A new isoform of anti-lipopolysaccharide factor identified from the blue swimmer crab, Portunus pelagicus: Molecular characteristics and phylogeny

作者：Afsal V V; Antony Swapna P; Sanjeevan V N; Kumar P R Anil; Singh I S Bright; Philip Rosamma^*

来源：Aquaculture, 2012, 356: 119-122.

DOI：10.1016/j.aquaculture.2012.05.028

• Antimicrobial peptide
• Portunus pelagicus
• Anti-lipopolysaccharide factor
• Crustacean immunity

Anti-lipopolysaccharide factors are small proteins that bind and neutralize lipopolysaccharide and exhibit potent antimicrobial activities. This study presents the molecular characterization and phylogenetic analysis of the first ALF isoform (Pp-ALF1; JQ745295) identified from the hemocytes of Portunus pelagicus. The full length cDNA of Pp-ALF1 consisted of 880 base pairs encoding 293 amino acids with an ORF of 123 amino acids and contains a putative signal peptide of 24 amino acids. Pp-ALF1 possessed a predicted molecular weight (MW) of 13.86 kDa and theoretical isoelectric point (pI) of 8.49. Two highly conserved cysteine residues and putative LPS binding domain were observed in Pp-ALF1. Peptide model of Pp-ALF1 consisted of two alpha-helices crowded against a four-strand beta-sheet. Comparison of amino acid sequences and neighbor joining tree showed that Pp-ALF1 has a maximum similarity (46%) to ALF present in Portunus trituberculatus followed by 39% similarity to ALF of Eriocheir sinensis and 38% similarity to ALFs of Scylla paramamosain and Scylla serrata. Pp-ALF1 is found to be a new isoform of ALF family and its characteristic similarity with other known ALFs signifies its role in protection against invading pathogens.

• 出版日期2012-8-1