CELL-ADHESION, SPREADING AND NEURITE STIMULATION BY LAMININ FRAGMENT-E8 DEPENDS ON MAINTENANCE OF SECONDARY AND TERTIARY STRUCTURE IN ITS ROD AND GLOBULAR DOMAIN
CELL-ADHESION, SPREADING AND NEURITE STIMULATION BY LAMININ FRAGMENT-E8 DEPENDS ON MAINTENANCE OF SECONDARY AND TERTIARY STRUCTURE IN ITS ROD AND GLOBULAR DOMAIN
复制标题
DOI：
10.1111/j.1432-1033.1990.tb19151.x
复制
发表时间：
1990-07-31
期刊：
影响因子：
--
通讯作者：
EDGAR, D
中科院分区：
文献类型：
--
作者：
DEUTZMANN, R;AUMAILLEY, M;EDGAR, D
通过蛋白水解降解、变性、合成肽和抗体抑制来探测小鼠肿瘤层粘连蛋白片段E8的细胞粘附、铺展和促进神经突的性质，所述片段E8含有负责层粘连蛋白-细胞相互作用的主要位点。去除一半以上的N-末端部分，有助于棒状结构域没有影响细胞附着或扩散，虽然神经突促进活性降低。更广泛的杆或球状域的E8的降解，或从杆的小球的分离，也导致细胞铺展活性的损失，虽然弱附着被发现到一个A链亚片段，包括球状域和一个短的杆。E8暴露于浓度增加的解离剂产生了明显可逆的变性，但不可逆的损失的附件和神经突促进活动，还原和烷基化的二硫键在球状域。虽然细胞粘附和扩散被α 6整联蛋白亚基的抗体阻断，但神经突生长不受影响，表明这两种活性有两种不同的受体。此外，发现一种合成肽是无活性的，该合成肽的序列发现于粘附和神经突促进位点附近，并且先前与神经突生长和细胞附着活性有关。这些结果表明，层粘连蛋白的主要细胞附着和神经突促进位点是不同的，虽然都需要的杆和层粘连蛋白的长臂的末端球状域的部分的天然构象。
The cell adhesion, spreading and neurite-promoting properties of mouse tumor laminin fragment E8, which contains major sites(s) responsible for laminin - cell interactions, were probed by proteolytic degradation, denaturation, synthetic peptides and antibody inhibition. Removal of more than half of the N-terminal portion contributing to the rod-like domain did not effect cell attachment or spreading although neurite-promoting activity was reduced. More extensive degradation of the rod or of the globular domains of E8, or separation of the globule from the rod, also resulted in loss of cell spreading activity although weak attachment was found to an A chain subfragment comprising the globular domain and a short piece of the rod. Exposure of E8 to increasing concentrations of dissociating agents produced an apparently reversible denaturation but an irreversible loss of both attachment and neurite-promoting activities, as did reduction and alkylation of disulfide bonds in the globular domain. Although cell adhesion and spreading were blocked by antibodies to an .alpha.6 integrin subunit, neurite outgrowth was unaffected, indicating two distinct receptors for these two activities. Furthermore, a synthetic peptide, the sequence of which is found in the vicinity of adhesion and neurite-promoting sites and previously implicated in neurite growth and cell attachment activities, was found to be inactive. These results indicate that the major cell attachment and neurite-promoting sites of laminin are distinct although both require the native conformation of parts of the rod and the terminal globular domain of the long arm of laminin.