In this section, four protein encoding schemes based on PSSM are introduced for a comparison. They are the average score of the residues with respect to the column of certain AA type called AvePscore-20 [21], the average score of the residues of certain AA type with respect to the column of certain AA type called AvePscore-400 [74], the percentile value of the PSSM scores along with the column of certain AA type according to percent thresholds called Pscore-100 [75], and auto-correlation coefficient (ACC) transformation that can transform the PSSMs of different lengths into fixed-length vectors by measuring the correlation between two scores separated by a distance of lg along the sequence [76], respectively. Table 2 lists the predictive results of the proposed protein representation and other four considered protein representations on the benchmark dataset using jackknife validation.