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Title: Effects of Synthetic Amphiphilic alpha-Helical Peptides on the Electrochemical and Structural Properties of Supported Hybrid Bilayers on Gold

Abstract

Amphiphilic {alpha}-helices were formed from designed synthetic peptides comprising alanine, phenylalanine, and lysine residues. The insertion of the -helical peptides into hybrid bilayers assembled on gold was studied by a variety of methods to assess the resulting structural characteristics, such as electrical resistance and molecular orientation. Self-assembled monolayers (SAMs) of dodecanethiol (DDT); octadecanethiol (ODT); and 1,2-dipalmitoyl-sn-glycero-3-phosphothioethanol (DPPTE) were formed on gold substrates with and without incorporated peptide. Supported hybrid bilayers and multilayers of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) were formed on SAMs by the 'paint-freeze' method of bilayer formation. Modeling of electrochemical impedance spectroscopy data using equivalent electrochemical circuits revealed that the addition of peptide decreased dramatically the resistive element of the bilayer films while maintaining the value of the capacitive element, indicating successful incorporation of peptide into a well-formed bilayer. Near-edge X-ray absorption fine structure spectroscopy data provided evidence that the molecules in the SAMs and hybrid multilayers were ordered even in the presence of peptide. The peptide insertion into the SAM was confirmed by observing the {pi}* resonance peak correlating with phenylalanine and a peak in the nitrogen K-edge regime attributable to the peptide bond.

Authors:
; ; ; ;
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL) National Synchrotron Light Source
Sponsoring Org.:
Doe - Office Of Science
OSTI Identifier:
913969
Report Number(s):
BNL-78537-2007-JA
Journal ID: ISSN 0743-7463; LANGD5; TRN: US200804%%306
DOE Contract Number:
DE-AC02-98CH10886
Resource Type:
Journal Article
Resource Relation:
Journal Name: Langmuir; Journal Volume: 22; Journal Issue: 4
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; GOLD; SUBSTRATES; PEPTIDES; ELECTROCHEMISTRY; MORPHOLOGY; SYNTHETIC MATERIALS; LYSINE; PHENYLALANINE; ALANINES; national synchrotron light source

Citation Formats

Smith,M., Tong, J., Genzer, J., Fischer, D., and Kilpatrick, P.. Effects of Synthetic Amphiphilic alpha-Helical Peptides on the Electrochemical and Structural Properties of Supported Hybrid Bilayers on Gold. United States: N. p., 2006. Web. doi:10.1021/la051104w.
Smith,M., Tong, J., Genzer, J., Fischer, D., & Kilpatrick, P.. Effects of Synthetic Amphiphilic alpha-Helical Peptides on the Electrochemical and Structural Properties of Supported Hybrid Bilayers on Gold. United States. doi:10.1021/la051104w.
Smith,M., Tong, J., Genzer, J., Fischer, D., and Kilpatrick, P.. Sun . "Effects of Synthetic Amphiphilic alpha-Helical Peptides on the Electrochemical and Structural Properties of Supported Hybrid Bilayers on Gold". United States. doi:10.1021/la051104w.
@article{osti_913969,
title = {Effects of Synthetic Amphiphilic alpha-Helical Peptides on the Electrochemical and Structural Properties of Supported Hybrid Bilayers on Gold},
author = {Smith,M. and Tong, J. and Genzer, J. and Fischer, D. and Kilpatrick, P.},
abstractNote = {Amphiphilic {alpha}-helices were formed from designed synthetic peptides comprising alanine, phenylalanine, and lysine residues. The insertion of the -helical peptides into hybrid bilayers assembled on gold was studied by a variety of methods to assess the resulting structural characteristics, such as electrical resistance and molecular orientation. Self-assembled monolayers (SAMs) of dodecanethiol (DDT); octadecanethiol (ODT); and 1,2-dipalmitoyl-sn-glycero-3-phosphothioethanol (DPPTE) were formed on gold substrates with and without incorporated peptide. Supported hybrid bilayers and multilayers of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) were formed on SAMs by the 'paint-freeze' method of bilayer formation. Modeling of electrochemical impedance spectroscopy data using equivalent electrochemical circuits revealed that the addition of peptide decreased dramatically the resistive element of the bilayer films while maintaining the value of the capacitive element, indicating successful incorporation of peptide into a well-formed bilayer. Near-edge X-ray absorption fine structure spectroscopy data provided evidence that the molecules in the SAMs and hybrid multilayers were ordered even in the presence of peptide. The peptide insertion into the SAM was confirmed by observing the {pi}* resonance peak correlating with phenylalanine and a peak in the nitrogen K-edge regime attributable to the peptide bond.},
doi = {10.1021/la051104w},
journal = {Langmuir},
number = 4,
volume = 22,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 2006},
month = {Sun Jan 01 00:00:00 EST 2006}
}
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