Purification from adult pig testicular P-450 and 17 alpha-hydroxylase activity of P-450 containing liposomal membranes.
A cytochrome P-450 from adult pig testicular microsomes was purified to a specific content of 12 nmol P-450/mg protein. P-450 has a minimum molecular weight of 46000 +/- 1000, as judged on sodium dodecyl sulfate polyacrylamide gel electrophoresis. Adult testicular P-450 is prepared in the low-spin form with an absorbance maximum at 417 nm. The substrate-induced difference spectrum with progesterone is a typical I difference spectrum. P-450 was incorporated into liposomal membranes composed of phosphatidylcholine, and 17 alpha-hydroxylase activity was shown to amount to 15.5 nmol product/min/nmol of P-450. Furthermore, testicular cytochrome b 5 did not increase the 17 alpha-hydroxylase activity, and the activity was largely inhibited by the addition of sodium cholate, Emulgen 913 and testicular lipid.
Kuwada
M
M
Department of Biochemistry, School of Medicine, Kitasato University, Kanagawa, Japan.
Sone
Y
Y
Kitajima
R
R
D000818:Animals; D002852:Chromatography, Ion Exchange; D003577:Cytochrome P-450 Enzyme System / Q000302:isolation & purification* / Q000378:metabolism; D007700:Kinetics; D008081:Liposomes / Q000302:isolation & purification / Q000378:metabolism; D008297:Male; D008861:Microsomes / Q000201:enzymology*; D010713:Phosphatidylcholines / Q000302:isolation & purification / Q000378:metabolism; D013053:Spectrophotometry; D013254:Steroid 17-alpha-Hydroxylase / Q000302:isolation & purification* / Q000378:metabolism; D013379:Substrate Specificity; D013552:Swine; D013737:Testis / Q000201:enzymology*
D008081:Liposomes; D010713:Phosphatidylcholines; D003577:Cytochrome P-450 Enzyme System; D013254:Steroid 17-alpha-Hydroxylase; C022445:progesterone 17-alpha-hydroxylase