Fig. 8.

Classification of αHDPs and other HDP classes retrieved by the α-core signature from the UniProtKB database. Data represent results from a query of all UniProtKB sequences retrieved with the search terms: keyword [antimicrobial] + length [0–200] + organism class [Eukaryota]. Peptides manually scored for structure and type and sequences within each group are enumerated. Sequences were categorized as follows: (i) α-helical returned by the α-core formula (α-helical α-core); (ii) α-helical not returned by the α-core formula (non–α-core); (iii) linear cysteine-free sequences with many being enriched for individual amino acids (linear peptides); (iv) β-sheet defensin or defensin-like peptides (β-sheet peptides); (v) other disulfide-containing peptides (S–S peptides); (vi) Cys-stabilized peptides containing α-helix and β-sheet domains (CS−αβ); and (vii) other group including proteins with no known structure or homology to other known sequences, as well as groups that are not traditionally categorized as HDPs such as enzymes, DNA binding proteins, protease inhibitors, lectins, and toxins.