Linked Life Data

8995215

Source:http://linkedlifedata.com/resource/pubmed/id/8995215

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1997-2-18
pubmed:abstractText
Pancreatic lipase is characterized by increased activity against water-insoluble substrates and by dependence on another protein, colipase, for binding to the substrate interface. In most models of pancreatic lipase activity, colipase functions to anchor lipase on the substrate interface. Recent studies of the x-ray crystal structure of the complex between colipase and lipase suggest another function for colipase in maintaining the active conformation of lipase. We tested this hypothesis by introducing mutations into colipase at position 15, a residue that contacts the lid domain lipase in the open conformation. Multiple mutant colipases were expressed and shown to have decreased activity. To further investigate the function of the interaction between Glu15 of colipase and lipase, we examined one mutant, E15R, in detail. This mutant had 175-fold less activity compared with wild-type colipase. Although E15R had decreased activity, it was as effective as wild-type lipase in anchoring lipase to mixed emulsions of bile salt and tributyrin. The importance of the interaction with the lid domain was tested by determining the activity of E15R with lid deletion mutants of lipase. E15R was as active as wild-type colipase with these mutant lipases. These results indicate that Glu15 is critical for activity of the colipase-lipase complex at an interface and that colipase has a function in lipolysis in addition to anchoring lipase to an interface. We propose that this function is to stabilize the lid domain of lipase in the open conformation, thereby facilitating lipolysis.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
3
pubmed:volume
272
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
9-12
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Colipase stabilizes the lid domain of pancreatic triglyceride lipase.
pubmed:affiliation
Washington University School of Medicine, Department of Pediatrics, St. Louis Children's Hospital, Missouri 63110, USA. Lowe@kidsa1.wustl.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't