Table 1.
Activity of r-α1-PI from E. coli and A. niger and evaluation of molecular weight of recombinant and plasma-derived species determined by MALDI-MS
| Protein | Activitya (%) | Molecular massb |
| pd-α1-PI (standard) | 100 | 50,300 |
| degly-pd-α1-PI | n.a.c | 44,210 |
| r-α1-PI/E. coli | 35d | 45,000e |
| r-α1-PI/A. niger | 76f,g | 50,100 |
aThe calculations were based on comparison with pdtαxtPI as a standard (100%) and using normalized equal concentrations of r-α1-PI samples as determined by ELISA; bmolecular weight is shown as a an average value measured for 2 samples; c not available; pd-α1-PI was enzymatically deglycosylated under denaturing conditions; d as measured for His-tagged r-α1-PI within 1.5 h after elution from the TALON beads; e as estimated by amino acid sequence for α1-PI without glycans; f shown for A. niger supernatant after Amicon 10 K filtration procedure; g the standard deviation of our potency assay is ± 15%.