title: Orientation of a Y-shaped biomolecule adsorbed on a charged surface.
abstract: The adsorption and orientation properties of a Y-shaped biomolecule, which models an immunoglobulin (Ig), on a charged surface are analyzed mesoscopically by Monte Carlo simulations. The orientation is a consequence of the interplay between van der Waals interactions and electrostatic interactions. For adsorption dominated by van der Waals attraction, the molecule prefers lying flat on the surface. For weak attraction, we observe a depletion zone in the concentration profile, which can result in a negative surface excess. A secondary peak is found for strong adsorption. For electrostatically dominated adsorption, the orientation is mainly determined by electric dipole and a vertically adsorbed molecule can be attained as it possesses strong electric dipole. Our study provides an explanation for experimental observations of preferential orientation.
authors.affiliation: Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan 106, Republic of China.
authors.forename: Yu-Jane
authors.initials: YJ
authors.lastname: Sheng
authors.forename: Heng-Kwong
authors.initials: HK
authors.lastname: Tsao
authors.forename: Jian
authors.initials: J
authors.lastname: Zhou
authors.forename: Shaoyi
authors.initials: S
authors.lastname: Jiang
mesh_terms: D000327:Adsorption; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D007136:Immunoglobulins / Q000737:chemistry*; D066298:In Vitro Techniques; D015394:Molecular Structure; D009010:Monte Carlo Method; D011487:Protein Conformation; D055672:Static Electricity; D013499:Surface Properties
chemical_list: D007136:Immunoglobulins