Cytochrome P-450 in liver microsomes of streptozotocin-induced diabetic rats: purification and characterization.
Two diabetes-inducible forms of cytochrome P-450, named P-450ST-1 and -ST-2, were purified from the liver microsomes of streptozotocin-diabetic male rats by sodium cholate solubilization, octylamino-Sepharose 4B chromatography and high-performance liquid chromatography with DEAE-5PW and hydroxyapatite columns. The purified P-450 forms gave a single band each on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, with an apparent molecular weight of 48,500 for P-450ST-1 or 48,000 for P-450ST-2. The CO-reduced spectral maxima of P-450ST-1 and -ST-2 were at 451 nm. The two cytochromes had the low-spin state of heme in the oxidized form. Both P-450ST-1 and -ST-2 catalyzed the metabolism of aniline, benzphetamine, p-nitroanisole, testosterone and aminopyrine. However, the catalytic activity of P-450ST-2 for these substrates was apparently higher than that of ST-1. Analyses of the NH2-terminal amino-acid sequence and Western immunoblot showed that P-450ST-1 and -ST-2 differed structurally from each other. The catalytic activities, molecular weights, NH2-terminal sequences and/or immunochemical properties of P-450ST-1 and -ST-2 did not agree with those of the other cytochrome P-450 forms purified from diabetic rats previously.
Toda
A
A
Department of Biochemistry, Faculty of Pharmaceutical Sciences, Fukuoka University, Japan.
Ogata
S
S
Nagamatsu
A
A
Shimeno
H
H
D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis / Q000302:isolation & purification / Q000378:metabolism*; D003921:Diabetes Mellitus, Experimental / Q000201:enzymology*; D004591:Electrophoresis, Polyacrylamide Gel; D004790:Enzyme Induction; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology*; D008969:Molecular Sequence Data; D051381:Rats; D017208:Rats, Wistar; D013311:Streptozocin
D013311:Streptozocin; D003577:Cytochrome P-450 Enzyme System