17a-Hydroxylase/C 17,20 lyase

The zona fasciculata and zona reticularis produce and secrete 17a-hydroxypregnenolone, the main precursor of the adrenal androgens. A microsomal 17a-hydroxylase/ C-17,20-lyase (P-450ci7) enzyme converts 17a-... 

Cyclopropylamino)-androst-5-en-3(3-ol, a selective mechanism-based inhibitor of cytochrome P45017a(steroid 17a-hydroxylase/C 17-20 lyase). Biochem. Biophys. Res. Commun. 162, 1571-1577. 

A. Palusczak, M. Palzer, V Huch et al. (2000). Synthesis and evaluation of 17-aliphatic hetero-cycle-substituted steroidal inhibitors of 17a-hydroxylase/C 17-20-lyase (P450 17). J. Med. Chem. 43, 4437-4445. 

Zhang R Han XG, Mellon SH, Hall PF (1996) Expression of the gene for cytochrome P-450 17a-hydroxylase/C 17-20 lyase (CYP17) in porcine Leydig cells identification of a DNA sequence that mediates cAMP response. Biochim Biophys Acta 1307 73-82... 

Haidar S, Ehmer PB, Barassin S, Batzl-Hartmann C, Hartmann RW (2003) Effects of novel 17a-hydroxylase/C 17,20-lyase (P450 17, CYP 17) inhibitors on androgen biosynthesis in vitro and in vivo. J Steroid Biochem Mol Biol 84 555-562 Matsunaga N, Kaku T, Itoh F, Tanaka T, Kara T, Miki H, Iwasaki M, Aono T, Yamaoka M, Ku-saka M, Tasaka A (2004) C17,20-lyase inhibitors I. Structure-based de novo design and SAR study of C17,20-lyase inhibitors. Bioorg Med Chem 12 2251-2273... 

Fig. 45.3. Biosynthesis of androgens and other sex steroid hormones. The enzymes involved in this biosynthesis are (a) side-chain cleavage, (b) 17a-hydroxylase (c) 5-ene-3(3-hydroxysteroid dehydrogenase, (d) 3-oxosteroid-4,5-isomerase, (e) 17,20-lyase, (f) 17(3-hydroxysteroid dehydrogenase, (g) aromatase, (h) estradiol dehydrogenase, and (i) 5a-reductase.

---