title: Quinary Interactions Weaken the Electric Field Generated by Protein Side-Chain Charges in the Cell-like Environment.
abstract: The intramolecular electric field (e-field) generated by protein GB3 side-chain charges K/E10, K/E19, and D/K40 was measured in the absence or presence of macromolecular crowding. The e-field responds differently to different crowding agents-dextran, Ficoll, BSA, and E. coli cell lysate. Dextran and Ficoll have no effect on the e-field. The lysate generally weakens the e-field but the amplitude of weakening varies greatly. For example, the e-field by K19 is reduced by 67% in the presence of 90 g/L lysate, corresponding to a charge change from 0.9 to 0.3 e for K19, whereas the e-fields by D/K40 are weakened only by ∼7% under the same lysate concentration. The extent of the e-field weakening by BSA is in between that by Ficoll (dextran) and lysate. Further investigations suggest that the e-field weakening mechanism by lysate is similar to that by NaCl. That is, the e-field generated by a protein surface charge affects the distribution of lysate which creates a reaction field and weakens the protein e-field. Our study indicates that the protein electrostatic property can be changed significantly due to quinary interaction with the cell environment.
authors.affiliation: University of Chinese Academy of Sciences , Beijing 100049, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Zhang
authors.forename: Liaoyuan
authors.initials: L
authors.lastname: An
authors.affiliation: University of Chinese Academy of Sciences , Beijing 100049, China.
authors.forename: Jingwen
authors.initials: J
authors.lastname: Li
authors.affiliation: National Center for Protein Science Shanghai, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences , Shanghai 201210, China.
authors.forename: Zhijun
authors.initials: Z
authors.lastname: Liu
authors.forename: Lishan
authors.identifier: 0000-0003-1797-922X
authors.initials: L
authors.lastname: Yao
mesh_terms: D004926:Escherichia coli / Q000737:chemistry*; D008954:Models, Biological; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D055672:Static Electricity
chemical_list: D012710:Serum Albumin, Bovine