Insulin glycation by methylglyoxal results in native-like aggregation and inhibition of fibril formation

BMC Biochemistry

Table 1 Assignment of glycated amino acid residues.

Observed mass (Da)	Theoretical mass (Da)	Peptide sequence	Mass Increase (Da)	MAGE	Glycated residue
934.496	880.435	LVCGER GF (41-48)	54.061	MGH	R46
991.521	937.456	LVC*GER GF (41-48)	54.040	MGH	R46
1138.590	1084.524	LVCGER GFF (41-49)	54.066	MGH	R46
1171.590	1027.503	LVCGER GFF (41-49)	144.087	THP	R46
1228.616	1084.524	LVC*GER GFF (41-49)	144.092	THP	R46

In all cases, the observed peptide mass has a mass increment specific of a methylglyoxal-derived AGE modification. The specific MAGE are indicated in the table and the modified amino acid residues are highlighted in the peptide sequence. (MGH - hydroimidazolone; THP - tetrahydropyrimidine)
*peptide with cysteine alquilation.

ISSN: 1471-2091