Table III.

SAA proteoforms identified using targeted mass spectrometric immunoassay

SAA proteoform		Theoretical [M+H]+	Observed [M+H]+	Frequency [%]	c(SAA) [mg/L]
Native SAA proteoforms
SAA 1.1	native SAA 1.1	11,682.7	11,683.7	99.4	3.15 (0.398 – 22.3)
SAA 1.3	native SAA 1.3	11,654.6	11,655.2	11.2	1.60 (0.673 – 4.25)
SAA 2.1	native SAA 2.1	11,628.7	11,629.1	57.6	0.969 (0.259 – 5.01)
SAA 2.2	native SAA 2.2	11,647.7	11,648.6	11.8	1.69 (0.382 – 7.38)
Truncated SAA proteoforms
SAA 1.1 R	1.1 lacking 1 N-terminal (R-) amino acid	11,526.5	11,526.8	99.4	2.61 (0.396 – 13.4)
SAA 1.1 RS	1.1 lacking N-terminal dipeptide (RS-)	11,439.4	11,439.4	99.4	0.907 (0.344 – 6.67)
SAA 1.1 RSFF	1.1 lacking N-terminal tetra peptide (RSFF-)	11,147.1	11,146.4	11.8	0.269 (0.0851 – 0.812)
SAA 1.1 RSFFS	1.1 lacking N-terminal penta peptide (RSFFS-)	11,058.9	11,058.7	7.06	0.157 (0.101 – 0.395)
SAA 1.3 R	1.3 lacking 1 N-terminal (R-) amino acid	11,498.4	11,498.5	11.2	1.53 (0.711 – 3.79)
SAA 1.3 RS	1.3 lacking N-terminal dipeptide (RS-)	11,411.4	11,411.2	10.6	0.696 (0.253 – 1.69)
SAA 1.3 RSFF	1.3 lacking N-terminal tetra peptide (RSFF-)	11,117.0	11,116.9	1.18	0.231 (0.219 – 0.244)
SAA 2.1 R	2.1 lacking 1 N-terminal (R-) amino acid	11,472.5	11,472.6	57.6	0.894 (0.219 – 3.16)
SAA 2.1 RS	2.1 lacking N-terminal dipeptide (RS-)	11,385.4	11,384.9	42.9	0.456 (0.219 – 1.35)
SAA 2.1 RSFF	2.1 lacking N-terminal tetra peptide (RSFF-)	11,091.1	11,092.8	2.35	0.139 (0.103 – 0.160)
SAA 2.2 R	2.2 lacking 1 terminal (R-) amino acid	11,491.5	11,492.0	12.4	1.23 (0.344 – 4.44)
SAA 2.2 RS	2.2 lacking N-terminal dipeptide (RS-)	11,404.5	11,403.2	8.23	0.481 (0.219 – 1.35)