Conformational Changes of Peptides at Solid/Liquid Interfaces:  A Monte Carlo Study

• Published in: Biomacromolecules Vol. 5; no. 6; pp. 2147 - 2159
• Main Authors: Mungikar, Amol A, Forciniti, Daniel
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.11.2004
• Subjects: Adsorption; Aminoacid polymers; Applied sciences; Biophysical Phenomena; Biophysics; Exact sciences and technology; Hydrogen Bonding; Macromolecular Substances - chemistry; Models, Molecular; Models, Statistical; Models, Theoretical; Molecular Conformation; Monte Carlo Method; Oxygen - chemistry; Peptides - chemistry; Physicochemistry of polymers; Protein Conformation; Static Electricity; Synthetic biopolymers; Water - chemistry; Monte Carlo method; Liquid solid interface; Computer simulation; Liquid solid adsorption; Aminoacid copolymer; Adsorbed state; Theoretical study; Aspartic derivative copolymer; Block copolymer; Conformation
• ISSN: 1525-7797; 1526-4602
• DOI: 10.1021/bm049808s

Monte Carlo simulations were performed to study the conformational changes of negatively charged model peptides dissolved in water adsorbed onto charged surfaces. 8-, 16-, and 20-residues peptides were used, each of them consisted of repeating diblock units of aspartic acid (ASP, polar amino acid) and isoleucine (ILE, nonpolar amino acid) residues. We found that a water patch was retained at the charged surface, separating the peptide from it. We believed that these water molecules were primarily responsible for giving a particular orientation to the peptide at the surface. Water did play a role to some extent in the structural stability of the 8-residues peptide. However, for higher chain lengths (16-residues and 20-residues), the intrinsic hydrogen-bonding network (or intrinsic structural stability) showed a predominant effect over hydrophobic dehydration for the stability of the peptide at the surface.