Different Interfacial Behaviors of N- and C-Terminus Cysteine-Modified Cecropin P1 Chemically Immobilized onto Polymer Surface
MICHIGAN UNIV ANN ARBOR
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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-MApeptide 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 microM. This research shows the different interaction mechanisms between CP1c and PS-MA and between cCP1 and PS-MA.
- Genetic Engineering and Molecular Biology
- Physical Chemistry