Table II. The PAI is the ratio between the total number of spectra obtained during the protein identification process on the theoretical number of peptides ranging between 800 to 2,500 D and detectable by mass spectrometry for a given protein.

Three technical repetitions were performed for each coimmunoprecipitation (three LC-MS/MS analyses of the peptides extracted from each 120-kD band [X!Tandem pipeline parser 3.2]). IP, Immunoprecipitation. Italic entries represent the ratio of the PAI of the IP-targeted isoform on the PAI of the less represented isoform.

CESA	Coverage	Mass	PAI
			Anti-CESA1					Anti-CESA3					Anti-CESA6
			IP1-1	IP1-2	IP1-3	Mean	Ratio	IP3-1	IP3-2	IP3-3	Mean	Ratio	IP6-1	IP6-2	IP6-3	Mean	Ratio
	%	kD
CESA1	25	122.0	0.610	0.317	0.366	0.431	1.872	0.439	0.220	0.171	0.276	1.009	0.366	0.220	0.293	0.293	1.000
CESA3	38	119.5	0.262	0.190	0.238	0.230	1.000	0.667	0.667	0.452	0.595	2.172	0.500	0.190	0.286	0.325	1.112
CESA6	30	122.3	0.289	0.178	0.267	0.244	1.062	0.333	0.289	0.200	0.274	1.000	1.000	0.378	0.578	0.652	2.227