cDNA cloning and molecular characterization of a defensin-like antimicrobial peptide from larvae of Protaetia brevitarsis seulensis (Kolbe)

Abstract

We identified new defensin-like cDNA (called Psdefensin) by searching data set of high-throughput RNA sequencing (RNA-seq) expression profiling of immunized larva of white-spotted flower chafers, Protaetia brevitarsis seulensis. The length of the analyzed new defensin-like sequences were 240 base pair (bp) and encoded the deduced polypeptide of 79 amino acid residues with signal peptides (amino acids 1-20), pro-peptide region (amino acids 21-36), and mature peptide region (amino acids 37-79). The Psdefensin transcript levels were slightly up-regulated at 4 h post-infection and were highly expressed at 8 h post-infection compared to control larvae injected with sterile water. In addition, the Psdefensin did have antimicrobial activity against both Gram-negative bacteria, E. coli and Gram-positive bacteria, B. subtilis suggesting potentially pharmacologic agent.

Screening, Expression, Purification and Functional Characterization of Novel Antimicrobial Peptide Genes from Hermetia illucens (L.)

“…Several studies expressed insect AMPs in E . coli including cecropin from Plutella xylostella [45], defensin-like antifungal peptide from the whitefly Bemisia tabaci [46], and defensin-like peptides from Protaetia brevitarsis seulensis [5]. However, recombinant AMPs may affect the host viability.…”

“…In the previous report, the defensin-like antimicrobial peptide Psdefensin from Protaetia brevitarsis seulensis was cloned into pMAL expression system in an approach similar to that of this study. The purified MBP-Psdefensin proteins exhibited moderate antimicrobial activities against both Gram-negative bacteria and Gram-positive bacteria [5]. …”

“…Different AMP databases facilitate the screening, identification, and characterization of new antimicrobial peptides [4]. So far, more than 2000 AMPs from vertebrates and invertebrates have been reported according to the antimicrobial peptide database [5]. …”

“…The quick and intensive production of potent AMPs is the main factor contributing to the defense weapons generated by insects to eliminate invading pathogens rapidly [8]. Several studies have focused on identifying AMPs and antimicrobial proteins from insects [5, 9, 10]. …”

De novo genome assembly of the white-spotted flower chafer (Protaetia brevitarsis)

“…Larval stage insects have been used in traditional medicine to treat inflammatory disease, breast cancer, hepatic cancer, liver cirrhosis, and hepatitis. Furthermore, researchers have identified and characterized compounds that were associated with activity against microbial pathogens [6] and cancer cells [7, 8], as well as those that inhibited platelet aggregation or thrombosis [9]. Furthermore, P. brevitarsis larvae are also considered a good model for insect immune system studies [10–12].…”