Table 1.
Mass spectromic analysis of ATCase c chain variants
| Variant | MVcalc (with Met) | MWcalc (without Met) | MWobs | N-terminal processing (%) |
| A32/A32-NKVNa | 35587.81 | 35456.62 | 35457 | >95 |
| Q137/S131 | 34483.63 | 34352.44 | 34484 | <5 |
| Q137/T136 | 35061.16 | 34929.27 | 35063 | <5 |
| Q137/T136-HKVN | 35539.71 | 35408.52 | 35544 | <5 |
| V169/S171-LR | 35653.93 | 35522.74 | 35522 | ∼50 |
| 35653 | ||||
| H170/T173-HKVN | 35978.26 | 35847.07 | 35980 | <5 |
| I215/E217-VR | 35687.87 | 35556.68 | 35688 | <5 |
| R54/T53-LRb | 35664.67 | 35533.48 | 35664 | <5 |
| R56/R54-IRb | 35563.56 | 35432.37 | 35564 | <5 |
a Nomenclature is according to Graf and Schachman (1996). The N-terminal residue (excluding initiator Met) and its position in the wild-type c chain sequence are given, followed by the last residue and its position, then any extra residues encoded by the triple frame stop codons. Thus, the wild-type sequence would be denoted as A1/L310.
b Linker to express these chains included GSHHHHHH, which differs from that, SGELDM, reported earlier (Yang and Schachman 1993; Graf and Schachman 1996).