Miles A J, Knutson J R, Skubitz A P, Furcht L T, McCarthy J B, Fields G B
Department of Laboratory Medicine, University of Minnesota, Minneapolis 55455, USA.
J Biol Chem. 1995 Dec 8;270(49):29047-50. doi: 10.1074/jbc.270.49.29047.
Tumor cell adhesion to the triple-helical domain of basement membrane (type IV) collagen occurs at several different regions. Cellular recognition of the sequence spanning alpha 1(IV)531-543 has been proposed to be independent of triple-helical conformation (Miles, A. J., Skubitz, A. P. N., Furcht, L. T., and Fields, G. B. (1994) J. Biol. Chem. 269, 30939-30945). In the present study, integrin interactions with a peptide analog of the alpha 1(IV)-531-543 sequence have been analyzed. Tumor cell adhesion (melanoma, ovarian carcinoma) to the alpha 1(IV)531-543 chemically synthesized peptide was inhibited by a monoclonal antibody against the alpha 3 integrin subunit, and to a lesser extent by monoclonal antibodies against the beta 1 and alpha 2 integrin subunits. An anti-alpha 5 monoclonal antibody and normal mouse IgG were ineffective as inhibitors of tumor cell adhesion to the peptide. Two cell surface proteins of 120 and 150 kDa bound to an alpha 1(IV)531-543 peptide affinity column and were eluted with 20 mM EDTA. When the eluted proteins were incubated with monoclonal antibodies against either the alpha 3 or beta 1 integrin subunit, proteins corresponding in molecular weight to alpha 3 and beta 1 integrin subunits were precipitated. No proteins were immunoprecipated with monoclonal antibodies against the alpha 2 or alpha 5 integrin subunits. Thus, the alpha 3 beta 1 integrin from two tumor cell types has been shown to bind directly to the alpha 1 (IV)531-543 peptide. The alpha 1(IV)531-543 peptide is the first collagen-like sequence that has been shown to bind the alpha 3 beta 1 integrin.
肿瘤细胞与基底膜（IV型）胶原蛋白的三螺旋结构域的黏附发生在几个不同区域。有人提出，对跨越α1(IV)531 - 543序列的细胞识别独立于三螺旋构象（迈尔斯，A. J.，斯库比茨，A. P. N.，弗希特，L. T.，以及菲尔兹，G. B.（1994年）《生物化学杂志》269卷，30939 - 30945页）。在本研究中，已对整合素与α1(IV)-531 - 543序列的肽类似物的相互作用进行了分析。针对α3整合素亚基的单克隆抗体抑制了肿瘤细胞（黑色素瘤、卵巢癌）与化学合成的α1(IV)531 - 543肽的黏附，针对β1和α2整合素亚基的单克隆抗体在较小程度上也有抑制作用。抗α5单克隆抗体和正常小鼠IgG作为肿瘤细胞与该肽黏附的抑制剂无效。两种分子量分别为120 kDa和150 kDa的细胞表面蛋白与α1(IV)531 - 543肽亲和柱结合，并用20 mM EDTA洗脱。当将洗脱的蛋白与针对α3或β1整合素亚基的单克隆抗体一起孵育时，分子量与α3和β1整合素亚基相对应的蛋白被沉淀。针对α2或α5整合素亚基的单克隆抗体未沉淀出任何蛋白。因此，已证明来自两种肿瘤细胞类型的α3β1整合素可直接与α1(IV)531 - 543肽结合。α1(IV)531 - 543肽是首个被证明能结合α3β1整合素的类胶原蛋白序列。
