Table 2. Regions Containing Arginine or Citrulline Detected Using Liquid Chromatography–Mass Spectrometry/Mass Spectrometry^a.

	experiment 1				experiment 2						experiment 3			experiment 4
	(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)	(11)	(12)	(13)	(14)
Arg131	N	√	√	√	N	N	N	N	N	N	N	√	N	√
Arg314	√	N	N	√	N	N	N	N	N	N	N	N	×	N
Arg343	×	N	N	√	×	×	×	×	×	×	×	√	×	√
Arg346	×	N	N	√	×	×	×	×	×	×	×	×	×	×
Arg372	×	×	×	√	×	×	×	×	×	×	×	×	×	×
Arg394	×	√	√	×	×	×	×	×	×	×	×	×	×	×
Arg397	N	√	√	N	N	N	N	N	N	N	N	N	N	N
Arg399	N	√	√	√	N	N	N	N	N	N	N	√	×	√
Arg427	N	N	N	N	N	N	N	N	N	N	√	N	√	√
Arg447	N	N	√	N	N	N	N	N	N	N	N	N	N	N
Arg510	N	√	√	√	N	N	N	N	N	N	N	N	N	N

^a√, the identified citrullinated arginine moiety; ×, the noncitrullinated arginine site identified; N, the arginine site not detected in the experiment. The experiments were conducted four times. The L. O. T. of WT PAD3 samples are different from each other. However, for the third and fourth measurements, the L. O. T. of WT PAD3 samples were identical (see Table 1).