Purification and amino acid sequence of lactocin 705, a bacteriocin produced by Lactobacillus casei CRL 705.
Lactobacillus casei CRL 705, isolated from a dry fermented sausage, produces an antibacterial peptide which is active against Listeria monocytogenes. Previous studies have shown that this compound is potentially useful to control food-borne pathogens in ground meat. In view of the potential application of this antimicrobial substance in food fermentation, a detailed biochemical analysis of this peptide is required. In this work, the purification and amino acid sequence of this bacteriocin is presented. The adsorption-desorption pH-dependent property of lactocin 705 was exploited for purification. The active extract was further subjected to RP-HPLC and SDS-PAGE. The active antimicrobial band was electroeluted from an SDS-PAGE gel and its amino acid sequence determined. Lactocin 705 had an estimated molecular weight of 3357.80 and an isoelectric point of 10.03. The peptide contains a high ratio of glycine residues and does not show any modified amino acids, like lanthionine or beta-methyllanthionine. The sequence was unique when compared to several databases.
Palacios
J
J
Centro de Referencia para Lactobacilos (CERELA)-CONICET, Tucumán, Argentina.
Vignolo
G
G
Farías
M E
ME
de Ruiz Holgado
A P
AP
Oliver
G
G
Sesma
F
F
D000595:Amino Acid Sequence; D001430:Bacteriocins / Q000737:chemistry / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D007780:Lacticaseibacillus casei / Q000737:chemistry*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D017433:Protein Structure, Secondary
D001430:Bacteriocins; C035728:lactocin