Table 2.

Comparison of quantitative data obtained for in vitro glycated HSA and for in vivo glycated HSA^a

			Change Relative to K525
Digest	Mass (u)	Residueb	2 Week Sample	5 Week Sample	In vivo HSA [41]
Trypsin	1149.60	1-10 or K51c	0.50 (1)	0.93 (8)	3.3 (2)
Lys-C	2585.09	K262	0.61 (2)	0.57 (1)	1.2 (1)
Glu-C	1680.80	K475	0.74 (3)	0.70 (6)	7.6 (4)
Trypsin	2045.10	K378	0.75 (4)	0.78 (7)	10.8 (5)
Glu-C	1704.91	K162	0.77 (5)	0.65 (4)	59.9 (10)
Glu-C	2578.26	K64	0.79 (6)	0.68 (5)	7.4 (3)
Trypsin	1639.94	K414	0.82 (7)	0.60 (2)	11.5 (6)
Trypsin	1623.80	K335	0.83 (8)	0.95 (9)	27.5 (8)
Trypsin	1546.80	K276	0.94 (9)	0.63 (3)	46.7 (9)
Glu-C	1313.80	K525 or K524/K525	1.00 (10)	1.00 (10)	100 (11) or 13.5 (7)
Lys-C	1149.62	1-10 or K51c	1.04 (11)	1.14 (11)	3.3 (2)

^aThe in vivo results are based on data from Ref. [41]. The values for the in vitro samples were determined by comparing the glycated/control index for the indicated peptide to the same index for a peptide containing K525. The relative ranking is given in parenthesis and is in increasing order from 1-13. The values in italics represent residues that have a similar modification rank in all three samples. Values in bold represent residues that have a similar rank in the two week in vitro glycated HSA and in vivo glycated HSA. The underlined values represent residues that are similarly ranked in the five week in vitro glycated HSA and in vivo glycated HSA.

^bThe amino acid sequence for precursor HSA was used for peptide mapping in Ref. [41]. The listed sites were converted to those for the same amino acids in the sequence for mature HSA, as used in this current study, for the sake of consistency in the comparison.

^cThis particular ¹⁶O/¹⁸O ratio could correspond to either residues 1-10 or 42-51. These peptides could not be differentiated at the 50 ppm level of mass accuracy that was used as the cut-off in this report.