Loading…

A Simple Complex on the Verge of Breakdown: Isolation of the Elusive Cyanoformate Ion

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...

Full description

Saved in:
Bibliographic Details
Published in:Science (American Association for the Advancement of Science) 2014-04, Vol.344 (6179), p.75-78
Main Authors: Murphy, Luke J., Robertson, Katherine N., Harroun, Scott G., Brosseau, Christa L., Werner-Zwanziger, Ulrike, Moilanen, Jani, Tuononen, Heikki M., Clyburne, Jason A. C.
Format: Article
Language:English
Subjects:
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary: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.
ISSN:0036-8075
1095-9203
DOI:10.1126/science.1250808