Asp-Selective Microwave-Supported Acid Proteolysis - Proteomic and Metabolomic Approaches to Biomarker Discovery - page 227

(A)

2292.8

298.6

100
90
80
70
60
50
40
30
20
10
0

2241.2

2284.6

2235 2255 2275 2295 2315 2335

Mass (m/z)

(B)

300.3

100
90
80
70
60
50
40
30
20
10
0

2241.3

2293.0

2279.4

2263.5

2235 2255 2275 2295 2315 2335

Mass (m/z)

(C)

2302.1

277.2

100
90
80
70
60
50
40
30
20
10
0

2242.1 2264.2

2280.0
2284.5

2235 2255 2275 2295 2315 2335

Mass (m/z)

FIGURE 6 Mass spectra demonstrating the relative abundances of phenotype-specific peptides produced by Asp-selective
acid cleavage of blood samples containing different hemoglobin variants. Digestion of normal Hb (A) resulted in the expected
signature peptide (arrow). Digestion of two distinct phenotypes (B, C) demonstrates a signi

cant decrease in the relative
abundance of the signature peptide (arrow, diamond) and an increase in the Glu to Val substituted peptide (circle). (Reprinted
with permission from reference #10.)