Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
48
pubmed:dateCreated
2005-11-28
pubmed:abstractText
Pancreatic lipase is a soluble globular protein that must undergo structural modifications before it can hydrolyze oil droplets coated with bile salts. The binding of colipase and movement of the lipase lid open access to the active site. Mechanisms triggering lid mobility are unclear. The *KNILSQIVDIDGI* fragment of the lid of the human pancreatic lipase is predicted by molecular modeling to be a tilted peptide. Tilted peptides are hydrophobicity motifs involved in membrane fusion and more globally in perturbations of hydrophobic/hydrophilic interfaces. Analysis of this lid fragment predicts no clear consensus of secondary structure that suggests that its structure is not strongly sequence determined and could vary with environment. Point mutations were designed to modify the hydrophobicity profile of the [240-252] fragment and their consequences on the lipase-mediated catalysis were tested. Two mutants, in which the tilted peptide motif was lost, also have poor activity on bile salt-coated oil droplets and cannot be reactivated by colipase. Conversely, one mutant in which a different tilted peptide is created retains colipase dependence. These results suggest that the tilted hydrophobicity pattern of the [240-252] fragment is neither important for colipase binding to lipase, nor for interfacial binding but is important to trigger the maximal catalytic efficiency of lipase in the presence of bile salt.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
2
pubmed:volume
280
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
40074-83
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:16179352-Algorithms, pubmed-meshheading:16179352-Binding Sites, pubmed-meshheading:16179352-Catalysis, pubmed-meshheading:16179352-Dose-Response Relationship, Drug, pubmed-meshheading:16179352-Humans, pubmed-meshheading:16179352-Hydrogen-Ion Concentration, pubmed-meshheading:16179352-Hydrolysis, pubmed-meshheading:16179352-Kinetics, pubmed-meshheading:16179352-Lipase, pubmed-meshheading:16179352-Models, Molecular, pubmed-meshheading:16179352-Models, Statistical, pubmed-meshheading:16179352-Mutation, pubmed-meshheading:16179352-Pancreas, pubmed-meshheading:16179352-Peptides, pubmed-meshheading:16179352-Plant Oils, pubmed-meshheading:16179352-Plasmids, pubmed-meshheading:16179352-Point Mutation, pubmed-meshheading:16179352-Protein Conformation, pubmed-meshheading:16179352-Protein Structure, Secondary, pubmed-meshheading:16179352-Triglycerides
pubmed:year
2005
pubmed:articleTitle
Role of the lid hydrophobicity pattern in pancreatic lipase activity.
pubmed:affiliation
Centre de Biophysique Moléculaire Numérique, Faculté Agronomique, 5030 Gembloux, Belgium.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't