DISCERN THE PRESENCE OF A NOVEL ANTIMICROBIAL PEPTIDE (AMP) IN THE EPIDERMAL FISH MUCUS OF FRESHWATER FISH COMMON CARP Cyprinus carpio AND IDENTIFYING ITS ACTION

Thirumurugan Ramasamy*, Arun Sridhar, Sathiya Deepika,
Rajkumar Krishnasamy Sekar and Vignesh Venkatasamy
 
Laboratory of Aquabiotics/Nanoscience
Department of Animal Science
School of Life Sciences
Bharathidasan University
Tiruchirappalli-620 024
Tamil Nadu
India
ramthiru72@gmail.com; ramthiru72@bdu.ac.in

Fish are one of the organisms that are managed to survive in the presence of millions of organisms in their environment. Innate immune system serves as first line of defense to protect the host. Mucus is one of the important components of innate immunity. Mucus is secreted by epidermal goblet cells. It contains non-specific defense factors such as complement, lysozyme, interferon, C-reactive protein, haemolysin, transferrin, and lectin (haemagglutinin). The mucus acts as a barrier that prevents the access of entry of many pathogens from external surfaces. The mucus also plays roles in osmotic and ionic regulation, respiration, reproduction, and communication. These properties make the mucus as a material which has high multifunctional capacity. Antimicrobial peptides target bacterial cell membrane and cause disintegration of the lipid bilayer structure. These peptides also kill bacteria by inhibiting important pathways inside the bacterial cells such as protein synthesis and DNA replication.

The purpose of this study is to identify a novel antimicrobial peptide from the epidermal skin mucus of fish Common Carp (Cyprinus carpio). The mucus of Cyprinus carpio have been collected, pooled and extracted separately with crude, aqueous and acidic solvents. Then it was processed for protein quantification. The antimicrobial activity of the prepared mucus extract was tested against pathogenic bacteria by agar well diffusion assay. The acidic extract of mucus showed potent antimicrobial activity against the tested pathogens but no activity was observed in crude and aqueous extracts.  Based on the results, the acidic extraction, which delivered positive result, was subjected to gel filtration chromatography. Different fractions obtained were subjected to antibacterial assay. The fractions which showed the activity was identified and the protein molecular weight was observed. The results may be valuable in obtaining a new antimicrobial peptide. It could also be useful in using this antimicrobial peptide in therapeutic applications to reduce the disease related problems both in human and in aquaculture in India.