New version of an anti-bacterial protein from the swimming crab: gene, where it’s active, and its infection-fighting ability

The full-length cDNA of a newly identified anti-lipopolysaccharide factor (PtALF5) is 1045 bp and encodes 120 amino acids.

• PtALF5 exhibits lower amino acid similarity to other anti-lipopolysaccharide factors but contains a conserved binding domain.
• The genomic structure of PtALF5 consists of two exons separated by one intron, with several tandem repeats found in the intron.
• PtALF5 mRNA is predominantly expressed in hemocytes, with minimal expression in muscle tissue.
• After exposure to the pathogen Vibrio alginolyticus, PtALF5 transcript levels in hemocytes show a time-dependent response, decreasing at 6 hours and significantly increasing at 24 hours.
• Recombinant PtALF5 protein demonstrates antimicrobial activity against Gram-negative bacteria but not against Gram-positive bacteria or fungi.

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