Table 3.
Summary of effects on enzymatic activity and glycosylation for all PAM variants that were functionally tested
| PAM variant | PHM activity (% WT) | PAL activity (% WT) | PNGaseF (N-sugars) | Neuraminidase (sialic acid) |
|---|---|---|---|---|
|
| ||||
| WT | 100 ± 2 | 100 ± 3 | yes | yes |
| Val27Ile | 79 ± 6 | 103 ± 15 | (yes) | (yes) |
| Phe31Tyr | 76 ± 16 | 84 ± 1 | (yes) | (yes) |
| Val49Leu | 80 ± 26 | 93 ± 1 | (yes) | (yes) |
| Arg80Gln | 75 ± 6 | 87 ± 9 | (yes) | (yes) |
| Thr189Ile † | 6 ± 3** | 23 ± 5** | yes | no |
| His240Tyr | 111 ± 24 | 98 ± 22 | yes | no |
| Val244Ala | 113 ± 32 | 80 ± 10 | (yes) | (yes) |
| Pro412Leu | 81 ± 32 | 85 ± 28 | (yes) | (yes) |
| Ile452Val | 112 ± 45 | 113 ± 30 | (yes) | (yes) |
| Glu491Asp | 133 ± 75 | 138 ± 55 | (yes) | (yes) |
| His529Arg † | 41 ± 13 | 7 ± 1** | n.a. | n.a. |
| Ser539Trp | 49 ± 7** | 0 ± 1** | yes | no |
| Gly552Arg | 41 ± 6** | 6 ± 2** | yes | no |
| Asp563Gly | 44 ± 8** | 14 ± 3** | yes | no |
| Gly641Arg | 104 ± 0 | 116 ± 10 | (yes) | (yes) |
| Arg703Gln | 92 ± 17 | 0 ± 1** | yes | yes |
| Phe759Ser | 110 ± 25 | 12 ± 3** | yes | no |
| His778fs | 23 ± 3** | 0 ± 1** | n.a. | n.a. |
| Gly796Glu † | 55 ± 8 | 4 ± 1** | (yes) | (yes) |
Values are presented as mean ± SEM.
n.a., not assessed; WT, wild-type; (yes), based on SDS-PAGE profile.
†
Engineered inactive mutants.
**
p < 0.0001.