Isolation and Identification of a Novel Inducible Antibacterial Peptide from the Skin Mucus of Japanese Eel, Anguilla japonica

Abstract

In this study, acetone extracts and acidic extracts were prepared from skin mucus, gill, kidney, liver and spleen of the Japanese eel, Anguilla japonica, and they exhibited different levels of antibacterial activities against three strains of Gram-negative bacteria, Edwardsiella tarda, Aeromonas hydrophila, Aeromonas sp. and one Gram-positive bacterium Micrococcus leteus. The mucus was chosen as the source of antibacterial peptide for further purification of antibacterial peptides. Following the intraperitoneal injection of A. hydrophila, one of the main pathogenic bacteria of Japanese eel and many other fish, a peptide was purified from acetic acid extraction of the skin mucus, by using cationic exchange liquid chromatography and reverse-phase high-performance liquid chromatography (RP-HPLC). The isolated antibacterial peptide, named as AJN-10, exhibited antibacterial activity against A. hydrophila. The AJN-10 is a heat-tolerant and hydrophilic peptide. The molecular weight of this peptide is 6,044.28 Da, as determined by matrix-assisted laser desorption ionisation time of flight mass spectrometry. The 20 N-terminal amino acid sequences were clarified by Edman degradation, and based on results of homology search by BLAST analysis of the 20 N-terminal sequences, the AJN-10 showed little similarity to other proteins in databases.

Evaluation of antibacterial activity and innate immune components in skin mucus of Indian major carp,Cirrhinus mrigala

“…Nevertheless, this observation is in contradiction with their previous report (Subramanian et al 2007), and it was stated by them (Subramanian et al 2008) that the absence of antibacterial activity in the aqueous extracts could be due to the inactivation of the enzymes by temperature and/or pH conditions used at the time of incubation during the antimicrobial assay. Birkemo et al (2003), Subramanian et al (2009) andLiang et al (2011) also performed AA extraction of skin mucus of Hippoglossus hippoglossus, M. glutinosa and A. japonica, respectively, to isolate and purify antibacterial peptides. Palaksha, Shin, Kim and Jung (2008) reported antibacterial activity in the aqueous extract of the skin mucus of Paralichthys olivaceus against several bacterial strains.…”

“…Hellio, Pons, Beaupoil, Bourgougnon and Le Gal (2002) and Subramanian, Ross and MacKinnon (2008) compared antibacterial activities in the epidermal mucus extracts of several fish species from the North Atlantic. Histone H2A, and chromosomal protein-derived oncorhyncins I, II, III from Oncorhynchus mykiss (Fernandes, Kemp, Molle & Smith 2002;Fernandes, Saint, Kemp & Smith 2003;Fernandes, Molle, Kemp & Smith 2004), histone H2B and various ribosomal proteins from Gadus morhua (Bergsson, Agerberth, Jornvall & Gudmundsson 2005), myxinidin from Myxine glutinosa (Subramanian, Ross & MacKinnon 2009), pelteobagrin from Pelteobagrus fulvidraco (Su 2011) and AJN-10 from Anguilla japonica (Liang, Guan, Huang & Xu 2011) have been purified and found potent antibacterial agents acting as a defence component over the body of fish. Many of the fish antimicrobial peptides have high sequence homology to segments of other proteins (particularly histone or histone-like molecules) indicating that they may in fact be cleavage products of larger molecules.…”

Antibacterial Activity of Eel (Anguilla spp.) Mucus against Salmonella typhi

“…(4)(5)(6) Although the antibacterial activity of Anguilla spp. against various pathogens has been reported earlier, very little is known about its activity against S. typhi.…”

Isolation and characterization of a novel antibacterial peptide derived from hemoglobin alpha in the liver of Japanese eel, Anguilla japonica

“…An AMP, Parasin I has been identified in skin mucus of Japanese eel [12]. We have previously identified an AMP, named as AJN-10, and characterized partially, which exhibited antibacterial activity against Aeromonas hydrophila, but its amino acid sequence was not determined [13]. Moreover, only a 45 kDa glycoprotein was identified in skin mucus of other eels, i.e.…”