Table III.
Enzymatic activity of soluble and insoluble protein extracts of COS-7 cells transfected with AKR1B expression vectors
| Soluble protein fraction with 500μM p-nitrobenzaldehyde | ||
|---|---|---|
| Activity (μmol/min/μg)a | Fold increase vs untransfected | |
| Untransfected COS7 cells | 3.0×10−5 | 1 |
| AKR1B15 transfected COS7cells | 9.4×10−5 | 3.1 |
| AKr1b16 transfected COS7cells | 2.90×10−5 | 1 |
| AKR1B10 transfected COS 7 cells | 6.2×10−4 | 21 |
| Insoluble fraction with 500μM p-nitrobenzaldehyde | ||
| Activity (μM/min/μg) | Fold increase vs untransfected | |
| Untransfected COS7 cells | 1.3×10−5 | 1 |
| AKR1B15 transfected COS7cells | 6.3×10−5 | 4.8 |
| Akr1b16 transfected COS 7 cells | 1.4×10−5 | 1 |
| Insoluble fraction with 10mM DL-glyceraldehyde | ||
| Activity (μM/min/μg) | Fold increase vs untransfected | |
| Untransfected COS7 cells | 3.8×10−5 | 1 |
| AKR1B15 transfected COS7cells | 6.9×10−5 | 1.8 |
| Ar1b16 transfected COS7cells | 3.6×10−5 | 1 |
a
160μg of supernatant (soluble protein fraction) or 100,000xg pellet dissolved in 0.1% triton (insoluble fraction) were used for activity measurements in the presence of 175μM NADPH and respective substrates in 0.1M phosphate buffer pH7.0. The rate of decrease in absorbance at 340nm was recorded and activity reported as μM/min/μg protein.