Figure 2.

DNA and prepropeptide sequences of α4/7-CTx LvIA from C. lividus and encoded toxin (A) and its mature peptide sequence with disulfide bond connectivity Cys 1–3, Cys 2–4 (B). A) EMBL accession number of α-CTx LvIA DNA is HF566436. Putative proteolytic processing site 1 (R) and amidated processing site 2 (#G) are indicated by arrows. The intro primer is shaded. The proregion is denoted by italic lettering. The mature toxin region is underscored. The first glycine following the C-terminal cysteine in the mature toxin is presumed to be processed to a C-terminal amide for LvIA. Cysteines are indicated in boldface. Stop codons are indicated by asterisks. B) Deduced mature toxin sequence of LvIA is GCCSHPACNVDHPEIC# (where # indicates C-terminal carboxamide).