Sulphated polysaccharides from seaweeds as potential entry inhibitors and vaccine adjuvants against SARS-CoV-2 RBD spike protein: a computational approach

Figures & data

Table 1. Docking score results for SARS–CoV-2 receptors binding with the potential inhibitors.

No	Ligand name	Binding energies (ΔG) Kcal/mol	Types of interactions
1	Sulphated Galactan (G)	−5.3	5 H-bonding with LYS 357, ARG 466, ARG 355 4 π – Sulphur with, TYR 396, ARG 466, ARG 355
2	Pyranosic arabinan (G)	−5.7	9 H-bonding with GLN 498, ASN 501, GLY 496, GLN 493, TYR 453 1 π – Sulphur with, TYR 449
3	Rhamnan sulphate (G)	−5.2	3 H-bonding with MET 430, PHE 515, 1 Carbon Hydrogen bond with ASP 428
4	Ulvanobiose (G)	−5.3	5 H-bonding with SER 349, TYR 351, ASN 450, LYS 452 1 Carbon Hydrogen bond with PRO 348
5	Sulphated fucoidan (B)	−6.9	8 H-bonding with PHE 347, SER 349, TYR 351, ASN 450, TYR 451, LYS 452, ARG 509 2 π – Donor Hydrogen-bonds with LYS 346, PRO 348, TYR 451
6	Sulphated homogeneous Galactan (B)	−5.9	4 H-bonding with PHE 347, ASN 450, ASN 448, SER 349
7	Sulphated fucose (B)	−5.1	6 H-bonding with PHE 347, SER 349, ASN 448, ASN 450 1 π – Sulphur with, TYR 351
8	Sulphated Galactofucan (B)	−6.3	5 H-bonding with PHE 347, SER 349, LYS 452, ARG 509 1 π – Sulphur with PHE 464
9	Sulphated fucan (B)	−6.0	2 H-bonding with TYR 396, GLU 516 3 π – Sulphur with TYR 351, LYS 452, ARG 509 1 Carbon Hydrogen bond with LYS 346
10	Porphyran (R)	−5.0	6H-bonding with ASN 437, AGR 439, ASN 440 1 Carbon Hydrogen bond with THR 372
11	κ_carrageenan (R)	−6.5	2 H-bonding with ASN 450 2 Carbon Hydrogen bonds with PRO 348, ILE 441
12	λ_carrageenan (R)	−5.8	8 H-bonding with PHE 373, ASN 437, ARG 439, GLN 506 1 Carbon Hydrogen bond with ASN 437
13	ι_ carrageenan (R)	−6.3	3 H-bonding with TYR 449, ASN 450 1 Carbon Hydrogen bond with ILE 441
14	Poligeenan (R)	−6.2	3 H-bonding with LYS 403, GLN 493
15	Xylan sulphate (R)	−8.2	3 H-bonding with ASP 428, MET 430 4 π – Sulphur with ARG 355, ASP 428, PHE 464, GLU 516 1 π – π shaped with PHE 464
16	Heparin tetrasaccharide N-sulphated (R)	−7.3	5 H-bonding with ARG 355, LYS 356, LYS 462 1 π – Alkyl bond with LYS 356
17	Heparin(R)	−7.0	10 H-bonding with PHE 342, ASN 343, ALA 344, TYR 345, PHE 374, TRP 436, ARG 439, ASN 440, GLN 506, ARG 509 2 π – Sulphur with PHE 373, TRP 436 2 Carbon Hydrogen bonds with, ASN 343, ASN 437

(G): green; (B): Brown; (R): Red seaweeds.

Figure 1. The hydrophobic surface of protein receptor interactions with Haparin (A) and Xylan sulphate (B), from blue for hydrophilic to brown for hydrophobic.