Molecular Biophysics Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research, Bhopal 462023, India.
FEBS Lett. 2014 Nov 28;588(23):4464-71. doi: 10.1016/j.febslet.2014.10.017.
Defining the span of the transmembrane region, a key requirement to ensure correct folding, stability and function of bacterial outer membrane β-barrels, is assisted by the amphipathic property of tryptophan. We demonstrate the unique and distinctive properties of the interface Trp76 and Trp140 of outer membrane protein X, and map their positional relevance to the refolding process, barrel formation and the resulting stability in dodecylphosphocholine micelles. The solvent-exposed Trp76 displays a rigid interfacial localization, whereas Trp140 is relatively micelle-solvated and contributes to barrel folding and global OmpX stability. Kinetic contribution to OmpX stability is influenced by the two tryptophans. Differential associations of the indoles with the detergent milieu therefore contribute to micelle-assisted β-barrel folding and concomitant OmpX stability.
定义跨膜区域的范围是确保细菌外膜β-桶正确折叠、稳定和功能的关键要求，色氨酸的两亲性质有助于这一要求。我们展示了外膜蛋白 X 中色氨酸 76 位和色氨酸 140 位的独特和独特的特性，并将它们的位置相关性映射到复性过程、桶形成和 resulting stability in dodecylphosphocholine micelles 中。暴露在溶剂中的色氨酸 76 显示出刚性的界面定位，而色氨酸 140 相对地被 micelle 溶剂化，并有助于桶的折叠和整体 OmpX 的稳定性。动力学对 OmpX 稳定性的贡献受到两个色氨酸的影响。因此，吲哚与去污剂环境的不同结合有助于 micelle-assisted β-桶折叠和伴随的 OmpX 稳定性。
