An improved classification of G-protein-coupled receptors using sequence-derived features

BMC Bioinformatics

Table 6 The physicochemical properties of the amino acids and distances between two amino acids.

Order	Physicochemical property	Range of property	Reference
1	Hydrophobicity scales	[-1.14, 1.81]	[32]
2	Average flexibility indices	[0.295, 0.544]	[32]
3	Polarizability parameter	[0, 0.409]	[32]
4	Free energy of solution in water	[-2.24, 4.91]	[32]
5	Residue accessible surface area in tripeptide	[75, 255]	[32]
6	Residue volume	[36.3, 135.4]	[32]
7	Steric parameter	[0, 1.02]	[32]
8	Relative mutability	[18, 134]	[32]
9	Hydrophobicity	[-2.53, 1.38]	[33]
10	Hydrophilicity	[-3.4, 3]	[33]
11	Side-chain mass	[1, 130]	[33]
12	Normalized van der Waals volume	[0, 8.08]	[34]
13	Polarity	[4.9, 13.0]	[34]
14	Polarizability	[0, 0.409]	[34]
15	Charge	Positive, Neutral, Negative	[34]
16	Secondary structure	Helix, Strand, Coil	[34]
17	Solvent accessibility	Buried, Exposed, Intermediate	[34]
18	Relative hydrophobicity	Polar, Neutral, Hydrophobic	[34]
19	Grantham chemical distance	[0, 215]	[34]
20	Schneider-Wrede physicochemical distance	[0, 1]	[19]

ISSN: 1471-2105