The carboxylate shift in zinc enzymes: A computational study

• Tipo: Artigo em Revista Científica Internacional
• Data: 2007

Autores

Sergio F Sousa (Autor) Outra; Pedro A Fernandes (Autor) FCUP; Maria Joao Ramos (Autor) FCUP

Revista

Título: Journal of the American Chemical Society

Vol. 129 Nº 50

Páginas: 1378-1385

ISSN: 0002-7863

Editora: American Chemical Society

Indexação

ISI Web of Knowledge - 122 Citações

Scopus - 125 Citações

Classificação Científica

FOS: Ciências exactas e naturais > Química

Outras Informações

ID Authenticus: P-004-BV5

DOI: 10.1021/ja067103n

Abstract (EN): Zinc is the second most abundant transition element in biology and the only metal known to be represented in enzymes from each one of the six classes established by the International Union of Biochemistry. The flexible coordination geometry, the fast ligand exchange, the lack of redox activity, and its role as Lewis acid are just some of the features that make zinc an invaluable element in biological catalysis. In this study, we have analyzed the importance in mononuclear Zn enzymes of an interesting mechanistic phenomenon known as carboxylate shift, which is characterized by a change in the coordination mode of a carboxylate group (mono to bidentate or vice versa) with both ligand entrance or exit from the metal coordination sphere. Using B3LYP calculations, we were able to unveil in detail patterns relating the intrinsic characteristics of a given Zn coordination sphere with the existence or not of a carboxylate-shift mechanism and the additional energy stabilization arising from it. In particular, a specific Zn coordination sphere containing a carboxylate ligand (Asp or Glu), a cysteine, and a histidine has been shown to have the most favorable combination of amino acid residues that ensures a fast ligand exchange.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 8