Requirements for Cell-Free Cyanide Oxidation by Pseudomonas Fluorescens NCIMB 11764

The involvement of cyanide oxygenase in the metabolism of pyruvate and a-ketoglutarate-cyanohydrin was investigated and shown to occur indirectly by the consumption of free cyanide arising from the cyanohydrins via chemical dissociation. Thus, free cyanide remains the substrate, for which the enzyme displays a remarkably high affinity (Kmapp,4 mM). A model for cyanide utilization is therefore envisioned in which the substrate is initially detoxified by complexation to an appropriate ligand followed by enzymatic oxidation of cyanide arising at sublethal levels via chemical dissociation. Putative cyanide oxygenase in cell extracts consumed both oxygen and NADH in equimolar proportions during cyanide conversion to CO2 and NH3 and existed separately from an unknown heat-stable species responsible for the nonenzymatic cyanide-catalyzed consumption of oxygen. Evidence of cyanide inhibition and nonlinear kinetics between enzyme activity and protein concentration point to a complex mechanism of enzymatic substrate conversion.

Grantor dc:publisher

University of North Texas

Year dc:date

2000

Author dc:creator

• Parab, Preeti

Contributors dc:contributor

• Kunz, Daniel A.
• Pirtle, Robert M.
• Farinha, Mark A.

• Pseudomonas fluorescens.
• Cyanides -- Metabolism.
• NADH
• enzyme
• cyanide
• nonlinear kinetics
• pyruvate

Statement dc:rights

• Public
• Copyright
• Parab, Preeti
• Copyright is held by the author, unless otherwise noted. All rights reserved.

Language dc:language

English

Identifier

oclc: 49937854
untcat: b2374892
https://digital.library.unt.edu/ark:/67531/metadc2614/
ark: ark:/67531/metadc2614

OAI identifier oai:identifier

info:ark/67531/metadc2614