Basement membrane macromolecules: Insights from atomic force microscopy
Basement membrane macromolecules: Insights from atomic force microscopy
复制标题
DOI：
10.1006/jsbi.2000.4252
复制
发表时间：
2000-07-01
影响因子：
3
通讯作者：
Hansma, HG
中科院分区：
文献类型：
--
作者：
Chen, CH;Hansma, HG
用原子力显微镜(AFM)对基底膜的主要大分子--IV型胶原层粘连蛋白-1和硫酸乙酰肝素蛋白多糖(HSPG)--进行了单独和联合分析。定位了层粘连蛋白与胶原蛋白TV结合的位置，并与IV型胶原氨基酸序列中缺失的位置进行了比较；测量了HSPG蛋白多糖的表观分子体积，并用其估计了相应的分子量。即使是细丝状的聚阴离子硫酸乙酰肝素链，也可以用原子力显微镜观察到，而不需要染色、涂层或固定。这些链是单链多糖链，因此比单链DNA薄。HSPG中的硫酸乙酰肝素链是肾脏基底膜蛋白过滤所必需的。我们认为，这些细链通过起到熵刷子的作用来过滤蛋白质--即，它们通过基底膜上持续的热驱动运动来过滤蛋白质。这些空气中的AFM分析是在基膜大分子相互作用的流体中进行AFM分析的一步。(C)2000年学术出版社。
The major macromolecules of basement membranes-collagen IV laminin-1, and heparan sulfate proteoglycan (HSPG)-have been analyzed by atomic force microscopy (AFM), both individually and in combination with each other. The positions of laminin binding to collagen TV were mapped and compared with the positions of imperfections in the amino acid sequence of collagen IV; the apparent molecular volumes of the HSPG proteoglycans were measured and used to estimate the corresponding molecular weights. Even the thin, thread-like strands of the polyanion heparan sulfate can be visualized with AFM without staining, coating, or fixation. These strands are single polysaccharide chains and are thus thinner than single-stranded DNA. The heparan sulfate strands in HSPG are necessary for protein filtration in kidney basement membranes. We propose that these thin strands filter proteins by functioning as an entropic brush-i.e., that they filter proteins by their constant thermally driven motion in the basement membrane. These AFM analyses in air are a step toward AFM analyses under fluid of basement membrane macromolecules interacting with each other. (C) 2000 Academic Press.