School of Biological Sciences, Victoria University of Wellington, New Zealand.
Comp Biochem Physiol Part D Genomics Proteomics. 2012 Mar;7(1):28-34. doi: 10.1016/j.cbd.2011.10.004. Epub 2011 Oct 29.
The glutathione transferases (GSTs) are a large group of enzymes having both detoxication roles and specialist metabolic functions. The present work represents an initial approach to identifying some of these roles by examining the variation of specific members of the family under differing conditions. The GSTs from Lucilia cuprina have been partially purified, members of two families being isolated, by the use of glutathione immobilised on epichlorhydrin-activated Sepharose 6B. The GSTs were separated by 2D SDS-PAGE and characterised by MALDI-TOF analysis of tryptic peptides. The mass fragments were then matched against the corresponding Drosophila melanogaster and Musca domestica sequences. GSTs were identified as coming from only the Sigma and Delta classes. The multiple Delta zones appear all to be derived from the Lucilia GSTD1 isoform. The distribution of these GST proteins has been studied during different developmental stages of the insect. Delta isoforms were present in all developmental stages of L. cuprina. The Sigma GST was not detectable in the egg, was just detectable in the larval and pupal stages and was the major GST isolated in the adult. Sigma and Delta isoforms were both found in all body segments of the insect. Both isoforms appear to undergo extensive post-translational modification. Activities of the two types of protein with model substrates have been determined.
谷胱甘肽转移酶（GSTs）是一大类具有解毒作用和特殊代谢功能的酶。本工作通过研究不同条件下家族中特定成员的变化，初步探讨了其中的一些作用。采用谷胱甘肽固定在表氯醇活化的 Sepharose 6B 上的方法，对丽蝇蛹集金小蜂 GSTs 进行了部分纯化，分离出两个家族的成员。通过二维 SDS-PAGE 分离 GSTs，并通过胰蛋白酶肽的 MALDI-TOF 分析进行特性分析。然后将质量片段与相应的黑腹果蝇和家蝇序列进行匹配。鉴定 GST 仅来自 Sigma 和 Delta 类。多个 Delta 区似乎都来自丽蝇 GSTD1 同工型。研究了 GST 蛋白在昆虫不同发育阶段的分布。Delta 同工型存在于丽蝇蛹集金小蜂的所有发育阶段。Sigma GST 在卵中不可检测，在幼虫和蛹期仅可检测到，在成虫中是主要分离的 GST。Sigma 和 Delta 同工型均存在于昆虫的所有体节中。两种同工型似乎都经历了广泛的翻译后修饰。已经确定了两种类型的蛋白质与模型底物的活性。
