In vivo metal substitution in bacteroides superoxide dismutase

The effect of various growth conditions on the type of superoxide dismutase (SGD) formed anaerobically in three Bacteriodes species was studied. B. fragilis, B. distasonis, and B. thetaiotaomicron were grown in ironâ restricted media with or without manganese supplementation. Iron availability was decreased by treatment of the media with chelex-100, a metal-chelating resin, and addition of desferrioxamine mesylate (desferal, Ciba-Geigy), an iron chelator. Mn-containing (MnSOD) and Fe-containing superoxide dismutase (EeSOD) activities in cell extracts were differentiated by inhibition with azide and inactivation by H₂0₂. The amount of Mn-containing superoxide dismutase was estimated by the fraction of azide- and H₂0₂, -resistant activity. Cells grown in untreated media contained approximately 90% FeSOD and 10% MnSOD. Cells grown in Fe-restricted media supplemented with graded amounts of manganese synthesized a progressively larger fraction of MnSOD. Hemin, added to the Fe-restricted media, did not serve as an iron source for FeSOD formation. Superoxide dismutase specific activities varied (3-6 U/mg) in each extract but not as a function of manganese concentration.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Biochemistry and Nutrition

Department dc:contributor.department

Biochemistry and Nutrition

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1989

Author dc:creator

• Chen, Ying

Chair dc:contributor.committeechair

• Gregory, Eugene M.

Committee members dc:contributor.committeemember

• Bevan, David R.
• Hess, John L.

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

etd-09082012-040038

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/44628