Yu Zhuoxin, An Bo, Ramshaw John A M, Brodsky Barbara
Department of Biochemistry, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA.
Department of Biomedical Engineering, Tufts University, Medford, MA 02155, USA.
J Struct Biol. 2014 Jun;186(3):451-61. doi: 10.1016/j.jsb.2014.01.003. Epub 2014 Jan 14.
A large number of collagen-like proteins have been identified in bacteria during the past 10years, principally from analysis of genome databases. These bacterial collagens share the distinctive Gly-Xaa-Yaa repeating amino acid sequence of animal collagens which underlies their unique triple-helical structure. A number of the bacterial collagens have been expressed in Escherichia coli, and they all adopt a triple-helix conformation. Unlike animal collagens, these bacterial proteins do not contain the post-translationally modified amino acid, hydroxyproline, which is known to stabilize the triple-helix structure and may promote self-assembly. Despite the absence of collagen hydroxylation, the triple-helix structures of the bacterial collagens studied exhibit a high thermal stability of 35-39°C, close to that seen for mammalian collagens. These bacterial collagens are readily produced in large quantities by recombinant methods, either in the original amino acid sequence or in genetically manipulated sequences. This new family of recombinant, easy to modify collagens could provide a novel system for investigating structural and functional motifs in animal collagens and could also form the basis of new biomedical materials with designed structural properties and functions.
在过去十年中，人们在细菌中鉴定出了大量类胶原蛋白，主要是通过对基因组数据库的分析。这些细菌胶原蛋白具有动物胶原蛋白独特的甘氨酸-任意氨基酸-任意氨基酸重复氨基酸序列，这是其独特三螺旋结构的基础。一些细菌胶原蛋白已在大肠杆菌中表达，并且它们都呈现出三螺旋构象。与动物胶原蛋白不同，这些细菌蛋白不包含翻译后修饰的氨基酸羟脯氨酸，已知羟脯氨酸可稳定三螺旋结构并可能促进自组装。尽管缺乏胶原蛋白羟基化，但所研究的细菌胶原蛋白的三螺旋结构仍表现出35-39°C的高热稳定性，接近哺乳动物胶原蛋白的热稳定性。这些细菌胶原蛋白很容易通过重组方法大量生产，无论是原始氨基酸序列还是经过基因操作的序列。这个新的重组且易于修饰的胶原蛋白家族可以为研究动物胶原蛋白的结构和功能基序提供一个新系统，也可以成为具有设计结构特性和功能的新型生物医学材料的基础。
