Discovery and Characterization of MaK: A Novel Knottin Antimicrobial Peptide from Monochamus alternatus.

Knottin-type antimicrobial peptides possess exceptional attributes, such as high efficacy, low vulnerability to drug resistance, minimal toxicity, and precise targeting of drug sites. These peptides play a crucial role in the innate immunity of insects, offering protection against bacteria, fungi, and parasites. Knottins have garnered considerable interest as promising contenders for drug development due to their ability to bridge the gap between small molecules and protein-based biopharmaceuticals, effectively addressing the therapeutic limitations of both modalities. This work presents the isolation and identification of a novel antimicrobial peptide derived from Monochamus alternatus. The cDNA encodes a 56-amino acid knottin propeptide, while the mature peptide comprises only 34 amino acids. We have labeled this knottin peptide as MaK. Using chemically synthesized MaK, we evaluated its hemolytic activity, thermal stability, antibacterial properties, and efficacy against nematodes. The results of this study indicate that MaK is an exceptionally effective knottin-type peptide. It demonstrates low toxicity, superior stability, potent antibacterial activity, and the ability to suppress pine wood nematodes. Consequently, these findings suggest that MaK has potential use in developing innovative therapeutic agents to prevent and manage pine wilt disease.

The complete mitochondrial genome of Arhopalus oberthuri Hua, 2002 (Coleoptera: Spondylidinae).

Arhopalus oberthuri is a pest which spreads in China, Laos, Japan and some other countries in Asia. The complete mitochondrial genome of A. oberthuri is 15,854 bp in length with 32.1% GC content, including 38.2% A, 20.4% C, 11.7% G, 29.7% T. There are 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNA) and two ribosomal RNA genes (rRNA) encoded in the genome. The graph of phylogenetic analysis gives the information that Arhopalus oberthuri is closer to Arhopalus unicolor. This study provided a scientific basis for the population genetics, phylogeny, and molecular taxonomy of A. oberthuri.

The complete mitochondrial genome of Trictenotoma davidi Deyrolle, 1875 (Coleoptera: Trictenotomidae).

Trictenotoma davidi Deyrolle, 1875 is a beetle of the Trictenotomidae family. The length of the complete mitochondria genome of T. davidi was 15,910 bp with 24.1% GC content, including 39.9% A, 15.1% C, 9.0% G, and 36.0% T. The genome encoded 13 protein-coding genes, 22 tRNAs, and 2 rRNAs. Phylogenetic analysis showed that T. davidi was closely related to Vincenzellus ruficollis. This study provided useful genetic information for the evolution of T. davidi and Trictenotomidae insects.