Table 1. List of descriptors.

Type	Abbreviation	Description	N
Global	NetCharge@5	Net charge at pH = 5.	1
	NetCharge@7	Net charge at pH = 7.	1
	NetCharge@9	Net charge at pH = 9.	1
	pI	Isoelectric point.	1
	AA Count	Total amino acid count.	1
	chPos	Sum and average of positive charges in side chain.	2
	chNeg	Sum and average of negative charges in side chain.	2
	Zi Average	Z-scale average sum along peptide sequence.	5
	μZi	Z-scale moment distribution along peptide sequence.	5
Topological	AC	Min and Max auto covariance values between the same descriptor.	100
	CC	Min and Max cross covariance values between two descriptors.	400

Two classes of descriptor were used in order to describe a single amino acidic sequence: global descriptors and topological descriptors. Here are listed for each class the type and number of variables.