A molecular dynamics study of the stoichiometric complex formed by poly (alpha, L-glutamate) and octyltrimethylammonium ions in chloroform solution.
We present a molecular dynamics simulation at 300 K in explicit solvent environment of chloroform of the stoichiometric complex formed by poly(alpha,L-glutamate) and octyltrimethylammonium ions. We observed that the alpha-helix conformation of the polypeptide chain remains stable during a 2-ns run. The surfactant ions predominantly adopted an extended conformation that is stabilized by favorable interactions with the organic solvent. Analysis of the organization of the surfactant with respect to the polypeptide chain indicated that each octyltrimethylammonium cation was preferentially bound to more than one carboxylate group. It was found that the most populated arrangement was that with the surfactant cations interacting with two carboxylate groups simultaneously.
Zanuy
David
D
Department d'Enginyeria Química, E. T. S. d'Enginyers Industrials de Barcelona, Universitat Politècnica de Catalunya, Diagonal 647, Barcelona E-08028, Spain.
Alemán
Carlos
C
Muñoz-Guerra
Sebastián
S
D002412:Cations; D002725:Chloroform / Q000737:chemistry*; D002942:Circular Dichroism; D003198:Computer Simulation; D006860:Hydrogen Bonding; D046911:Macromolecular Substances; D008958:Models, Molecular; D011099:Polyglutamic Acid / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D000644:Quaternary Ammonium Compounds / Q000737:chemistry* / Q000378:metabolism; D012996:Solutions; D012997:Solvents / Q000737:chemistry*; D055672:Static Electricity; D013501:Surface-Active Agents / Q000737:chemistry* / Q000378:metabolism; D013816:Thermodynamics
D002412:Cations; D046911:Macromolecular Substances; D000644:Quaternary Ammonium Compounds; D012996:Solutions; D012997:Solvents; D013501:Surface-Active Agents; C042006:octyltrimethylammonium; D011099:Polyglutamic Acid; D002725:Chloroform