Identificação e ação antimicrobiana de peptídeos de queijo minas artesanal da canastra

Abstract

Artisanal Minas cheese samples from Canastra of three producers located in the city of Medeiros - MG were evaluated for the antimicrobial peptides presence during 30 days after manufacture. Proteins and peptides soluble extracted from cheeses, which concentration ranged from 2.05 to 5.13 μg of proteins and peptides soluble/µL of solution were fractionated by liquid chromatography of reverse phase and the collected fractions were evaluated as the growth inhibitory action of E. coli. Fractions with antimicrobial action belonging to the second batch of the cheese A and the first batch of the cheese C, which concentrations ranged from 25 to 46 μg of protein and peptides soluble/mL of solution were sent to the MALDI-TOF/TOF and then, peptides were sequenced and identified using MASCOT DAEMON compared to the database UniProt. The peptide sequences RPKHPIKHQ, RPKHPIKHQG, RPKHPIKHQGLPQ and RPKHPIKHQGLPQE, identified as related to αs1-casein protein are fragments belonging to Isracidine, a peptide with confirmed antimicrobial action. The peptides HQPHQPLPPT and MHQPHQPLPPT identified are derived from β-casein protein and, despite being isolated in other studies, their biological activities are unknown. The peptides validation identified was performed using SCAFFOLD aplication.