title: Purification and N-terminal amino acid sequence determination of the cell-wall-bound proteinase from Lactobacillus paracasei subsp. paracasei.
abstract: The cell-wall-bound proteinase from Lactobacillus paracasei subsp. paracasei NCDO 151 was purified to homogeneity by anion-exchange and hydrophobic-interaction chromatography, chromatofocusing and gel-filtration. The purification resulted in a 600-700-fold increase in specific activity of the proteinase and the final yield was approximately 20%. Upon chromatofocusing, two proteolytically active components, termed pro135 and pro110, were detected. pro135 had an isoelectric point of 4.2. It had an Mr of about 300,000 as determined by gel-filtration and 135,000 as judged by SDS-PAGE, indicating that it may exist as a dimer in its native state. pro110 had an isoelectric point of 4.4, and an Mr of about 150,000 as determined by gel-filtration and 110,000 as judged by SDS-PAGE. pro110 appears to be a degradation product of pro135 as they have the same N-terminal amino acid sequence. The first N-terminal amino acid was ambiguous for both components, whereas the sequence from the second to the ninth amino acid was Ala-Lys-Ala-Asn-Ser-Met-Ala-Asn. This is identical to the corresponding sequence of the lactococcal cell-wall-bound proteinases. Although the Lactobacillus proteinase was a little smaller than the lactococcal proteinase, their purification characteristics were very similar, suggesting that these proteinases are related.
authors.affiliation: Norwegian Food Research Institute, As.
authors.forename: H
authors.initials: H
authors.lastname: Naes
authors.forename: J
authors.initials: J
authors.lastname: Nissen-Meyer
mesh_terms: D000595:Amino Acid Sequence; D002473:Cell Wall / Q000201:enzymology*; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D010450:Endopeptidases / Q000737:chemistry* / Q000302:isolation & purification; D007778:Lactobacillus / Q000201:enzymology* / Q000648:ultrastructure; D008969:Molecular Sequence Data
chemical_list: D010450:Endopeptidases