Theoretical study of arginine-carboxylate interactions

• Tipo: Artigo em Revista Científica Internacional
• Data: 1999

Autores

Melo, A (Autor) FCUP; Ramos, MJ (Autor) FCUP; Floriano, WB (Autor) Outra; Gomes, JANF (Autor) FCUP; Leao, JFR (Autor) Outra; Magalhaes, AL (Autor) FCUP; Maigret, B (Autor) Outra; Nascimento, MC (Autor) Outra; Reuter, N (Autor) Outra

Revista

Título: Journal of Molecular Structure: THEOCHEM

Vol. 463

Páginas: 81-90

ISSN: 0166-1280

Editora: Elsevier B.V.

Indexação

ISI Web of Knowledge - 36 Citações

Scopus - 39 Citações

Classificação Científica

FOS: Ciências exactas e naturais > Química

Outras Informações

ID Authenticus: P-001-4JT

DOI: 10.1016/s0166-1280(98)00396-0

Abstract (EN): The importance of the guanidinium-carboxylate interactions has sprung from the observed salt bridges often present in biological systems involving the arginine-glutamate or arginine-aspartate side chains. The strength of these interactions has been explained on the basis of a great coulombic energy gain, due to the closeness of two charges of opposite sign and the occurrence of H-bond interactions. However, in some environments proton transfer, from guanidinium to carboxylate, can occur with the consequent annihilation of charge. In this work, both ab-initio (6-31G** and MP2/6-31G**) and semi-empirical (AM1) calculations were performed in vacuo on appropriate models, methylguanidinium-acetate and methylguanidine-acetic acid to simulate the zwitterionic and the neutral forms, respectively. The results obtained indicate that, in solvent-free hydrophobic environments, the neutral form should be more stable than the zwitterionic one.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 10