Hebert Hans, Jegerschöld Caroline
Karolinska Institutet, Department of Biosciences and Nutrition and Royal Institute of Technology, School of Technology and Health, Novum, S-141 57 Huddinge, Sweden.
Curr Opin Struct Biol. 2007 Aug;17(4):396-404. doi: 10.1016/j.sbi.2007.07.008. Epub 2007 Sep 17.
Membrane associated proteins in eicosanoid and glutathione metabolism (MAPEG) are involved in biosynthesis of arachidonic-derived mediators of pain, fever, and inflammation as well as in biotransformation and detoxification of electrophilic substances. Structure determination of microsomal glutathione transferase 1 using electron crystallography has provided the first atomic model of an MAPEG member. The homotrimer consists of three repeats of a four-helix transmembrane bundle with the largest extramembranous domain connecting the first and second helix and with a short proline rich loop on the same side between helices three and four. Residues of importance for intramolecular or intermolecular contacts as well as for stabilizing the active site have been identified and the results can be applied for interpreting structure-function relationship for similar MAPEG members.
类花生酸与谷胱甘肽代谢中的膜相关蛋白（MAPEG）参与花生四烯酸衍生的疼痛、发热和炎症介质的生物合成，以及亲电物质的生物转化和解毒。利用电子晶体学对微粒体谷胱甘肽转移酶1进行结构测定，得到了MAPEG成员的首个原子模型。同三聚体由四个螺旋跨膜束的三个重复单元组成，最大的膜外结构域连接第一和第二螺旋，在第三和第四螺旋之间的同一侧有一个富含脯氨酸的短环。已确定对分子内或分子间接触以及稳定活性位点重要的残基，其结果可用于解释类似MAPEG成员的结构-功能关系。
