Table 1.

List of physicochemical amino acid indices and chemical groups used to derive features.

Amino acid	Code	Index	Physicochemical index/chemical groups
			MolW	pI	FH	EH	Associated chemical groups
Alanine	A	1	71.0791	6.01	0.42	0.62	CH CO NH CH3
Cysteine	C	2	103.1437	5.07	1.34	0.29	CH CO NH CH2 SH
Aspartate	D	3	115.0887	2.77	−1.05	−0.9	CH CO NH CH2 CO COO−
Glutamate	E	4	129.1157	3.22	−0.87	−0.74	CH CO NH CH2 CH2 CO COO−
Phenylalanine	F	5	147.1772	5.48	2.44	1.19	CH CO NH CH2 CAROM CHAROM CHAROM CHAROM CHAROM CHAROM
Glycine	G	6	57.0521	5.97	0	0.48	CH2 CO NH
Histidine	H	7	137.1414	7.59	0.18	−0.4	CH CO NH CH2 CAROM CHAROM N CHAROM NH
Isoleucine	I	8	113.16	6.02	2.46	1.38	CH CO NH CH2 CH CH3 CH3
Lysine	K	9	128.1792	9.74	−1.35	−1.5	CH CO NH CH2 CH2 CH2 CH2 NH3+
Leucine	L	10	113.16	5.98	2.32	1.06	CH CO NH CH2 CH CH3 CH3
Methionine	M	11	131.1977	5.47	1.68	0.64	CH CO NH CH2 CH2 S CH3
Asparagine	N	12	114.104	5.41	−0.82	−0.78	CH CO NH CH2 CO C NH2
Proline	P	13	97.1171	6.48	0.98	0.12	CHRING CO NHRING CH2RING CH2RING CH2RING
Glutamine	Q	14	128.131	5.65	−0.3	−0.85	CH CO NH CH2 CH2 CO C NH2
Arginine	R	15	156.188	10.76	−1.37	−2.53	CH CO NH CH2 CH2 CH2 NH C NH2 NH2+
Serine	S	16	87.0784	5.68	−0.05	−0.18	CH CO NH CH2 OH
Threonine	T	17	101.1054	5.87	0.35	−0.05	CH CO NH CH CH3 OH
Valine	V	18	99.133	5.97	1.66	1.08	CH CO NH CH CH3 CH3
Tryptophan	W	19	186.2139	5.89	3.07	0.81	CH CO NH CH2 CAROM CAROM CAROM NH CHAROM CHAROM CHAROM CHAROM CHAROM
Tyrosine	Y	20	163.1756	5.67	1.31	0.26	CH CO NH CH2 CAROM CHAROM CHAROM CHAROM CHAROM CAROM OH