Interaction of the bHLH-zip domain of c-Myc with H1-type peptides. Characterization of helicity in the H1 peptides by NMR.
Interaction of the bHLH-zip domain of c-Myc with H1-type peptides. Characterization of helicity in the H1 peptides by NMR.
复制标题
c-Myc 的 bHLH-zip 结构域与 H1 型肽的相互作用。
DOI：
10.1016/s0021-9258(17)42096-5
复制
发表时间：
1994
期刊：
影响因子：
--
通讯作者：
G. P. Mullen
中科院分区：
文献类型：
--
作者：
L. Draeger;G. P. Mullen
c-Myc-92 的羧基末端 92 个残基显示出对共有序列 5'-CACCACGTGGTG-3' 的位点特异性 DNA 结合特异性（Blackwell, T. K.、Kretzner, L.、Blackwood, E. M.、Eisenman, R. N. 和 Weintraub, H. (1990) Science 250, 1149-1151）。对纯化的融合蛋白谷胱甘肽 S-转移酶-c-Myc-92 进行尺寸排阻高压液相色谱分析表明，c-Myc-92 是四聚体，解离常数 < 60 nM。来自 c-Myc 和 Max 的碱性螺旋环螺旋拉链结构域的 Helix-1 (H1) 和亮氨酸拉链肽被测定为 c-Myc-92 DNA 结合的潜在抑制剂。具有赋予更大螺旋性的取代的 H1 肽被发现可以抑制 c-Myc-92 DNA 结合。抑制机制涉及 H1 肽与四聚体 c-Myc-92 的协同结合，通过使用 2,4-二硝基苯基-H1-F8A 的分光光度测定法测定。 NMR 结构表征揭示了螺旋度和抑制之间的相关性。在部分疏水环境中，H1-Mx（来自Max）是无规卷曲，而H1-WT、H1-F8A和H1-F8A、S6A（来自c-Myc）显示出不同程度的螺旋性。基于核奥弗豪瑟效应数据的结构测定表明，H1-F8A 螺旋比 H1-WT 明显更加有序。基于 Max X 射线结构的分析（Ferré-D'Amaré, R.、Prendergast, G. C.、Ziff, E. B. 和 Burley, S. K. (1993) Nature 363, 38-45）表明，H1 肽与 c-Myc-92 的结合可能是通过改变 c-Myc-92 中 helix-1 的堆积或通过与暴露的疏水性残基簇相互作用而发生的。在每个 H1-H2 接口处。 H1 肽的这个结合位点可能在 c-Myc 与参与转录调节的蛋白质的相互作用中具有重要意义。
The carboxyl-terminal 92 residues of c-Myc-92 display site-specific DNA binding specificity for the consensus sequence 5‘-CACCACGTGGTG-3‘ (Blackwell, T. K., Kretzner, L., Blackwood, E. M., Eisenman, R. N., and Weintraub, H. (1990) Science 250, 1149-1151). Size exclusion high pressure liquid chromatography analysis of the purified fusion protein, glutathione S-transferase-c-Myc-92, indicates that c-Myc-92 is tetrameric with a dissociation constant of < 60 nM. Helix-1 (H1) and leucine zipper peptides from the basic-helix-loop-helix-zipper domain of c-Myc and Max were assayed as potential inhibitors of c-Myc-92 DNA binding. H1 peptides with substitutions that confer greater helicity are found to inhibit c-Myc-92 DNA binding. The mechanism of inhibition involves the cooperative binding of H1 peptides with tetrameric c-Myc-92 as determined by a spectrophotometric assay employing 2,4-dinitrophenyl-H1-F8A. NMR structural characterization reveals a correlation between helicity and inhibition. In a partially hydrophobic environment, H1-Mx (from Max) is a random coil, while H1-WT, H1-F8A, and H1-F8A,S6A (from c-Myc) display differing degrees of helicity. Structure determination on the basis of nuclear Overhauser effect data indicates that the H1-F8A helix is significantly more ordered than H1-WT. Analysis on the basis of the Max x-ray structure (Ferré-D'Amaré, R., Prendergast, G. C., Ziff, E. B., and Burley, S. K. (1993) Nature 363, 38-45) suggests that H1 peptide binding to c-Myc-92 may occur through an alteration in the packing of helix-1 in c-Myc-92 or through an interaction with an exposed hydrophobic cluster of residues at each H1-H2 interface. This binding site for H1 peptides may be of significance in the interaction of c-Myc with proteins involved in transcriptional regulation.