Title : Characterization of Antimicrobial Properties of Troh2a-29 Peptide from Golden Pompano (Trachinotus Ovatus)
Abstract:
Antimicrobial peptides (AMPs) are small, potent molecules that serve as a crucial first line of defense across a wide range of organisms, including fish. In this study, we investigated the antimicrobial properties of a novel peptide, spanning residues 52 to 80 of the full-length histone H2A protein, comprising a total of 29 amino acids. This peptide, designated as Histone H2A-29 (TroH2A-29), was derived from the golden pompano (Trachinotus ovatus) and evaluated for its activity against both Gram-positive bacteria, Lactococcus garvieae and Staphylococcus epidermidis, and Gram-negative bacteria, Vibrio alginolyticus and Vibrio harveyi. Quantitative real-time PCR (qRT-PCR) analysis revealed upregulation of TroH2A expression in response to infections by L. garvieae and V. harveyi. Structural predictions, including a helical wheel plot and 3D modeling, indicated that TroH2A-29 possesses characteristic features of AMPs. Notably, TroH2A-29 induced significant agglutination of all four bacterial species in the presence of Ca2+. However, antimicrobial activity was observed against L. garvieae, V. harveyi, and V. alginolyticus, but not against S. epidermidis. Transmission electron microscopy (TEM) and propidium iodide (PI) staining confirmed the presence of abnormal morphological changes and damage in the bacterial cells treated with TroH2A-29, except in S. epidermidis, where no significant structural alterations were observed. Additionally, TroH2A-29 caused membrane depolarization in all tested bacterial strains. In conclusion, TroH2A-29 demonstrated potent antimicrobial activity against L. garvieae, V. harveyi, and V. alginolyticus, but not against S. epidermidis. These findings highlight the potential of TroH2A-29 as a novel antimicrobial peptide with selective bactericidal properties.
Keywords: Antimicrobial peptide, Histone H2A-29, Golden Pompano
