Table 7.
Total activity and unit of activity (nmol hydroxytestosterone/nmol P450/h) of testosterone hydroxylation by CYP102A1 M11 mutants and wild-type CYP102A1
| No. | Residue | Metabolite formationa | |||
|---|---|---|---|---|---|
| 15β-OH-T | 16β-OH-T | 2β-OH-T | Total activitya | ||
| Nonpolar side chain | |||||
| 1 | Phe87 | 86 | 275 | 499 | 860 |
| 2 | Gly87 | 31 | 13 | 12 | 56 |
| 3 | Ala87 | 356 | 25 | 244 | 625 |
| 4 | Leu87 | 2 | 9 | 35 | 46 |
| 5 | Ile87 | 21 | 597 | 92 | 710 |
| 6 | Val87b | 641 | 351 | 218 | 1,210 |
| 7 | Met87 | 11 | 33 | 36 | 81 |
| 8 | Pro87 | – | – | – | – |
| 9 | Trp87 | 15 | 6 | 8 | 29 |
| Uncharged polar side chain | |||||
| 10 | Ser87 | – | – | – | – |
| 11 | Thr87 | 126 | 367 | 557 | 1,050 |
| 12 | Asn87 | ND | ND | 35 | 35 |
| 13 | Gln87 | 21 | ND | 119 | 140 |
| 14 | Tyr87 | 625 | 288 | 337 | 1,250 |
| 15 | Cys87 | 1 | ND | 4 | 5 |
| Charged polar side chain | |||||
| 16 | Lys87 | 3 | 9 | 13 | 25 |
| 17 | Arg87 | 32 | ND | 33 | 65 |
| 18 | His87 | 40 | ND | 135 | 175 |
| 19 | Asp87 | – | – | – | – |
| 20 | Glu87 | – | – | – | – |
| 21 | Wild type (Phe87) | ND | ND | ND | ND |
15β-OH-T 15β-hydroxytestosterone, 16β-OH-T 16β-hydroxytestosterone, 2β-OH-T 2β-hydroxytestosterone, ND not detectable
aSpecific activities observed with 0.5 mM testosterone and 200 nM P450 BM3. The values represent averages of two measurements; variability was always less than 10%
bCYP102A1 M11 containing R47L, E64G, F81I, F87V, E143G, L188Q, E267V, and G415S [22]