Descriptors of VSTV for 20 coded amino acids.
AA	Abbr.	VSTV1 a	VSTV2	VSTV3
Ala	A	-1.33	0.41	-0.10
Arg	R	1.22	-0.55	2.31
Asn	N	-0.20	1.05	0.61
Asp	D	-0.21	1.34	0.64
Cys	C	-1.02	-0.32	-0.69
Gln	Q	0.20	0.41	1.02
Glu	E	0.18	0.71	1.04
Gly	G	-1.66	0.78	0.24
His	H	0.61	0.93	-0.80
Ile	I	-0.12	-1.27	-0.38
Leu	L	-0.17	-1.24	-0.02
Lys	K	0.39	-1.42	1.46
Met	M	-0.24	-2.48	-0.28
Phe	F	1.07	0.10	-0.36
Pro	P	-0.54	-0.33	-1.73
Ser	S	-0.94	0.90	0.03
Thr	T	-0.58	0.51	-0.30
Trp	W	2.42	0.49	-1.87
Tyr	Y	1.51	0.56	-0.11
Val	V	-0.58	-0.57	-0.71
a The 3 principal component scores as VSTV descriptors are derived from PCA on a matrix of 25 structural and topological variables of 20 coded amino acids.
References [1] H. Mei, Y. Zhou, L. L. Sun, Z. L. Li, A new descriptor of amino acids and its application in peptide QSAR, Acta Phys.-Chim. Sin., 20 (2004) 821-825.