Table 2. Summary of ESI-MS data for 2-aminopyridylaminated glycans from Ascaris suum.

Proposed compositions, the predominant charged species, theoretical and observed m/z as well as sensitivity to combined fucosidase and galactosidase (‘glycosidase’) digestion, galactosidase digestion alone and the results of the HF treatment are shown. Due to in-source fragmentation, there is an inherent bias towards smaller species, which in part will not be naturally present on Ascaris glycoproteins.

Glycan composition	[M+H]⁺ calc.	Predominant ion	m/z theoretical	m/z found	Glycosidase sensitive	Galactosidase sensitive	HF sensitive
Oligomannosidic and paucimannosidic structures
HexNAc₂Hex₁	665.2846	[M+H]⁺	665.2846	665.3309
HexNAc₂Hex₁Fuc₁	811.3424	[M+H]⁺	811.3424	811.3931
HexNAc₂Hex₂	827.3373	[M+H]⁺	827.3373	827.3730
HexNAc₂Hex₂Fuc₁	973.3952	[M+H]⁺	973.3952	973.4291
HexNAc₂Hex₃	989.3901	[M+H]⁺	989.3901	989.4585	^*
HexNAc₂Hex₂Fuc₂	1119.4531	[M+H]⁺	1119.4531	1119.5190	Yes		Yes
HexNAc₂Hex₃Fuc₁	1135.4481	[M+H]⁺	1135.4481	1135.4785	^*
HexNAc₂Hex₄	1151.4429	[M+H]⁺	1151.4429	1151.4956
HexNAc₂Hex₃Fuc₂	1281.5059	[M+H]⁺	1281.5017	1281.5914	Yes		Yes
HexNAc₂Hex₄Fuc₁	1297.5008	[M+H]⁺	1297.5008	1297.5881	Yes
HexNAc₂Hex₅	1313.4957	[M+H]⁺	1313.4957	1313.5510
HexNAc₂Hex₆	1475.5485	[M+2H]²⁺	738.2779	738.3330
HexNAc₂Hex₇	1637.6014	[M+2H]²⁺	819.3044	819.3519
HexNAc₂Hex₈	1799.6541	[M+2H]²⁺	900.3307	900.3765
HexNAc₂Hex₉	1961.7070	[M+2H]²⁺	981.3572	981.4147
HexNAc₂Hex₁₀	2123.7597	[M+2H]²⁺	1062.3835	1062.4513
HexNAc₂Hex₁₁	2285.8125	[M+2H]²⁺	1143.4099	1143.5077
Complex and hybrid structures
HexNAc₃Hex₃	1192.4696	[M+H]⁺	1192.4696	1192.5438
HexNAc₃Hex₃Fuc₁	1338.5274	[M+2H]²⁺	669.7673	669.8187	Yes
HexNAc₄Hex₃	1395.5489	[M+2H]²⁺	698.2781	698.2921
HexNAc₃Hex₃Fuc₂	1484.5853	[M+2H]²⁺	742.7963	742.8596	Yes		Yes
HexNAc₄Hex₃Fuc₁	1541.6069	[M+2H]²⁺	771.3071	771.3533	Yes
HexNAc₄Hex₄	1557.6018	[M+2H]²⁺	779.3045	779.3304	Yes	Yes
HexNAc₄Hex₄Fuc₁	1703.6596	[M+2H]²⁺	852.3334	852.3865	Yes	Yes
HexNAc₅Hex₃	1598.6284	[M+2H]²⁺	799.8178	799.8515
HexNAc₃Hex₄Fuc₂	1646.6381	[M+2H]²⁺	823.8227	823.8736		Yes	Yes
HexNAc₃Hex₅Fuc₁	1662.6330	[M+2H]²⁺	831.8202	831.8696	Yes
HexNAc₄Hex₃Fuc₂	1687.6647	[M+2H]²⁺	844.3360	844.3635	Yes		Yes
HexNAc₄Hex₅	1719.6545	[M+2H]²⁺	860.3309	860.3995	Yes	Yes
HexNAc₅Hex₃Fuc₁	1744.6862	[M+2H]²⁺	872.8467	872.9117	Yes
HexNAc₄Hex₅Fuc₁	1865.7125	[M+2H]²⁺	933.3599	933.4164	Yes	Yes
PC-containing structures
HexNAc₃Hex₃PC₁	1357.5251	[M+2H]²⁺	679.2662	679.3078			Yes
HexNAc₃Hex₃Fuc₁PC₁	1503.5829	[M+2H]²⁺	752.2951	752.3353	Yes		Yes
HexNAc₄Hex₃PC₁	1560.6044	[M+2H]²⁺	780.8058	780.8600			Yes
HexNAc₃Hex₅PC₁	1681.6306	[M+2H]²	841.3189	841.3498			Yes
HexNAc₄Hex₃Fuc₁PC₁	1706.6624	[M+2H]²⁺	853.8365	853.8905	Yes		Yes
HexNAc₄Hex₃PC₂	1725.6599	[M+2H]²⁺	863.3336	863.3870			Yes
HexNAc₅Hex₃PC₁	1763.6839	[M+2H]²⁺	882.3456	882.4037			Yes
HexNAc₄Hex₄Fuc₁PC₁	1868.7151	[M+2H]²⁺	934.8612	934.9277	Yes	Yes	Yes
HexNAc₅Hex₃Fuc₁PC₁	1909.7417	[M+2H]²⁺	955.3745	955.4325	Yes		Yes
HexNAc₅Hex₄PC₁	1925.7366	[M+2H]²⁺	963.3737	963.4075	Yes	Yes	Yes
HexNAc₄Hex₅Fuc₁PC₁	2030.768	[M+2H]²⁺	1015.8876	1015.9613	Yes	Yes	Yes

The intensity of the HexNAc₂Hex₃Fuc₁ peak was reduced, but not abolished, after combined galactosidase/fucosidase digestion, because HexNAc₂Hex₃Fuc₂ is digested to HexNAc₂Hex₃Fuc₁, whereas the HexNAc₂Hex₃Fuc₁ is in turn digested to HexNAc₂Hex₃, the intensity of which is concomitantly increased.