Suicide inactivation of catechol 2,3-dioxygenase from Pseudomonas putida mt-2 by 3-halocatechols

Journal Article · Thu Mar 01 04:00:00 EST 1984 · Appl. Environ. Microbiol.; (United States)

OSTI ID:6863945

Bartels, I; Knackmuss, H J; Reineke, W

The inactivation of catechol 2,3-dioxygenase from Pseudomonas putida mt-2 by 3-chloro- and 3-fluorocatechol and the iron-chelating agent Tiron (catechol-3,5-disulfonate) was studied. Whereas inactivation by Tiron is an oxygen-independent and mostly reversible process, inactivation by the 3-halocatechols was only observed in the presence of oxygen and was largely irreversible. The rate constants for inactivation (K/sub 2/) were 1.62 x 10/sup -3/ sec/sup -1/ for 3-chlorocatechol and 2.38 x 10/sup -3/ sec/sup -1/ for 3-fluorocatechol. The inhibitor constants (K/sub i/) were 23 ..mu..M for 3-chlorocatechol and 17 ..mu..M for 3-fluorocatechol. The kinetic data for 3-fluorocatechol could only be obtained in the presence of 2-mercaptoethanol. Besides inactivated enzyme, some 2-hydroxyhexa-2,4-dienoic acid as the actual suicide product of meta-cleavage. A side product of 3-fluorocatechol cleavage is a yellow compound with the spectral characteristics of a 2-hydroxy-6-oxohexa-2,4-dienoci acid indicating 1,6-cleavage. Rates of inactivation by 3-fluorocatechol were reduced in the presence of superoxide dismutase, catalase, formate, and mannitol, which implies that superoxide anion, hydrogen peroxide, and hydroxyl radical exhibit additional inactivation. 64 references.

• Research Organization: Gesellschaft fuer Strahlen und Umweltforschung mbH, Munich, West Germany
• OSTI ID: 6863945
• Journal Information: Appl. Environ. Microbiol.; (United States), Journal Name: Appl. Environ. Microbiol.; (United States) Vol. 47:3; ISSN AEMID
• Country of Publication: United States
• Language: English

Related Subjects

560302* -- Chemicals Metabolism & Toxicology-- Microorganisms-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AROMATICS
BACTERIA
BIOLOGICAL EFFECTS
DEVELOPERS
ENZYMES
FLUORINE COMPOUNDS
HALOGEN COMPOUNDS
HYDROXY COMPOUNDS
INACTIVATION
KINETICS
METABOLISM
MICROORGANISMS
ORGANIC COMPOUNDS
OXIDOREDUCTASES
OXYGENASES
PHENOLS
POLYPHENOLS
PSEUDOMONAS
PYROCATECHOL