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.
- MeSH
- bakteriální geny genetika MeSH
- bakteriální proteiny genetika metabolismus MeSH
- cysteinové endopeptidasy genetika metabolismus MeSH
- financování organizované MeSH
- kaseiny metabolismus MeSH
- katalytická doména genetika MeSH
- Lactobacillus enzymologie genetika MeSH
- Lactococcus lactis enzymologie genetika MeSH
- potravinářská mikrobiologie MeSH
- substituce aminokyselin MeSH
- substrátová specifita MeSH
- subtilisin genetika MeSH
- sýr mikrobiologie MeSH
- Publikační typ
- srovnávací studie MeSH