TABLE 2

Relative initial activities of wild-type and mutated KshA1N with a range of steroid substrates

Steroid substrateRelative initial activity of Ksh (%)a
A1NA1V207TA1P210EA1D225RA1N238D
4-Androstene-3,17-dione (AD)100100100100100
4-Androstene-17β-ol-3-one (testosterone)135 ± 10161 ± 30154 ± 20133 ± 37139 ± 24
1,4-Androstadiene-3,17-dione (ADD)282 ± 40289 ± 38275 ± 47178 ± 29252 ± 50
1,4-Androstadiene-17β-ol-3-one (boldenone)252 ± 31258 ± 33255 ± 51174 ± 18267 ± 29
1-(5α)-Androstene-3,17-dione91 ± 19112 ± 20100 ± 2263 ± 1895 ± 27
5α-Androstane-3,17-dione23 ± 432 ± 1632 ± 6NDc26 ± 9
5β-Androstane-3,17-dione33 ± 642 ± 1841 ± 1215 ± 552 ± 19
5α-Androstane-17β-ol-3-one (androstanolone)18 ± 335 ± 1113 ± 7ND25 ± 9
17α-Methyl-1-(5α)-androstane-17β-ol-3-one78 ± 892 ± 2182 ± 1032 ± 1373 ± 32
4-Androstene-3,17-dione-19-ol10 ± 212 ± 416 ± 2NDND
4-Pregnene-3,20-dione (progesterone)335 ± 38430 ± 55323 ± 40215 ± 61320 ± 40
11β-Hydrocortisone52 ± 982 ± 2642 ± 1122 ± 857 ± 19
23,24-Bisnorchol-4-ene-22-oic acid (4-BNC)426 ± 52499 ± 58447 ± 65260 ± 43440 ± 52
4-Cholestene-3-oneb (cholestenone)21 ± 256 ± 1730 ± 9ND25 ± 12
  • a Relative activity signifies the percentage of activity toward substrates at 200 μM relative to that of AD, which was set at 100%. Errors were calculated as standard errors of the means (from three experiments).

  • b Steroid concentration of 25 μM due to the low solubility of cholesterone.

  • c ND, no detectable activity toward specific steroid.