Figure 6. Homology model of HCa.

Backbone ribbon representation of the model of HCa and comparison with the structure of MCa (PDB code 1C6W [11]), which, besides IpTx A, is one of the two structures used as template for molecular modelling. Disulfide bridges are in stick representation. Basic amino acid residues present on the same face of MCa and HCa (Lys¹⁹, Lys²⁰, Lys²², Arg²³, Arg²⁴ and Lys³⁰) are shown. The side-chain bonds of Lys¹¹, Lys¹⁴, Asp¹³ and Ala¹² in HCa and Lys¹¹, Lys¹⁴, Asn¹³ and Glu¹² in MCa are also shown.