Regarding the types of structures reported in the set of peptides analyzed (Figure ), the predominant structure (34%) in them is the alpha helix. The primary method used to elucidate the structure of anti-MRSA peptides with known structures was nuclear magnetic resonance (23 / 14% -Figure -C in the Supplementary material). Also remarkable is that a representative portion of the structures (41 / 25%) of the peptides studied herein are predicted computationally, and more than half of the peptidic structures of this data set have not been associated with any experimental or predicted structure (94 / 57%). Sequence alignment of the peptide pairs 1 -5 (Figure ) confirms that these pairs of peptides have comparable amino acid sequences (from 0.13 to 0.61). However, the distance calculated based on their peptide chemical structure does not necessarily have a linear relationship with the identity of peptide sequences (Figure ). This observation suggests that the MAP4 fingerprints are helpful to compare the chemical structures of the peptides in addition to the AA sequence. Nevertheless, the 2D and 3D alignments of AA typically used in bioinformatics provides additional and intuitive information to decode the P-SPRs. For example, peptide pair 1 (Figure ) shows a low fingerprint-based similarity (0.131) in contrast with their sequence-based identity (100%). This data suggests that the fingerprint-based similarity could be highly sensitive to small structural changes in short peptides (< 20 AA). In contrast, the peptide pairs 2 -5 exhibit good relationships between their fingerprint-based similarity and their sequence-based identity (0.43 vs. 69%; 0.55 vs. 55%; 0.57 vs. 57%; 0.61 vs. 52%, respectively). This suggests that our fingerprint-based similarity metric could be useful to quantify the similarity between medium-large peptides (> 20 AA).