HYDRATION STRUCTURE OF A COLLAGEN PEPTIDE
HYDRATION STRUCTURE OF A COLLAGEN PEPTIDE
复制标题
DOI：
10.1016/s0969-2126(01)00224-6
复制
发表时间：
1995-09-15
期刊：
影响因子：
5.7
通讯作者：
BERMAN, HM
中科院分区：
文献类型：
--
作者：
BELLA, J;BRODSKY, B;BERMAN, HM
背景：胶原蛋白三螺旋是一种独特的蛋白质基序，由聚脯氨酸 II 构象中的三个多肽链的超螺旋定义。它是所有胶原蛋白的主要结构域，据报道也存在于具有宿主防御功能的蛋白质和多种膜蛋白中。三螺旋结构域具有独特的性质。胶原蛋白需要高比例的翻译后修饰的亚氨基酸二羟脯氨酸和水来稳定其构象和组装。确定为 1.85 埃的类胶原肽的晶体结构表明这两个特征可能相关。结果：对类胶原肽的水合结构进行了详细分析。羰基和羟脯氨酰基周围的水分子显示出独特的几何形状。在单个肽链内、不同链之间以及不同三螺旋之间存在连接氧原子的水桥的重复模式。总体而言，水分子以半包合物状结构组织，围绕晶格中的三重螺旋并将其互连。羟脯氨酸基团在组装中起着至关重要的作用。结论：羟脯氨酸和水合的作用在胶原三螺旋结构中密切相关。在该结构中观察到的特定的重复水桥支撑着三螺旋构象。广泛有序的水合结构为解释胶原稳定性和组装的实验结果提供了一个很好的模型。
Background: The collagen triple helix is a unique protein motif defined by the supercoiling of three polypeptide chains in a polyproline II conformation. It is a major domain of all collagen proteins and is also reported to exist in proteins with host defense function and in several membrane proteins. The triple-helical domain has distinctive properties. Collagen requires a high proportion of the post-translationally modified imino acid di-hydroxyproline and water to stabilize its conformation and assembly. The crystal structure of a collagen-like peptide determined to 1.85 Angstrom showed that these two features may be related.Results: A detailed analysis of the hydration structure of the collagen-like peptide is presented. The water molecules around the carbonyl and hydroxyprolyl groups show distinctive geometries. There are repetitive patterns of water bridges that link oxygen atoms within a single peptide chain, between different chains and between different triple helices. Overall, the water molecules are organized in a semi-clathrate-like structure that surrounds and interconnects triple helices in the crystal lattice. Hydroxyprolyl groups play a crucial role in the assembly.Conclusions: The roles of hydroxyproline and hydration are strongly interrelated in the structure of the collagen triple helix. The specific, repetitive water bridges observed in this structure buttress the triple-helical conformation. The extensively ordered hydration structure offers a good model for the interpretation of the experimental results on collagen stability and assembly.