Variation in specificity of the PrtP extracellular proteinases in Lactococcus lactis and Lactobacillus paracasei subsp. paracasei

Abstract

Comparison of cell-wall-bound extracellular proteinases (CEPs) from Lactobacillus paracasei (LBP) ssp. paracasei natural isolates BGHN14, BGAR75 and BGAR76 with Lactococcus lactis (LCL) ssp. cremoris Wg2, in their action on alpha(S1)-, beta- and kappa-casein was done. The CEPs of LBP strains were able to degrade alpha(S1)- and beta-caseins and their caseinolytic specificity depended on the type of buffer used. These CEPs, compared with LCL Wg2, differ in four amino acid residues in small segments predicted to be involved in substrate binding. The most striking features of this comparison are the presence of Ala instead of Ser(329) and the presence of Thr instead of Asn(256) and Ala(299), in the subtilisin-like region of the CEP in LBP natural isolates. Additional conservative amino acid substitution Leu to Ile(364) was found.

Genetic, enzymatic and metabolite profiling of theLactobacillus caseigroup reveals strain biodiversity and potential applications for flavour diversification

“…Lactococcus lactis subsp. cremoris Wg2 was used as a CEP-positive control strain, having been confirmed as such in a previous study (Kok et al 1988;Laan and Konings 1989;Nikolic et al 2009), and its CEP activity was 205Á33 arbitrary fluorescence units. The strains DPC2071, DPC4206, DPC3990, (Fig.…”

Peptidomic study of casein proteolysis in bovine milk by Lactobacillus casei PRA205 and Lactobacillus rhamnosus PRA331

“…Overall, these evidences support that the observed CEP activities could be due to the mixed PI/PIII-type proteases. PI/PIII-type proteases have been characterized in lactobacilli (Fernandez de Palencia et al, 1997;Sadat-Mekmene et al, 2011aVillegas et al, 2015 and lactococci (Nikolić, Tolinački, Fira, Golić, & Topisirović, 2009). In particular, like PRA331, Lb.…”

Peptide and amino acid metabolism is controlled by an OmpR‐family response regulator in Lactobacillus casei

“…Therefore, knowledge on L. casei CEP activity and regulation is of great interest both for food production and for human health. A number of reports have dealt with the characterization of L. casei CEP activity (Ezzat et al, 1988;Naes and Nissen-Meyer, 1992;Fern andez de Palencia et al, 1997;Nikolić et al, 2009;Lozo et al, 2011;Sfaxi et al, 2012); however, very little is known about the regulation of the expression of CEP in this organism and other lactobacilli. The cloning of the L. casei CEP-encoding gene, prtP, revealed the presence of a neighboring and divergently transcribed gene, prtM (Holck and Naes, 1992) (named prsA in the L. casei BL23 genome annotation).…”