Table 2.

Relative abundances of doubly cysteinylated IgG2-A form (%2Cys) in endogenous IgG2s purified from healthy human serum. XIC_{doubly cysteinylated} and XIC_{classically linked} are the extracted ion chromatogram peak areas of the precursor/product ion transitions for the doubly cysteinylated and classically linked IgG2-A Lys-C dipeptides, respectively. Demographic information corresponding to each human subject is included. There was no obvious correlation between hinge cysteinylation levels and age, gender or race, granted the sample size was small

Gender	Race	Age	XICclassically linked	XICdoubly cysteinylated	%2Cys
Male	White	52	21214823	96558	0.5
Male	Hispanic	66	15023572	139367	0.9
Male	White	59	9312008	78597	0.8
Male	Black	58	15631974	94021	0.6
Male	White	44	17710870	159266	0.9
Female	White	44	25823084	160364	0.6
Female	Hispanic	63	17255965	204560	1.2
Female	White	63	23764328	142695	0.6
Female	White	58	15456256	72583	0.5
Female	Black	63	17672827	229390	1.3
			Average		0.8
			Standard Deviation		0.3