摘要：  Molecular recognition of proteins harnesses various intermolecular interactions, where ionic interactions play an essential role. Regarding that only a limited number of polar residues are available to proteins, it is intriguing to think how a diversity of their recognition events is developed in nature. In our study, we found that ionic interactions on a hydrophobic surface are modulated by their subnanoscale distance to the surface: This subnanoscale modulation enables a precise modulation of molecular binding affinity over a wide range. Inspired by GPCRs in nature, we developed a series of ionic groups-appended voltage-responsive self-assembled monolayers (SAMs) with C2, C6, C8, and C12 space-filling alkyl chains, which capture a dendritic guest via the formation of multiple salt bridges. The guest release upon protonolysis is progressively suppressed when its distance from the background hydrophobe changes from 1.2 (C2) to 0.2 (C12) nanometers, with an increase in salt bridge strength of ~3.9 kilocalories per mole. Our results provide a first experimental proof for a physical theory postulated in the 1950s and sheds lights on how nature harnesses a limited number of polar residues to create diverse molecular recognition patterns. This understanding paves the way for the design of next-generation smart interfaces for applications in materials and pharmaceuticals.

 

报告人简介：清华大学化学工程系化工与工业生物工程本科（2005）、生物化工硕士（2008）、东京工业大学生物工程硕士（2008）、东京大学化学生物学博士（2011），现任日本理化学研究所脑科学研究中心研究员

 

代表论文：

Chen S, Itoh Y, Masuda T, Shimizu S, Zhao J, Ma J, Nakamura S, Okuro K, Noguchi H, Uosaki K, Aida T (2015) Subnanoscale hydrophobic modulation of salt bridges in aqueous media. Science. 348:555–559.

Chen S, Huang ZL, Wu JJ, Chen Y, Ye FC, Zhang C, Yatsunami R, Nakamura S, Xing XH (2013) Combination of site-directed mutagenesis and calcium ion addition for enhanced production of thermostable MBP-fused heparinase I in recombinant Escherichia coli. Appl Microbiol Biotechnol. 97:2907–2916.

Chen S, Ye FC, Chen Y, Chen Y, Zhao HX, Nakamura S, Arisaka F, Xing XH (2011) Biochemical analysis and kinetic modeling of the thermal inactivation of MBP-fused heparinase I: implications for a comprehensive thermostabiliztion strategy, Biotechnol Bioeng. 108:1841–1851.