Kashiwagi Kenji, Shiba Kiyotaka, Fukami-Kobayashi Kaoru, Noda Tetsuo, Nishikawa Ken, Noguchi Hiroshi
School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Shizuoka 422-8526, Japan.
J Biochem. 2003 Mar;133(3):371-6. doi: 10.1093/jb/mvg049.
The family of periplasmic binding proteins (PBPs) is believed to have arisen from a common ancestor and to have differentiated into two types. At first approximation, both types of PBPs have the same fold pattern, reflecting their common origin. However, the connection between the main chains of a type 2 PBP is more complicated than a type 1 PBP's. We have been interested in the possibility that such structural changes affect the folding of PBPs. In this study, we have characterized the folding pathways of MglB (a type 1 PBP) and ArgT (a type 2 PBP) by using urea gradient gel electrophoresis, fast protein size-exclusion liquid chromatography and hydrophobic dye ANS binding assay. We found a distinct difference in folding between these two proteins. The folding of MglB followed a simple two-state transition model, whereas the folding of ArgT was more complicated.
周质结合蛋白(PBPs)家族被认为起源于一个共同的祖先,并分化为两种类型。初步估计,这两种类型的PBPs具有相同的折叠模式,反映了它们的共同起源。然而,2型PBPs主链之间的连接比1型PBPs的更复杂。我们一直对这种结构变化是否会影响PBPs的折叠感兴趣。在这项研究中,我们通过使用尿素梯度凝胶电泳、快速蛋白质尺寸排阻液相色谱和疏水染料ANS结合测定法,对MglB(一种1型PBPs)和ArgT(一种2型PBPs)的折叠途径进行了表征。我们发现这两种蛋白质在折叠方面存在明显差异。MglB的折叠遵循简单的两态转变模型,而ArgT的折叠则更为复杂。