Identification And Insilco Characterisation Of Differentially Expressed Aeromonas Hydrophila Induced Proteins From The Muscle Of Indian Major Carp- Gibelion Catla (Hamilton, 1822)

Abstract

Fish are significant, as they provide essential nutrients that enhance growth and health in both humans and animals. Overcrowding and environmental issues, including inadequate water quality and various stressors, can lead to disease outbreaks in farmed fish, resulting in considerable losses for farmers. Several species of Aeromonas are recognized as severe pathogenic bacteria affecting shellfish and fish. Understanding the molecular pathways influenced by A. hydrophila infection is crucial for clarifying its impacts and addressing gaps in current research. This study focused on identifying and characterizing differentially expressed proteins in the muscle of G. catla related to A. hydrophila infection. Protein measurement revealed that protein concentrations in muscle increased with infection dosage up to 500 µL/L (13.22±0.4 mg/gmFW), followed by a decline with further increase. Comparative proteome analysis via SDS-PAGE revealed that two peptides with molecular weights of 35 and 28 kDa were differentially expressed in fish exposed to A. hydrophila at dosages of 750 and 1000 µL/L. These proteins were identified as cathepsin and mitochondrial NADH dehydrogenase subunit 2. The physicochemical characterization revealed that the cathepsin and mt NADH dhf-2 proteins were acidic, with pI values of 5.58 and 5.70. The secondary structure indicated that random coils and alpha helices were predominant in cathepsin and mt NADH dhf-2, with respective percentages of 52.40% and 45.90%. Additionally, homology modeling revealed that C8he9A and C5xtbN are the most appropriate templates for cathepsin and mt NADH dhf-2. This research demonstrated that the predicted 3D models of cathepsin and mt NADH dhf-2 were reliable and coherent.