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Article
Hydrolysis of casein derived peptidesαS1-CN (f1-9) and β-CN (f193-209) by Lactobacillus helveticus peptidase deletion mutantsindicates the presence of a previously undetected endopeptidase
Applied and Environmental Microbiology
  • J. E. Christensen
  • Jeff Broadbent, Utah State University
  • J. L. Steele
Document Type
Article
Publisher
American Society of Microbiology
Publication Date
1-1-2003
Disciplines
Abstract

Peptides derived from hydrolysis of αS1-casein(f1-9) [αS1-CN(f1-9)] and β-CN(f193-209) with cell extracts of Lactobacillus helveticus CNRZ32 and single-peptidase mutants (ΔpepC, ΔpepE, ΔpepN, ΔpepO, and ΔpepX) were isolated by using reverse-phase high-performance liquid chromatography and were characterized by mass spectrometry. The peptides identified suggest that there was activity of an endopeptidase, distinct from previously identified endopeptidases (PepE and PepO), with specificity for peptide bonds C terminal to Pro residues. Identification of hydrolysis products derived from a carboxyl-blocked form of β-CN(f193-209) confirmed that the peptides were derived from the activity of an endopeptidase.

Citation Information
Christensen, J. E., J. R. Broadbent, and J. L. Steele. 2003. Hydrolysis of casein derived peptides αS1-CN (f1-9) and β-CN (f193-209) by Lactobacillus helveticus peptidase deletion mutants indicates the presence of a previously undetected endopeptidase. Appl. Environ. Microbiol. 69:1283-1286.