Kramer R Z, Bella J, Brodsky B, Berman H M
Department of Chemistry, Rutgers University, 610 Taylor Rd., Piscataway, NJ, 08854-8087, USA.
J Mol Biol. 2001 Aug 3;311(1):131-47. doi: 10.1006/jmbi.2001.4849.
A detailed description of the 2.0 A structure of the triple-helical peptide, (Pro-Hyp-Gly)(3)-Ile-Thr-Gly-Ala-Arg-Gly-Leu-Ala-Gly-Pro-Hyp-Gly-(Pro-Hyp-Gly)(3), denoted as T3-785, is presented. This peptide contains a biologically relevant sequence and was designed to model the imino acid-poor 785-796 region of human type III collagen just C-terminal to the matrix metalloproteinase cleavage site. The crystal structure of the T3-785 peptide demonstrates that sequence can influence local conformational changes in triple-helical structure, in terms of superhelical pitch, hydrogen bonding pattern, and hydration patterns. The novel packing arrangement displayed by the T3-785 structure, compared with those of collagen-like peptides with more imino acid-rich sequences indicates the sequence dependence of intermolecular assemblies in collagen as well. The observed synergy between the packing arrangements and the extended hydration network indicates that hydration of the triple helix is directly related to its association with other molecules.
本文详细描述了三螺旋肽(Pro-Hyp-Gly)(3)-Ile-Thr-Gly-Ala-Arg-Gly-Leu-Ala-Gly-Pro-Hyp-Gly-(Pro-Hyp-Gly)(3)的2.0 Å结构，该肽被命名为T3-785。此肽包含一个具有生物学相关性的序列，其设计目的是模拟人类III型胶原蛋白中紧邻基质金属蛋白酶切割位点C端的贫亚氨基酸785-796区域。T3-785肽的晶体结构表明，就超螺旋螺距、氢键模式和水合模式而言，序列可影响三螺旋结构中的局部构象变化。与具有更多富亚氨基酸序列的类胶原蛋白肽相比，T3-785结构所展示的新型堆积排列也表明了胶原蛋白中分子间组装的序列依赖性。堆积排列与扩展水合网络之间观察到的协同作用表明，三螺旋的水合作用与其与其他分子的缔合直接相关。
