Thermal stability of the secondary structure of poly(alpha,L-glutamate) in self-assembled complexes as studied by molecular dynamics in chloroform solution.
The thermal stability of the self-assembled complexes formed by alkyltrimethylammonium surfactants and poly(alpha,l-glutamate) is investigated in dilute chloroform solution by molecular dynamics simulations. By applying temperatures ranging from 300 to 500 K, we observed an extraordinary stability of the alpha-helix adopted by the polypeptide during a total of 48 ns. The multiple electrostatic interactions formed between the surfactant chains and the polyanion play a crucial role in this stability since they are responsible for the inaccessibility of the solvent molecules to the helix even at high temperatures.
Zanuy
David
D
Laboratory of Experimental and Computational Biology, NCI-Frederick, Building 469, Room 151, Frederick, Maryland 21702, USA. zanuyd@ncifcrf.gov
Casanovas
Jordi
J
Alemán
Carlos
C
D002725:Chloroform; D006358:Hot Temperature; D011099:Polyglutamic Acid / Q000737:chemistry*; D017433:Protein Structure, Secondary; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D012996:Solutions; D013501:Surface-Active Agents / Q000737:chemistry; D013816:Thermodynamics
D000644:Quaternary Ammonium Compounds; D012996:Solutions; D013501:Surface-Active Agents; D011099:Polyglutamic Acid; D002725:Chloroform