IDENTIFICATION AND CHARACTERIZATION OF DIGESTIVE ENZYMES IN BLACK FLOUNDER USING BIOINFORMATIC TOOLS

ARMANI TOMAS; FERNANDO VILLARREAL; MECHALY ALEJANDRO

Mar del Plata

Congreso; REUNIÓN CONJUNTA SAIC, SAB, AAFE y AACYTAL 2023; 2023

SAIC, SAB, AAFE y AACYTAL

Black flounder, Paralichthys orbignyanus, is a flatfish found in the coastal waters of Argentina, Brazil, and Uruguay and is an important regional fishery resource. Despite its potential for aquaculture, one of the obstacles to its large-scale commercial farming in South America is the lack of nutritionally suitable pellets for this carnivorous fish. Understanding digestive enzymes is critical because they play a central role in nutrient processing, particularly carbohydrate and protein digestion. Studying the key digestive enzymes of P. orbignyanus could lead to improved feed design that increases nutritional value and sustainably reduces waste. Therefore, integrating different bioinformatics approaches together with phylogenetic and comparative genomic analyzes can be of great help in studying the physiology of digestive enzymes. Thus, one of our goals was to perform a curated gene annotation of α-amylases (amy2) and alanine aminopeptidases (anpep) in the genome of P. orbignyanus. This may help us better understand the evolution of these digestive enzymes and the dietary preferences of the fish. In this work, we identified two different copies of the amy2 gene and one copy of the anpep gene. The predicted protein products were analyzed and found to contain important residues and domains that contribute to enzymatic activity and stability. The genes were modeled using AlphaFold, and we were able to identify key residues involved in catalysis when compared to the resolved 3D structures. Consistent with other studies, these results suggest that this flatfish has the genetic capacity for initial carbohydrate digestion and final protein digestion. In addition, phylogenetic reconstruction analyses were performed for these two gene families and fish with diverse dietary preferences. Phylogenetic and comparative genomic analyzes revealed no relationship between gene copy number and dietary preference in fish. Through the use of comparative genomics, structural biology, and computational biology, this work provides valuable insights into the genetic basis, evolutionary relationships, and functional properties of these enzymes in black flounder.