Marinkovich M P, Lunstrum G P, Keene D R, Burgeson R E
Shriner's Hospital for Crippled Children, Portland, Oregon.
J Cell Biol. 1992 Nov;119(3):695-703. doi: 10.1083/jcb.119.3.695.
We report the identification of a novel laminin variant that appears to be unique to a subset of epithelial basement membranes. The variant contains two chains electrophoretically and immunologically identical to the B1 and B2 chains. Epitopes contained in the laminin A chain are absent from the molecule, and a 190-kD chain substitutes for the A chain. V8 protease analysis and Western blotting studies indicate that the variant 190-kD chain shows structural and immunological similarity to the 200-kD chain of kalinin. Rotary shadowing analysis indicates that the 190-kD chain contributes a large globular structure to the variant long arm, but lacks the short arm contributed to laminin by the A chain. The variant is produced by cultured skin explants, human keratinocytes and a squamous cell carcinoma line, and is present in human amniotic fluid. Polyclonal antibodies raised to kalinin, a recently characterized novel component of anchoring filaments, and mAb BM165 which recognizes a subunit of kalinin (Rousselle et al., 1991) cross react with the variant under nonreducing conditions. Immunohistological surveys of human tissues using the crossreacting antikalinin antiserum indicate that the distribution of this laminin variant is at least restricted to anchoring filament containing basement membranes. We propose the name K-laminin for this variant.
我们报告了一种新型层粘连蛋白变体的鉴定，该变体似乎是上皮基底膜亚组所特有的。该变体包含两条在电泳和免疫方面与B1和B2链相同的链。层粘连蛋白A链所含的表位在该分子中不存在，一条190-kD的链替代了A链。V8蛋白酶分析和蛋白质印迹研究表明，该变体190-kD链与角蛋白的200-kD链在结构和免疫方面具有相似性。旋转阴影分析表明，190-kD链为变体长臂贡献了一个大的球状结构，但缺乏A链为层粘连蛋白贡献的短臂。该变体由培养的皮肤外植体、人角质形成细胞和一个鳞状细胞癌系产生，并存在于人类羊水中。针对角蛋白（一种最近被鉴定的锚定丝新成分）产生的多克隆抗体，以及识别角蛋白一个亚基的单克隆抗体BM165（Rousselle等人，1991）在非还原条件下与该变体发生交叉反应。使用交叉反应的抗角蛋白抗血清对人体组织进行免疫组织学调查表明，这种层粘连蛋白变体的分布至少局限于含有锚定丝的基底膜。我们提议将这种变体命名为K-层粘连蛋白。
