Table 2.
Molecular weight analysis by mass spectrometry for purified fibulin-2 constructs.
| Construct | No. of cys | Disulfide bonds | MWtheor (Da) | MWexp (Da) | MWΔ (Da) |
|---|---|---|---|---|---|
| MH6M-S427-G545 (monomer) | 17 | – | 13,816 | – | – |
| MH6M-S427-G545 (dimer) | 34 | 17 | 27,632 | 27,598 | 34 |
| MH6M-S427-G545 (C500L) | 16 | 8 | 13,826 | 13,810 | 16 |
| MH6M-G592-Q710 | 12 | 6 | 13,827 | 13,815 | 12 |
| MH6M-D709-V802 | 12 | 6 | 11,575 | 11,563 | 12 |
| MH6M-T800-V896 | 12 | 6 | 11,660 | 11,649 | 12 |
| MH6M-V894-V981 | 12 | 6 | 10,710 | 10,697 | 12 |
| MH6M-E979-L1063 | 12 | 6 | 10,515 | 10,503 | 12 |
| MH6M-K1061-P1221 | 8 | 4 | 19,254 | 19,246 | 8 |
The theoretical average molecular weight (MWtheor) was calculated using ExPASy ProtParam tool 44 and compared with the experimentally determined average molecular weight (MWexp) of the purified NEM treated fibulin-2 constructs. A reduction of 2 daltons (Da) in the MWtheor is expected for the formation of each disulfide bond. MWΔ is the difference between MWtheor and MWexp.