. 2015 Apr 27;10(4):e0124784. doi: 10.1371/journal.pone.0124784

Table 1. Summary of O-glycosylation of secreted gp120s and gp120+gp140s.

HIV-1 Sample	m/z	Charge	Calculated MW	Peptide	Carbohydrate	Approximate Intensity MS
YU2 gp120	512.9	2	1023.8	IEPLGVAPTK	Native peptide	530
	695.6	2	1389.2	IEPLGVAPTK	HexNAc.Hex	500
	841.1	2	1680.2	IEPLGVAPTK	HexNAc.Hex.NeuAc	200
	986.7	2	1971.4	IEPLGVAPTK	HexNAc.Hex.NeuAc₂	2200
	1023.7	2	2045.4	IEPLGVAPTK	HexNAc₂.Hex₂.NeuAc	480
	612.6	2	1223.2	IEPLGVAPTKAK	Native peptide	Not Observed
	940.2	2	1878.4	IEPLGVAPTKAK	HexNAc.Hex.NeuAc	Not Observed
	724.2	3	2169.6	IEPLGVAPTKAK	HexNAc.Hex.NeuAc₂	Not Observed
YU2 gp120+gp140	512.7	2	1023.4	IEPLGVAPTK	Native peptide	4940
YU2 gp120+gp140	695.2	2	1388.4	IEPLGVAPTK	HexNAc.Hex	2770
	840.7	2	1679.4	IEPLGVAPTK	HexNAc.Hex.NeuAc	500
	612.6	2	1223.2	IEPLGVAPTKAK	Native peptide	80
	940.2	2	1878.4	IEPLGVAPTKAK	HexNAc.Hex.NeuAc	100
	724.2	3	2169.6	IEPLGVAPTKAK	HexNAc.Hex.NeuAc₂	60
JRCSF gp120	512.7	2	1023.4	IEPLGVAPTK	Native peptide	2000
	695.3	2	1388.6	IEPLGVAPTK	HexNAc.Hex	1540
	840.7	2	1679.4	IEPLGVAPTK	HexNAc.Hex.NeuAc	700
	986.4	2	1970.8	IEPLGVAPTK	HexNAc.Hex.NeuAc₂	1360
	1023.4	2	2044.8	IEPLGVAPTK	HexNAc₂.Hex₂.NeuAc	230
	612.6	2	1223.2	IEPLGVAPTKAK	Native peptide	Not Observed
	940.2	2	1878.4	IEPLGVAPTKAK	HexNAc.Hex.NeuAc	340
	724.2	3	2169.6	IEPLGVAPTKAK	HexNAc.Hex.NeuAc₂	2600
NL4-3 gp120	512.7	2	1023.4	IEPLGVAPTK	Native peptide	3840
	695.2	2	1388.4	IEPLGVAPTK	HexNAc.Hex	6000
	840.6	2	1679.2	IEPLGVAPTK	HexNAc.Hex.NeuAc	4680
	986.1	2	1970.2	IEPLGVAPTK	HexNAc.Hex.NeuAc₂	180
	1023.1	2	2044.2	IEPLGVAPTK	HexNAc₂.Hex₂.NeuAc	400
	612.6	2	1223.2	IEPLGVAPTKAK	Native peptide	300
	940.2	2	1878.4	IEPLGVAPTKAK	HexNAc.Hex.NeuAc	250
	724.2	3	2169.6	IEPLGVAPTKAK	HexNAc.Hex.NeuAc₂	4100
NL4-3 gp120+gp140	512.7	2	1023.4	IEPLGVAPTK	Native peptide	3900
NL4-3 gp120+gp140	695.2	2	1388.4	IEPLGVAPTK	HexNAc.Hex	1490
	840.9	2	1679.8	IEPLGVAPTK	HexNAc.Hex.NeuAc	250
	612.6	2	1223.2	IEPLGVAPTKAK	Native peptide	370
	940.2	2	1878.4	IEPLGVAPTKAK	HexNAc.Hex.NeuAc	100
	724.2	3	2169.6	IEPLGVAPTKAK	HexNAc.Hex.NeuAc₂	Not Observed

Electrospray Nano-LC-MS/MS summary showing the O-glycan occupancy of the conserved threonine of secreted HIV-1 YU2 gp120, HIV-1 JRCSF gp120, HIV-1 NL4-3 gp120 + gp140 mixture, HIV-1 YU2 gp120 + gp140. m/z is mass to charge ratio. MW is molecular weight. HexNAc.Hex is core 1. HexNAc.Hex.NeuAc is monosialylated core1. HexNAc.Hex.NeuAc2 is disialylated core 1. HexNAc2.Hex.2NeuAc is core 2.