Table 2.
Site-specific MG modifications in vitro.
| Protein | Accession | Site | Peptide Sequence | MG-HI (R+54) | MG-DH (R+72) |
|---|---|---|---|---|---|
| Albumin | P02768 | R81 | LCTVATLRETYGEMADCCAK | X | X |
| R117 | LVRPEVDVMCTAFHDNEETFLK[K] | X | X | ||
| R186 | LDELRDEG[K]ASSAK | X | X | ||
| R218 | AWAVARLSQR | X | X | ||
| R257 | VHTECCHGDLLECADDRADLAK | X | X | ||
| R410 | FQNALLVRYTK | X | X | ||
| R428 | [K]VPQVSTPTLVEVSRNLGK | X | X | ||
| R472 | TPVSDRVTK | X | |||
| R445 | RMPCAEDYLSVVLNQLCVLHEK | X | |||
| Serotransferrin | P02787 | R124 | SCHTGLGRSAGWNIPIGLLYCDLPEPR | X | |
| Haptoglobin | P00738 | R41 | LRTEGDGVYTLNDK[K] | X | X |
| R243 | VSVNERVMPICLPS[K]DYAEVGR | X | |||
| Hemopexin | P02790 | R185 | YYCFQGNQFLRFDPVR | X | |
| Ig lambda-2 | P0CG05 | R83 | SHRSYSCQVTHEGSTVEK | X | |
| chain C regions |
Spectra were identified for the R+54 adduct using human plasma or pure protein incubated with 500 μM MG. Spectra containing the intermediate R+72 dihydroimidazolidine adduct are indicated. All cysteines are carbamidomethylated (C+57) prior to digestion. Brackets indicate alternate cleavage peptides detected.
MG-DH: methylglyoxal-derived dihydroxyimidazolidine
MG-HI: methylglyoxal-derived hydroimidazolone