Cloning and Expression of an Oligopeptidase, PepO, with Novel Specificity from Lactobacillus rhamnosus HN001 (DR20)
AUTOR(ES)
Christensson, Camilla
FONTE
American Society for Microbiology
RESUMO
Oligopeptidases of starter and nonstarter lactic acid bacteria contribute to the proteolytic events important in maturation and flavor development processes in cheese. This paper describes the molecular cloning, expression, and specificity of the oligopeptidase PepO from the probiotic nonstarter strain Lactobacillus rhamnosus HN001 (DR20). The pepO gene encodes a protein of 70.9 kDa, whose primary sequence includes the HEXXH motif present in certain classes of metallo-oligopeptidases. The pepO gene was cloned in L. rhamnosus HN001 and overexpressed in pTRKH2 from its own promoter, which was mapped by primer extension. It was further cloned in both pNZ8020 and pNZ8037 and overexpressed in Lactococcus lactis subsp. cremoris NZ9000 from the nisA promoter. The purified PepO enzyme demonstrated unique cleavage specificity for αs1-casein fragment 1–23, hydrolyzing the bonds Pro-5-Ile-6, Lys-7-His-8, His-8-Gln-9, and Gln-9-Gly-10. The impact of this enzyme in cheese can now be assessed.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=126545Documentos Relacionados
- Heat and Osmotic Stress Responses of Probiotic Lactobacillus rhamnosus HN001 (DR20) in Relation to Viability after Drying
- Identification and Characterization of Lactobacillus helveticus PepO2, an Endopeptidase with Post-Proline Specificity
- Cloning and Characterization of a Prolinase Gene (pepR) from Lactobacillus rhamnosus
- Characterization of an intracellular oligopeptidase from Lactobacillus paracasei.
- Analysis of the Fecal Microflora of Human Subjects Consuming a Probiotic Product Containing Lactobacillus rhamnosus DR20