Related Experiment Video

Updated: May 30, 2026

Monitoring the Reductive and Oxidative Half-Reactions of a Flavin-Dependent Monooxygenase using Stopped-Flow Spectrophotometry
12:08

Monitoring the Reductive and Oxidative Half-Reactions of a Flavin-Dependent Monooxygenase using Stopped-Flow Spectrophotometry

Published on: March 18, 2012

Regulated O2 activation in flavin-dependent monooxygenases

Rosanne E Frederick1, Jeffery A Mayfield, Jennifer L DuBois

  • 1Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States.

Journal of the American Chemical Society
|July 22, 2011
PubMed

Insights

Flavin-dependent monooxygenases (FMOs) in Aspergillus fumigatus achieve specificity through L-arginine regulation. This discovery offers potential drug targets against fungal infections.

Area of Science:

  • Biochemistry
  • Mycology
  • Drug Discovery

Background:

  • Flavin-dependent monooxygenases (FMOs) are crucial in microbial biosynthesis, including siderophore production for iron acquisition in pathogens.
  • The FMO from Aspergillus fumigatus (Af-OMO) exhibits unusual substrate specificity compared to promiscuous mammalian homologs.

Purpose of the Study:

  • To elucidate the mechanism behind the high specificity of Af-OMO in biosynthetic pathways.
  • To identify potential regulatory mechanisms controlling FMO activity in fungi.
  • To explore Af-OMO as a drug target against Aspergillus fumigatus.

Main Methods:

  • Comparative mechanistic analysis of Af-OMO and mammalian FMOs.
  • Biochemical assays to study the effect of L-arginine on Af-OMO activity.
  • Investigation of iron acquisition pathways and gene knockout phenotypes in Aspergillus fumigatus.

Main Results:

  • Af-OMO demonstrates significantly enhanced O(2) activation rates in the presence of L-arginine, acting as a small molecule regulator.
  • This regulation mechanism provides insight into how biosynthetic FMOs couple O(2) activation with substrate hydroxylation.
  • Af-OMO is essential for Aspergillus fumigatus, and its gene knockout results in avirulence.

Conclusions:

  • L-arginine-mediated regulation is key to Af-OMO's specificity and function.
  • Inhibitors targeting Af-OMO represent promising therapeutic strategies against invasive fungal infections caused by Aspergillus fumigatus.

More Related Videos

Simultaneous Measurement of Superoxide/Hydrogen Peroxide and NADH Production by Flavin-containing Mitochondrial Dehydrogenases08:57

Simultaneous Measurement of Superoxide/Hydrogen Peroxide and NADH Production by Flavin-containing Mitochondrial Dehydrogenases

Published on: February 24, 2018

Anaerobic Protein Purification and Kinetic Analysis via Oxygen Electrode for Studying DesB Dioxygenase Activity and Inhibition08:31

Anaerobic Protein Purification and Kinetic Analysis via Oxygen Electrode for Studying DesB Dioxygenase Activity and Inhibition

Published on: October 3, 2018

Related Concept Videos

Oxidation of Phenols to Quinones01:17

Oxidation of Phenols to Quinones

In the presence of oxidizing agents, phenols are oxidized to quinones. Quinones can be easily reduced back to phenols using mild reducing agents. The electron-donating hydroxyl group enhances the reactivity of the aromatic ring, enabling oxidation of the ring even in the absence of an α hydrogen.
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox property is crucial in...
Oxidative Cleavage of Alkenes: Ozonolysis01:46

Oxidative Cleavage of Alkenes: Ozonolysis

In ozonolysis, ozone is used to cleave a carbon–carbon double bond to form aldehydes and ketones, or carboxylic acids, depending on the work-up.
Ozone is a symmetrical bent molecule stabilized by a resonance structure.
Phase I Oxidative Reactions: Overview01:19

Phase I Oxidative Reactions: Overview

Phase I biotransformation, or functionalization, is a crucial chemical process that converts drugs and other xenobiotics into more water-soluble forms, facilitating expulsion from the body. It involves oxidative, reductive, and hydrolytic reactions that add or unveil polar functional groups on lipophilic substrates. Key players in phase I reactions are the mixed-function oxidases. Situated in liver cell microsomes, these enzymes predominantly carry out drug metabolism. They require molecular...
Oxidation and Reduction of Organic Molecules01:19

Oxidation and Reduction of Organic Molecules

Energy production within a cell involves many coordinated chemical pathways. Most of these pathways are combinations of oxidation and reduction reactions, which occur at the same time. An oxidation reaction strips an electron from an atom in a compound, and the addition of this electron to another compound is a reduction reaction. Because oxidation and reduction usually occur together, these pairs of reactions are called redox reactions.
The removal of an electron from a molecule, results in a...
Oxygen Requirements and Growth Patterns01:29

Oxygen Requirements and Growth Patterns

Microorganisms exhibit diverse oxygen requirements and growth patterns driven by their metabolic strategies and environmental adaptations. Oxygen, while essential for many organisms, can also be toxic under certain conditions, shaping how microorganisms grow and survive.Oxygen Requirements of MicroorganismsMicroorganisms are classified based on their ability to use or tolerate oxygen:● Obligate aerobes like Mycobacterium tuberculosis need oxygen for energy production, as it serves as the...
Oxygen Transport in the Blood01:27

Oxygen Transport in the Blood

Hemoglobin (Hb) is a crucial molecule in the human body, consisting of four polypeptide chains, each bound to an iron-containing heme group. This unique structure enables hemoglobin to bind to oxygen, with each molecule capable of combining with four molecules of oxygen, leading to rapid and reversible oxygen loading. When fully loaded with oxygen, it is called oxyhemoglobin, while hemoglobin that has released oxygen is called reduced hemoglobin or deoxyhemoglobin. As hemoglobin binds oxygen,...