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Characterization of a Novel Antimicrobial Peptide, Riptocin, from a Hemimetabolous Insect, Riptortus pedestris
- 언어ENG
- URLhttps://db.koreascholar.com/Article/Detail/287523
Biological properties of antimicrobial peptides (AMPs) of hemimetabolous insect are poorly characterized in innate immunity field. To investigate the biochemical properties of hemimetabolous insect’s AMPs, we purified the pyrrhocoricin-like AMP from the hemolymph of Riptortus pedestris and then named as riptocin. We successfully determined the primary protein structure and its cDNA sequence. Interestingly, the determined cDNA revealed that riptocin precursor is composed of 12 repeating units of active riptocins, which implied that riptocin precursor might require to be processed to generate active riptocins by several unidentified processing enzymes. In order to characterize the bio-processing mechanisms of riptocin precursor, we generated the antibody against active riptocin. Using quantitative PCR and Western blot analyses, we showed that gene of riptocin was started to express from the fatbody after three hours post bacterial infection. To address our hypothesis that active riptocin is generated from riptocin precursor by several processing enzymes, we need to obtain the riptocin precursor. Currently, we are expressing the recombinant riptocin precursor using in vitro translation system. Meanwhile, we investigated whether naive hemolymph (naive HL), which may contain precursor riptocin, can generate active riptocin when riptocin precursor was co-incubation with bacteria-challenged hemolymph (active HL), which may contain all processing enzymes. Actually, when naive HL was incubated with active HL, antimicrobial activity was dramatically increased, suggesting that processing enzymes in active HL may induce processing of riptocin precursor to generate active riptocins.
