title: Different interfacial behaviors of N- and C-terminus cysteine-modified cecropin P1 chemically immobilized onto polymer surface.
abstract: Sum frequency generation (SFG) vibrational spectroscopy and attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) were used to investigate the orientation of N-terminus cysteine-modified cecropin P1 (cCP1) at the polystyrene maleimide (PS-MA)/peptide phosphate buffer solution interface. The cCP1 cysteine group reacts with the maleimide group on the PS-MA surface to chemically immobilize cCP1. Previously, we found that the C-terminus cysteine-modified cecropin P1 (CP1c) molecules exhibit a multiple-orientation distribution at the PS-MA/peptide phosphate buffer solution interface, due to simultaneous physical adsorption and chemical immobilization of CP1c on the PS-MA surface. Differently, in this research, it was found that the interfacial orientation of cCP1 molecules varied from a horizontal orientation to the "tilting" orientation to the "standing up" orientation and then to the "multiple-orientation" distribution as the peptide concentration increased from 0.19 to 3.74 μM. This research shows the different interaction mechanisms between CP1c and PS-MA and between cCP1 and PS-MA.
authors.affiliation: Department of Chemistry, University of Michigan , Ann Arbor, Michigan 48109, United States.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Han
authors.forename: Joshua R
authors.initials: JR
authors.lastname: Uzarski
authors.forename: Charlene M
authors.initials: CM
authors.lastname: Mello
authors.forename: Zhan
authors.initials: Z
authors.lastname: Chen
mesh_terms: D003545:Cysteine / Q000737:chemistry*; D055767:Immobilized Proteins / Q000737:chemistry*; D015394:Molecular Structure; D010455:Peptides / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties
chemical_list: D055767:Immobilized Proteins; D010455:Peptides; D011108:Polymers; D003545:Cysteine; C070016:cecropin P1-LI