title: Solvent effect and time-dependent behavior of C-terminus-cysteine-modified cecropin P1 chemically immobilized on a polymer surface.
abstract: Sum frequency generation (SFG) vibrational spectroscopy has been applied to the investigation of peptide immobilization on a polymer surface as a function of time and peptide conformation. Surface immobilization of biological molecules is important in many applications such as biosensors, antimicrobial materials, biobased fuel cells, nanofabrication, and multifunctional materials. Using C-terminus-cysteine-modified cecropin P1 (CP1c) as a model, we investigated the time-dependent immobilization behavior in situ in real time. In addition, potassium phosphate buffer (PB) and mixtures of PB and trifluoroethanol were utilized to examine the effect of peptide secondary structure on CP1c immobilization to polystyrene maleimide (PS-MA). The orientation of immobilized CP1c on PS-MA was determined using polarized SFG spectra. It was found that the peptide solution concentration, solvent composition, and assembly state (monomer vs dimer) prior to immobilization all influence the orientation of CP1c on a PS-MA surface. The detailed relationship between the interfacial peptide orientation and these immobilization conditions is discussed.
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: Lauren
authors.initials: L
authors.lastname: Soblosky
authors.forename: Morris
authors.initials: M
authors.lastname: Slutsky
authors.forename: Charlene M
authors.initials: CM
authors.lastname: Mello
authors.forename: Zhan
authors.initials: Z
authors.lastname: Chen
mesh_terms: D000595:Amino Acid Sequence; D002021:Buffers; D003545:Cysteine; D055767:Immobilized Proteins / Q000737:chemistry*; D007700:Kinetics; D008301:Maleimides / Q000737:chemistry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry; D011137:Polystyrenes / Q000737:chemistry*; D017680:Potassium Compounds / Q000737:chemistry; D055503:Protein Multimerization; D020836:Protein Structure, Quaternary; D019163:Reducing Agents / Q000737:chemistry; D012996:Solutions; D012997:Solvents / Q000737:chemistry*; D013499:Surface Properties; D014270:Trifluoroethanol / Q000737:chemistry
chemical_list: D002021:Buffers; D055767:Immobilized Proteins; D008301:Maleimides; D010455:Peptides; D010710:Phosphates; D011137:Polystyrenes; D017680:Potassium Compounds; D019163:Reducing Agents; D012996:Solutions; D012997:Solvents; C043592:maleimide; D014270:Trifluoroethanol; C013216:potassium phosphate; D003545:Cysteine; C070016:cecropin P1-LI