TABLE 1.

Mass-based identification of VHSV G protein peptides^a

Peptide	Amino acids	Cys position	MMmeas (Da)	MMcalc (Da)
L1c	1–53	C29, C44	6,711.5	6,712.3
			7,002.2	7,003.6
			7,293.4	7,294.8
L2	54–61		798.8	800.0
L3	62–102	C90	4,518.2	4,521.2
L4	103–108		674.5	673.8
L5	109–120		1,335.1	1,334.4
L6	121–136	C132	2,083.6	2,083.4
L7–L9b	137–151		1,859.0	1,858.1
L10	152–161		1,167.4	1,167.3
L11e	162–192	C172, C177	3,478.5	3,480.9
L11	162–192		3,692.2	3,693.2
L12	193–216	C195	2,828.4	2,829.2
L13e	217–242	C231, C236	2,797.3	2,798.3
L13f	217–242		3,010.0	3,010.6
L14	243–259		1,628.8	1,628.8
L15–L16b	260–264		586.3	585.7
L17	265–307	C265, C295	4,826.6	4,828.3
L18	308–315		894.0	894.1
L19	316–325		1,079.7	1,079.2
L20	326–355	C339	3,494.3	3,493.9
L21	356–362		n.o.g	861.5
L22	363–365		n.o.	419.5
L23–L24b	366–390		2,856.9d	2,839.2
L25	391–466		n.o.	8,640.9
L26	467–487		n.o.	2,318.6

^aComparison of MM_meas and MM_calc for the peptides generated by an endoproteinase LysC digestion of PNGase F-treated, reduced, and iodoacetamide-alkylated G protein (digest A). 

^bTwo or more peptides were connected due to lack of cleavage. 

^cAn O-linked glycan was identified; masses corresponding to 0, 1, or 2 sialic acids are given. 

^dA methione residue in the peptide was presumably oxidized, as the mass appears 16 Da higher than the theoretical mass. 

^eAn intrapeptide disulfide bond was not reduced or alkylated under the initial experimental conditions. 

^fAdditional treatment with DTT and 4-VP (as described in text) resulted in the reduction and alkylation of the bond. 

^gn.o., not observed.