Linked Life Data

16099524

Source:http://linkedlifedata.com/resource/pubmed/id/16099524

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2005-11-8
pubmed:abstractText
Lactobacillus helveticus strains, one of the most nutritionally fastidious lactic acid bacteria, have a potent proteolytic system that makes them very interesting for different uses in the dairy industry. Its applications concern from cheese ripening to the preparation of fermented milk products with biologically active peptides. The cell-free extract (CFE) of Lactobacillus helveticus strain ITG LH1 was analysed by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE), using IPG immobiline dry strips (pH 4-7). With the aim to study the proteolytic enzymes expressed by Lactobacillus helveticus ITG LH1 grown in milk medium, a two step-chromatography methodology, based on ion exchange and affinity chromatography, was developed for the preparation of a peptidase-rich sub-proteome from the CFE of stationary growing cells. Several affinity chromatography columns were tested and among them a HiTrap Chelating column was selected as it provided the best performance for the enrichment in peptidases. Peptidase activities were studied using different beta-Naphtylamide (beta-NA) derivatives and specific activities were increased 50- to 100-fold by this chromatographic procedure. Sub-proteome characterisation was performed by 2D-PAGE, pH 4-7, followed by protein digestion with trypsin, analysis by MALDI-TOF mass spectrometry and subsequent database searches using peptide mass fingerprints. Among the most abundant proteins seven peptidases were present, namely the two general aminopeptidases (PepN, PepC), three dipeptidases (PepDA, PepV, PepQ) and two endopeptidases (PepO, PepO3), all of them corresponding to the catalytic classes of metallo- or cysteine-peptidases. Several stress proteins (such as heat shock proteins DnaK and GroEL) and other enzymes implied in bacterial metabolism, namely in the carbohydrate pathways (such as LDH), were also identified in the peptidase-rich sub-proteome.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0168-1605
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
105
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
119-29
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Isolation and characterisation of a Lactobacillus helveticus ITG LH1 peptidase-rich sub-proteome.
pubmed:affiliation
INRA, UMR Science et Technologie du Lait et de l'Oeuf, 65 rue de Saint Brieuc 35042, Rennes Cedex, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't