Littauer U Z, Giveon D, Thierauf M, Ginzburg I, Ponstingl H
Proc Natl Acad Sci U S A. 1986 Oct;83(19):7162-6. doi: 10.1073/pnas.83.19.7162.
A specific binding assay was developed that monitors the interaction of 125I-labeled microtubule-associated proteins (MAPs) with tubulin or its fragments bound to nitrocellulose membrane. To identify the tubulin-binding domains for MAPs we have examined the binding of rat brain 125I-labeled MAP2 or 125I-labeled tau factors to 60 peptides derived from porcine alpha- and beta-tubulin. MAP2 and tau factors specifically interacted with two peptides derived from the carboxyl-terminal region of beta-tubulin, which are located between positions 392-445 and 416-445. In addition, there is a distinct tau-binding site at the amino-terminal region of alpha-tubulin. tau factors but not MAP2 displayed strong interaction with a peptide derived from the amino-terminal domain of alpha-tubulin between positions 1 and 75. To narrow down the location of the beta-tubulin binding site that is common to MAP2 and tau factors, we have synthesized five peptides that are homologous to the corresponding sequence from the porcine or rat carboxyl-terminal region. Binding studies with the synthetic peptides suggest that amino acid residues 434-440 of beta-tubulin are crucial for the interaction of MAP2 and tau factors.
开发了一种特异性结合测定法，用于监测125I标记的微管相关蛋白（MAPs）与结合在硝酸纤维素膜上的微管蛋白或其片段之间的相互作用。为了鉴定MAPs的微管蛋白结合结构域，我们检测了大鼠脑125I标记的MAP2或125I标记的tau因子与来自猪α-和β-微管蛋白的60种肽段的结合情况。MAP2和tau因子与来自β-微管蛋白羧基末端区域的两个肽段特异性相互作用，这两个肽段位于392 - 445位和416 - 445位之间。此外，在α-微管蛋白的氨基末端区域存在一个独特的tau结合位点。tau因子而非MAP2与来自α-微管蛋白氨基末端结构域1至75位之间的一个肽段表现出强烈的相互作用。为了缩小MAP2和tau因子共有的β-微管蛋白结合位点的位置，我们合成了五种与猪或大鼠羧基末端区域相应序列同源的肽段。对合成肽段的结合研究表明，β-微管蛋白的434 - 440位氨基酸残基对于MAP2和tau因子的相互作用至关重要。
