Work

Flavohemoglobin Detoxifies Nitric Oxide in Aerobic, but Not Anaerobic, Escherichia coli

Year: 2002

Type: article

Abstract: Nitric-oxide dioxygenase (NOD) and reductase (NOR) activities of flavohemoglobin (flavoHb) have been suggested as mechanisms for NO metabolism and detoxification in a variety of microbes. Mechanisms of NO detoxification were tested in Escherichia coli using flavoHb-deficient mutants and overexpressors. flavoHb showed negligible anaerobic NOR activity and afforded no protection to the NO-sensitive aconitase or the growth of anoxic E. coli, whereas the NOD activity and the protection afforded with O(2) were substantial. A NO-inducible, O(2)-sensitive, and cyanide-resistant NOR activity efficiently metabolized NO and protected anaerobic cells from NO toxicity independent of the NOR activity of flavoHb. flavoHb possesses nitrosoglutathione and nitrite reductase activities that may account for the protection it affords against these agents. NO detoxification by flavoHb occurs most effectively via O(2)-dependent NO dioxygenation.

Source: Journal of Biological Chemistry

DOI: 10.1074/jbc.m110470200

Authors: Anne M. Gardner, Paul R. Gardner

Institution: Cincinnati Children's Hospital Medical Center

Language: English

Topic: Hemoglobin structure and function

Subfield: Biochemistry

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: hybrid

Estimated APC paid: $3,430

Funder: National Institute of General Medical Sciences