Table 5.

Stable intermolecular hydrogen bond pairs observed in the structures selected for sG and sC states from the MD simulations for the Siglec-3 (I56R) – 6’-sulfo-sLacNAc, Siglec-3 (I56R) – 6-sulfo-sLacNAc, and Siglec-3 (I56R) – 6’,6-disulfo-sLacNAc complexes.

Ligand – Atom		Protein – Atom	Siglec-3 (I56R) – 6’-sulfo-sLacNAc		Siglec-3 (I56R) – 6’,6-disulfo-sLacNAc		Siglec-3 (I56R) – 6-sulfo-sLacNAc
			sG state	sC state	sG state	sC state	sG state	sC state
Neu5Ac	O1a	R109, Nη1	2.9 ± 0.2 (100)b, c, d	2.9 ± 0.3 (100)d	2.9 ± 0.2 (100)d	2.9 ± 0.3 (100)d	2.9 ± 0.2 (100)d	2.9 ± 0.2 (100)d
		R109, Nη2	3.0 ± 0.2 (100)d	3.0 ± 0.2 (100)d	3.0 ± 0.2 (100)d	3.0 ± 0.2 (100)d	3.0 ± 0.2 (100)d	3.0 ± 0.2 (100)d
	N5	K116, O	2.9 ± 0.2 (83)	2.9 ± 0.1 (92)	2.9 ± 0.2 (87)	2.9 ± 0.2 [97]	3.0 ± 0.2 (68)	2.9 ± 0.2 (84)
	O9	S118, O	2.9 ± 0.2 (14)	2.9 ± 0.2 (57)	2.9 ± 0.2 (17)	2.9 ± 0.2 (42)	2.9 ± 0.2 (25)	2.9 ± 0.2 (27)
6’-sulfo	O	R56, Nε	3.0 ± 0.2 (26)	3.0 ± 0.2 (26)	3.0 ± 0.2 (37)	3.0 ± 0.2 (68)	--e	--
		R56, Nη2	3.0 ± 0.2 (21)	3.0 ± 0.2 (22)	3.0 ± 0.2 (23)	2.9 ± 0.2 (51)	--	--
		S58, Oγ	2.7 ± 0.2 (35)	2.8 ± 0.2 [96]	2.7 ± 0.2 (41)	2.8 ± 0.2 (91)	--	--
6-sulfo	O	R56, Nε	--	--	--	--	--	3.0 ± 0.2 (24)
		R56, Nη2	--	--	--	--	--	2.9 ± 0.2 (18)
		S58, Oγ	--	--	--	--	--	2.7 ± 0.2 (46)
		K120, Nζ	--	--	--	2.9 ± 0.2 (49)	--	2.9 ± 0.2 (12)

^awhen multiple hydrogen bonds are formed between multiple equivalent heavy atoms, the occupancy of the interaction listed is the sum of all the individual hydrogen bonds and the distance is the average of all the individual hydrogen bonds.

^bdistance in Å.

^cpercentage (%) based on a distance between non-hydrogen atoms of less than 3.5 Å.

^dthe occupancy of the interactions between multiple equivalent heavy atoms, calculated as the sum of all the individual hydrogen bonds, is greater than 100%.

^eno stable interactions observed.