Figure 2From: 2D-Qsar for 450 types of amino acid induction peptides with a novel substructure pair descriptor having wider scopeDefinition of a set of base substructures in SPAD, which roughly has three categories, i.e., number of atoms, substructures (above), and peptide properties (below). Number of atoms includes 'Cl', 'F', 'N', 'O', 'C', 'C in aromatic ring', 'S', 'N in aromatic ring' and 'Sum of left atoms'.Back to article page