Table 2. Comparison of Calculated and Experimental Molecular Masses for the Different sGC Constructs Determined by Nano-ESI/MS and Nano-ESI/MS/MS.
| construct | calculated mass (Da)a | calculated mass (Da)b | experimental mass (Da) |
|---|---|---|---|
| αGC(466–690) (monomer) | 24671.2 | 24687.5 | 24740.8 ± 17.9 (10 μM)e |
| αGC(466–661) (monomer)c | 21621.7 | 21636.1 | 21642.9 ± 18.3 (10 μM)e |
| αGC(466–690) (dimer) | 49342.4 | 49375 | 49489 ± 20.3 (10 μM)e |
| αGC(466–662) (dimer)d | 43499.6 | 43528.6 | 43500.1 ± 55.4 (10 μM) |
| αGC(466–661) (dimer) | 43243.4 | 43272.2 | 43403.1 ± 5.5 (10 μM) |
| βGC(407–626) (monomer) | 24769.2 | 24785.2 | 24820.5 ± 47.8 (10 μM)e |
| βGC(407–626) (dimer) | 49538.4 | 49570.4 | 49636.7 ± 36.6 (10 μM) |
| βGC(407–626) (tetramer) | 99076.8 | 99140.8 | 99929.9 ± 68.7 (10 μM) |
| αβGC (heterodimer) |
49440.4 | 49472.7 | 49660.2 ± 38.7 (10 μM) |
| αGC661βGC (heterodimer)c | 46390.9 | 46421.3 | 46449.5 ± 20.2 (10 μM) |
a
Monoisotopic masses were calculated from amino acid sequences with PeptideMass66 from the Expasy Web site.
b
Average masses were calculated from amino acid sequences with PeptideMass66 from the Expasy Web site.
c
Species obtained by introducing a stop codon at position 662 in the αGC(466–690) construct.
d
Species obtained by cleavage of αGC(466–690) at the N- and C-terminal TEV cleavage sites.
e
Measured mass obtained from nano-ESI/MS/MS at a SID voltage of 100 V.