Show simple item record

dc.contributor.advisorMantle, Tim
dc.contributor.authorBrowne, Seamus
dc.date.accessioned2019-04-29T14:38:25Z
dc.date.available2019-04-29T14:38:25Z
dc.date.issued2006
dc.identifier.citationSeamus Browne, 'Mechanistic studies on human liver Biliverdin-IX beta reductase', [thesis], Trinity College (Dublin, Ireland). School of Biochemistry and Immunology, 2006, pp 305
dc.identifier.otherTHESIS 7976
dc.identifier.urihttp://hdl.handle.net/2262/86228
dc.description.abstractThe reaction mechanism of human biliverdin-IXβ reductase (BVR-B) has been investigated using a number of approaches. The preference for NADPH over NADH has been examined using site-directed mutagenesis. The crystal structure of BVR-B, reported by Pereira et al. (2001), shows that Arg-35 and Arg-78 interact with the 2'- phosphate of NADP+ and indicates Arg-39 may also be involved in NADPH binding. BVR-B exhibits pronounced substrate inhibition preventing detailed kinetic characterisation of the enzyme's biliverdin reductase activity. BVR-B has previously been shown to be identical to flavin reductase. The flavin reductase activity of BVR-B was used in an initial rate study that revealed that the dominant residue in determining the enzyme’s preference for NADPH is Arg-35. Replacement of this residue with alanine or serine resulted in the apparent Km NADPH approaching that of the apparent Km for NADH. The k cat, with FMN as the second substrate, was only slightly reduced. Replacing Arg-78 and Arg-39 had essentially no effect on the Km NADPH or the k cat values with FMN as the variable substrate. These results show good agreement with preliminary experiments that model NADP+ desorption using steered molecular dynamics. These calculations, performed by Dr Liam Smith show that release of the guanido-terminus of Arg-35 from its "locking" position over the adenine of NADP+ appears to permit the "unwrapping" o f Arg-78 and Arg-39.
dc.format1 volume
dc.language.isoen
dc.publisherTrinity College (Dublin, Ireland). School of Biochemistry and Immunology
dc.relation.isversionofhttp://stella.catalogue.tcd.ie/iii/encore/record/C__Rb12734757
dc.subjectBiochemistry, Ph.D.
dc.subjectPh.D. Trinity College Dublin
dc.titleMechanistic studies on human liver Biliverdin-IX beta reductase
dc.typethesis
dc.type.supercollectionthesis_dissertations
dc.type.supercollectionrefereed_publications
dc.type.qualificationlevelDoctoral
dc.type.qualificationnameDoctor of Philosophy (Ph.D.)
dc.rights.ecaccessrightsopenAccess
dc.format.extentpaginationpp 305
dc.description.noteTARA (Trinity's Access to Research Archive) has a robust takedown policy. Please contact us if you have any concerns: rssadmin@tcd.ie


Files in this item

Thumbnail
Thumbnail

This item appears in the following Collection(s)

Show simple item record