Abstract
Cytochrome P450 17A1 (CYP17A1) catalyzes the synthesis of androgens from the steroid precursors pregnenolone and progesterone in a two-step reaction process: allylic hydroxylation and carbo-carbon bond scission. Cytochrome b5 (Cyt-b5) is a stimulator of the second lyase reaction, but the chemical mechanism is unclear. We have shown previously that this stimulatory effect requires redox active Cyt-b5. To investigate the origin of the lyase reaction enhancement by electron transfer from Cyt-b5, we measured the reduction rates of oxy-ferrous substrate-bound CYP17A1 by Cyt-b5 and by cytochrome P450 reductase (CPR) coincorporated in Nanodiscs using stopped flow spectroscopy. We observed that Cyt-b5 reduces oxy-ferrous CYP17A1 10-fold faster than CPR, with the rate similar to that observed in a ternary complex of all three proteins.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 2282-2288 |
| Number of pages | 7 |
| Journal | FEBS Letters |
| Volume | 592 |
| Issue number | 13 |
| DOIs | |
| State | Published - Jul 1 2018 |
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Keywords
- Nanodisc
- androgen biosynthesis
- cytochrome P450
- cytochrome b5
ASJC Scopus subject areas
- Biophysics
- Structural Biology
- Biochemistry
- Molecular Biology
- Genetics
- Cell Biology
Cite this
Cytochrome b5 enhances androgen synthesis by rapidly reducing the CYP17A1 oxy-complex in the lyase step. / Duggal, Ruchia; Denisov, Ilia G.; Sligar, Stephen.
In: FEBS Letters, Vol. 592, No. 13, 01.07.2018, p. 2282-2288.Research output: Contribution to journal › Letter
}
TY - JOUR
T1 - Cytochrome b5 enhances androgen synthesis by rapidly reducing the CYP17A1 oxy-complex in the lyase step
AU - Duggal, Ruchia
AU - Denisov, Ilia G.
AU - Sligar, Stephen
PY - 2018/7/1
Y1 - 2018/7/1
N2 - Cytochrome P450 17A1 (CYP17A1) catalyzes the synthesis of androgens from the steroid precursors pregnenolone and progesterone in a two-step reaction process: allylic hydroxylation and carbo-carbon bond scission. Cytochrome b5 (Cyt-b5) is a stimulator of the second lyase reaction, but the chemical mechanism is unclear. We have shown previously that this stimulatory effect requires redox active Cyt-b5. To investigate the origin of the lyase reaction enhancement by electron transfer from Cyt-b5, we measured the reduction rates of oxy-ferrous substrate-bound CYP17A1 by Cyt-b5 and by cytochrome P450 reductase (CPR) coincorporated in Nanodiscs using stopped flow spectroscopy. We observed that Cyt-b5 reduces oxy-ferrous CYP17A1 10-fold faster than CPR, with the rate similar to that observed in a ternary complex of all three proteins.
AB - Cytochrome P450 17A1 (CYP17A1) catalyzes the synthesis of androgens from the steroid precursors pregnenolone and progesterone in a two-step reaction process: allylic hydroxylation and carbo-carbon bond scission. Cytochrome b5 (Cyt-b5) is a stimulator of the second lyase reaction, but the chemical mechanism is unclear. We have shown previously that this stimulatory effect requires redox active Cyt-b5. To investigate the origin of the lyase reaction enhancement by electron transfer from Cyt-b5, we measured the reduction rates of oxy-ferrous substrate-bound CYP17A1 by Cyt-b5 and by cytochrome P450 reductase (CPR) coincorporated in Nanodiscs using stopped flow spectroscopy. We observed that Cyt-b5 reduces oxy-ferrous CYP17A1 10-fold faster than CPR, with the rate similar to that observed in a ternary complex of all three proteins.
KW - Nanodisc
KW - androgen biosynthesis
KW - cytochrome P450
KW - cytochrome b5
UR - http://www.scopus.com/inward/record.url?scp=85050164828&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85050164828&partnerID=8YFLogxK
U2 - 10.1002/1873-3468.13153
DO - 10.1002/1873-3468.13153
M3 - Letter
VL - 592
SP - 2282
EP - 2288
JO - FEBS Letters
JF - FEBS Letters
SN - 0014-5793
IS - 13
ER -