1. Purification and molecular cloning of cDNA for an inducible antibacterial protein from larvae of the coleopteran, Tenebrio molitor
H J Moon, S Y Lee, S Kurata, S Natori, B L Lee J Biochem. 1994 Jul;116(1):53-8. doi: 10.1093/oxfordjournals.jbchem.a124502.
Antibacterial activity was induced in the hemolymph of larvae of the coleopteran Tenebrio molitor by injection of Escherichia coli. An antibacterial protein, named tenecin 1, was purified to homogeneity from the larval hemolymph and characterized. A cDNA clone for tenecin 1 was isolated and its complete sequence was determined. This protein was found to inhibit the growth of Gram-positive bacteria and to consist of 43-amino acid residues including six cysteine residues. The disulfide structure of tenecin 1 was determined by sequencing cysteine containing peptides obtained by digesting tenecin 1 with endopeptidase Lys-C, trypsin, and thermolysin. The amino acid sequence and its disulfide bonds were similar to those of sapecin and sapecin C, antibacterial proteins of Sarcophaga peregrina.
2. Purification, sequence and antibacterial activity of two novel sapecin homologues from Sarcophaga embryonic cells: similarity of sapecin B to charybdotoxin
K Yamada, S Natori Biochem J. 1993 Apr 1;291 ( Pt 1)(Pt 1):275-9. doi: 10.1042/bj2910275.
Two sapecin homologues were purified from the culture medium of NIH-Sape-4, an embryonic cell line of Sarcophaga peregrina (flesh fly). These homologues contained six cysteine residues with exactly the same disulphide pairings as those in sapecin. The amino acid sequence of one of them, sapecin C, was also very similar to that of sapecin. The other homologue, sapecin B, was less similar to sapecin but showed significant similarity to charybdotoxin, an inhibitor of K+ channels isolated from a scorpion venom. Like sapecin, these homologues repressed the growth of various Gram-positive bacteria.
