sub-nanoscale surface ruggedness provides a water-tight seal for exposed regions in soluble protein structure得到表面强度为可溶性蛋白质暴露的地区提供了一个十全十美的密封结构.pdfVIP

Sub-Nanoscale Surface Ruggedness Provides a Water- Tight Seal for Exposed Regions in Soluble Protein Structure 1 1 1 ´ 2,3 Erica Schulz , Marisa Frechero , Gustavo Appignanesi , Ariel Fernandez * ´ ´ ´ ´ ´ 1 Seccion Fisicoquımica, Instituto de Quımica del Sur, Universidad Nacional del Sur, Consejo Nacional de Investigaciones Cientıficas y Tecnicas and Departamento de ´ ´ Quımica, Universidad Nacional del Sur, Bahıa Blanca, Argentina, 2 Department of Bioengineering, Rice University, Houston, Texas, United States of America, 3 Department of Computer Science, The University of Chicago, Chicago, Illinois, United States of America Abstract Soluble proteins must maintain backbone hydrogen bonds (BHBs) water-tight to ensure structural integrity. This protection is often achieved by burying the BHBs or wrapping them through intermolecular associations. On the other hand, water has low coordination resilience, with loss of hydrogen-bonding partnerships carrying significant thermodynamic cost. Thus, a core problem in structural biology is whether natural design actually exploits the water coordination stiffness to seal the backbone in regions that are exposed to the solvent. This work explores the molecular design features that make this type of seal operative, focusing on the side-chain arrangements that shield the protein backbone. We show that an efficient sealing is achieved by adapting the sub-nanoscale surface topography to the stringency of water coordination: an exposed BHB may be