A simple complex on the verge of breakdown: isolation of the elusive cyanoformate ion.
Science
; 344(6179): 75-8, 2014 Apr 04.
Article
em En
| MEDLINE
| ID: mdl-24700853
ABSTRACT
Why does cyanide not react destructively with the proximal iron center at the active site of 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase, an enzyme central to the biosynthesis of ethylene in plants? It has long been postulated that the cyanoformate anion, [NCCO2](-), forms and then decomposes to carbon dioxide and cyanide during this process. We have now isolated and crystallographically characterized this elusive anion as its tetraphenylphosphonium salt. Theoretical calculations show that cyanoformate has a very weak C-C bond and that it is thermodynamically stable only in low dielectric media. Solution stability studies have substantiated the latter result. We propose that cyanoformate shuttles the potentially toxic cyanide away from the low dielectric active site of ACC oxidase before breaking down in the higher dielectric medium of the cell.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Formiatos
/
Aminoácido Oxirredutases
/
Nitrilas
Idioma:
En
Ano de publicação:
2014
Tipo de documento:
Article