The structure of truncated recombinant human bile salt-stimulated lipase reveals bile salt-independent conformational flexibility at the active-site loop and provides insights into heparin binding.

Show simple item record Moore, SA Kingston, RL Loomes, KM Hernell, O Bläckberg, L Baker, HM Baker, EN
dc.coverage.spatial Netherlands 2022-06-13T23:27:36Z 2022-06-13T23:27:36Z 2001-09
dc.identifier.citation (2001). Journal of Molecular Biology, 312(3), 511-523.
dc.identifier.issn 0022-2836
dc.description.abstract Human bile salt-stimulated lipase (BSSL), which is secreted from the pancreas into the digestive tract and from the lactating mammary gland into human milk, is important for the effective absorption of dietary lipids. The dependence of BSSL on bile acids for activity with water-insoluble substrates differentiates it from other lipases. We have determined the crystal structure of a truncated variant of human BSSL (residues 1-5.8) and refined it at 2.60 A resolution, to an R-factor of 0.238 and R(free) of 0.275. This variant lacks the C-terminal alpha-helix and tandem C-terminal repeat region of native BSSL, but retains full catalytic activity. A short loop (residues 115-126) capable of occluding the active-site (the active site loop) is highly mobile and exists in two conformations, the most predominant of which leaves the active-site open for interactions with substrate. The bile salt analogue 3-[(3-cholamidopropyl)dimethylammonio]-1-propane sulfonic acid (CHAPS) was present in the crystallisation medium, but was not observed bound to the enzyme. However, the structure reveals a sulfonate group from the buffer piperizine ethane sulfonic acid (PIPES), making interactions with Arg63 and His115. His115 is part of the active-site loop, indicating that the loop could participate in the binding of a sulphate group from either the glycosaminoglycan heparin (known to bind BSSL) or a bile acid such as deoxycholate. Opening of the 115-126 active-site loop may be cooperatively linked to a sulphate anion binding at this site. The helix bundle domain of BSSL (residues 319-398) exhibits weak electron density and high temperature factors, indicating considerable structural mobility. This domain contains an unusual Asp:Glu pair buried in a hydrophobic pocket between helices alpha(H) and alpha(K) that may be functionally important. We have also solved the structure of full-length glycosylated human BSSL at 4.1 A resolution, using the refined coordinates of the truncated molecule as a search model. This structure reveals the position of the C-terminal helix, missing in the truncated variant, and also shows the active-site loop to be in a closed conformation.
dc.format.medium Print
dc.language eng
dc.publisher Elsevier BV
dc.relation.ispartofseries Journal of molecular biology
dc.rights Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated. Previously published items are made available in accordance with the copyright policy of the publisher.
dc.subject Animals
dc.subject Cattle
dc.subject Humans
dc.subject Bile Acids and Salts
dc.subject Deoxycholic Acid
dc.subject Heparin
dc.subject Recombinant Proteins
dc.subject Solvents
dc.subject Crystallization
dc.subject Crystallography, X-Ray
dc.subject Sequence Deletion
dc.subject Binding Sites
dc.subject Protein Conformation
dc.subject Protein Binding
dc.subject Glycosylation
dc.subject Pliability
dc.subject Models, Molecular
dc.subject Sterol Esterase
dc.subject Digestive Diseases
dc.subject Science & Technology
dc.subject Life Sciences & Biomedicine
dc.subject Biochemistry & Molecular Biology
dc.subject bile salt dependent lipase
dc.subject bile salt stimulated lipase
dc.subject carboxyl ester lipase
dc.subject cholesterol esterase
dc.subject HUMAN-MILK
dc.subject ACTIVATION
dc.subject ABSORPTION
dc.subject HYDROLASE
dc.subject COLIPASE
dc.subject COMPLEX
dc.subject 0601 Biochemistry and Cell Biology
dc.subject 0304 Medicinal and Biomolecular Chemistry
dc.subject 0605 Microbiology
dc.title The structure of truncated recombinant human bile salt-stimulated lipase reveals bile salt-independent conformational flexibility at the active-site loop and provides insights into heparin binding.
dc.type Journal Article
dc.identifier.doi 10.1006/jmbi.2001.4979
pubs.issue 3
pubs.begin-page 511
pubs.volume 312 2022-05-03T04:56:15Z
dc.rights.holder Copyright: The author en
dc.identifier.pmid 11563913 (pubmed)
pubs.end-page 523
pubs.publication-status Published
dc.rights.accessrights en
pubs.subtype Research Support, Non-U.S. Gov't
pubs.subtype Journal Article
pubs.elements-id 4045 Science Biological Sciences Science Research Maurice Wilkins Centre (2010-2014)
dc.identifier.eissn 1089-8638
dc.identifier.pii S0022-2836(01)94979-4
pubs.record-created-at-source-date 2022-05-03

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