Table 1.

Physicochemical parameters of SARS-CoV-2 3CLpro and avian 3CLpro of avian infectious bronchitis virus.

Parameters	SARS-CoV-2 3CLpro	Avian 3CLpro (Infectious bronchitis virus)
Mol. Weight	33,462.96	39,229.60
No. of amino acids	307	355
Theoretical pI	5.95	6.35
Instability index (II)	27.65	41.98
No. of Negatively Charged Residues (Asp + Glu)	26	31
No. of Positively Charged Residues (Arg + Lys)	22	29
Aliphatic Index	82.12	88.93
Grand average of Hydropathicity (GRAVY)	− 0.019	0.007
Atomic Composition	Carbon-1499; Hydrogen-2318; Nitrogen-402; Oxygen-445; Sulfur-22	Carbon-1502; Hydrogen-2323; Nitrogen-397; Oxygen-450; Sulfur-10
Amino Acid Composition	Ala-17 (5.6%); Arg-11 (3.6%); Asn-21(6.9%); Asp-17(5.6%); Cys-12 (3.9%); Gln-14 (4.6%); Glu-9 (2.9%); Gly-26; (8.5%); His-7 (2.3%); Ile-11 (3.6%); Leu-29 (9.5%); Lys-11 (3.6%); Met-10 (3.3%); Phe-17 (5.6%); Pro-13 (4.2%); Ser-16 (5.2%); Thr-24 (7.8%); Trp-3 (1.0%); Tyr 11(3.6%); Val-27 (8.8%)	Ala-25 (7%); Arg-14 (3.9%); Asn-23 (6.5%); Asp-12 (3.4%); Cys-9 (2.5%); Gln-9 (2.5%); Glu-19 (5.4%); Gly-28 (7.9%); His-6 (1.7%); Ile-22 (6.2%); Leu-28 (7.9%); Lys-15 (4.2%); Met- 4 (1.1%); Phe-16 (4.5%); Pro-13 (3.7%); Ser-31(8.7%); Thr-24 (6.8%); Trp-6 (1.7%); Tyr-11 (3.1%); Val-33 (9.3%); Pyl-3 (0.8%); Sec-2 (0.6%)