Bacterial Cyanide Assimilation: Pterin Cofactor and Enzymatic Requirements for Substrate Oxidation

PDF Version Also Available for Download.

Description

Utilization of cyanide as the sole nitrogen source by Pseudomonas fluorescens NCIMB 11764 (Pf11764) occurs via oxidative conversion to carbon dioxide and ammonia, the latter satisfying the nitrogen requirement. Substrate attack is initiated oxygenolytically by an enzyme referred to as cyanide oxygenase (CNO), which exhibits properties of a pterin-dependent hydroxylase. The pterin requirement for Pf11764 CNO was satisfied by supplying either the fully (tetrahydro) or partially (dihydro) reduced forms of various pterin compounds at catalytic concentrations (0.5 µM). These compounds included, for example, biopterin, monapterin and neopterin, all of which were also identified in cell extracts. A related CNO-mediated mechanism ... continued below

Creation Information

Dolghih, Elena May 2004.

Context

This thesis is part of the collection entitled: UNT Theses and Dissertations and was provided by UNT Libraries to Digital Library, a digital repository hosted by the UNT Libraries. It has been viewed 631 times . More information about this thesis can be viewed below.

Who

People and organizations associated with either the creation of this thesis or its content.

Chair

Committee Members

Publisher

Rights Holder

For guidance see Citations, Rights, Re-Use.

  • Dolghih, Elena

Provided By

UNT Libraries

With locations on the Denton campus of the University of North Texas and one in Dallas, UNT Libraries serves the school and the community by providing access to physical and online collections; The Portal to Texas History and UNT Digital Libraries; academic research, and much, much more.

Contact Us

What

Descriptive information to help identify this thesis. Follow the links below to find similar items on the Digital Library.

Degree Information

Description

Utilization of cyanide as the sole nitrogen source by Pseudomonas fluorescens NCIMB 11764 (Pf11764) occurs via oxidative conversion to carbon dioxide and ammonia, the latter satisfying the nitrogen requirement. Substrate attack is initiated oxygenolytically by an enzyme referred to as cyanide oxygenase (CNO), which exhibits properties of a pterin-dependent hydroxylase. The pterin requirement for Pf11764 CNO was satisfied by supplying either the fully (tetrahydro) or partially (dihydro) reduced forms of various pterin compounds at catalytic concentrations (0.5 µM). These compounds included, for example, biopterin, monapterin and neopterin, all of which were also identified in cell extracts. A related CNO-mediated mechanism of cyanide utilization was identified in cyanide-degrading P. putida BCN3. This conclusion was based on (i) the recovery of CO2 and NH3 as enzymatic reaction products, (ii) the dependency of substrate conversion on both O2 and NADH, and (iiii) utilization of cyanide, O2 and NADH in a 1:1:1 reaction stoichiometry. In contrast to findings reported for Pf11764, it was not possible to demonstrate a need for exogenously added pterin as a cofactor for the PpBCN3 enzyme system. However, results which showed that cells of PpBCN3 contained approximately seven times the amount of pterin as Pf11764 (of which a significant portion was protein-bound) were interpreted as indicating that sufficient bound CNO-cofactor exists, thus eliminating any need for a supplemental source.

Subjects

Language

Identifier

Unique identifying numbers for this thesis in the Digital Library or other systems.

Collections

This thesis is part of the following collection of related materials.

UNT Theses and Dissertations

Theses and dissertations represent a wealth of scholarly and artistic content created by masters and doctoral students in the degree-seeking process. Some ETDs in this collection are restricted to use by the UNT community.

What responsibilities do I have when using this thesis?

When

Dates and time periods associated with this thesis.

Creation Date

  • May 2004

Added to The UNT Digital Library

  • Feb. 15, 2008, 3:12 p.m.

Description Last Updated

  • Dec. 15, 2008, 10:40 a.m.

Usage Statistics

When was this thesis last used?

Yesterday: 0
Past 30 days: 3
Total Uses: 631

Interact With This Thesis

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

Citations, Rights, Re-Use

Dolghih, Elena. Bacterial Cyanide Assimilation: Pterin Cofactor and Enzymatic Requirements for Substrate Oxidation, thesis, May 2004; Denton, Texas. (digital.library.unt.edu/ark:/67531/metadc4525/: accessed September 23, 2017), University of North Texas Libraries, Digital Library, digital.library.unt.edu; .