Purification and characterization of NADPH--cytochrome c reductase from the midgut of the southern armyworm (Spodoptera eridania).
Biochem J
; 181(3): 593-605, 1979 Sep 01.
Article
de En
| MEDLINE
| ID: mdl-117798
ABSTRACT
1. NADPH-cytochrome c reductase was solubilized with bromelain and purified about 400-fold from sucrose/pyrophosphate-washed microsomal fractions from southern armyworm (Spodoptera eridania) larval midguts. 2. The enzyme has a mol.wt. of 70 035 +/- 1300 and contained 2 mol of flavin/mol of enzyme consisting of almost equimolar amounts of FMN and FAD. 3. Aerobic titration of the enzyme with NADPH caused the formation of a stable half-reduced state at 0.5 mol of NADPH/mol of flavin. 4. Kinetic analysis showed that the reduction of cytochrome c proceeded by a Bi Bi Ping Pong mechanism. 5. Apparent Km values for NADPH and cytochrome c and Ki values for NADP+ and 2'-AMP were considerably higher for the insect reductase than for the mammalian liver enzyme. 6. These are discussed in relation to possible differences in the active sites of the enzymes.
Texte intégral:
1
Collection:
01-internacional
Base de données:
MEDLINE
Sujet principal:
NADPH-ferrihemoprotéine reductase
/
Intestins
/
Lepidoptera
Limites:
Animals
Langue:
En
Journal:
Biochem J
Année:
1979
Type de document:
Article