Role of. pi. -cation radicals in the enzymatic cycles of peroxidases, catalases, and nitrite and sulfite reductases

Conference · Tue Jan 01 00:00:00 EST 1980

OSTI ID:5277549

Hanson, L K; Chang, C K; Davis, M S; Fajer, J

Charge iterative extended Hueckel calculations, and magnetic and optical results on porphyrins, chlorins, and isobacteriochlorins (1) suggest that the catalytic cycles of the enzymes horseradish peroxidase, catalase, Neurospora crassa catalase, and nitrite and sulfite reductases proceed via ..pi..-cation radicals of their prosthetic groups; (2) offer distinguishing features for the optical and magnetic spectra of these radicals, pertinent to their detection as enzymatic intermediates; (3) reconcile the seemingly contradictory optical and NMR data on Compounds I of horseradish peroxidase; and (4) predict that the axial ligation of the heme differs for horseradish peroxidase and catalase.

• Research Organization: Brookhaven National Lab., Upton, NY (USA); Michigan State Univ., East Lansing (USA). Dept. of Chemistry
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 5277549
• Report Number(s): BNL-27860; CONF-800490-1
• Resource Relation: Conference: Symposium on interaction between iron and proteins in oxygen and electron transport, Airlie House, VA, USA, 13 Apr 1980
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
CATALYSIS
BIOCHEMICAL REACTION KINETICS
OXIDOREDUCTASES
PEROXIDASES
RADICALS
CATIONS
MAGNETIC PROPERTIES
OPTICAL PROPERTIES
PORPHYRINS
REACTION INTERMEDIATES
CARBOXYLIC ACIDS
CHARGED PARTICLES
ENZYMES
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
IONS
KINETICS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHYSICAL PROPERTIES
REACTION KINETICS
550200* - Biochemistry
400301 - Organic Chemistry- Chemical & Physicochemical Properties- (-1987)