Table 1.
11β-HSD1 | 11β-HSD2 | |
---|---|---|
Enzyme family | SDR superfamily | |
Size gene | 30 kb, 6 exons | 6·2 kb, 5 exons |
Size of the enzyme molecule | 292 aa, 34 kDa | 405 aa, 44 kDa |
Enzyme kinetics | In vitro bidirectional Oxidation of cortisol to cortisone (11β-dehydrogenase) |
Only dehydrogenase |
Reduction of cortisone to cortisol (11-oxoreductase) In vivo mainly reductase | ||
High affinity | Low for cortisol (Km-µM) High for cortisone (Km-nM) |
High for cortisol (Km-nM) |
Cofactor | NADP(H) | NAD |
Tissue expression | Liver, brain, pancreas, adipose, lungs, gonads, bones | Kidney, colon, salivary glands, placenta |
Function | Supplies cortisol to GR | Protects MR from cortisol |