋白结合蛋白。67 kDa、61 kDa和55 kDa的三种蛋白质可通过胍/去污剂、可溶性弹性蛋白肽、合成肽VGVAPG或半乳糖苷糖从弹性蛋白树脂中释放出来,但不能通过含RGD的合成肽或与半乳糖无关的糖释放。所有这三种蛋白质在细胞外碘化时都会掺入放射性标记,并在代谢标记后含有[3H]亮氨酸,证实每种都是细胞的合成产物。67 kDa的蛋白质可以用含乳糖的缓冲液从细胞表面释放出来,而61 kDa和55 kDa成分的溶解则需要去污剂的存在。尽管所有这三种蛋白质都保留在弹性蛋白亲和柱上,但61 kDa和55 kDa的成分仅在67 kDa蛋白质存在时才保留,这表明67 kDa的蛋白质结合弹性蛋白,而61 kDa和55 kDa的蛋白质则结合到67 kDa的蛋白质上。我们提出,67 kDa、61 kDa和55 kDa的蛋白质构成一个弹性蛋白受体复合物,该复合物在细胞外基质和细胞内区室之间形成跨膜连接。