Show simple item record

AuthorNienhaus, Karindc.contributor.author
Date of accession2016-03-14T11:54:19Zdc.date.accessioned
Available in OPARU since2016-03-14T11:54:19Zdc.date.available
Year of creation2002dc.date.created
AbstractMyoglobin (Mb) is a globular protein that binds small ligands (O2, CO, NO). It was realized early on that the x-ray structure lacked an access pathway for the ligand to the active site; consequently, protein fluctuations that open transient channels must be essential for its function. The aim of this thesis research was to elucidate the dynamic aspects of the ligand binding reaction, especially the role of internal protein cavities. The key strategy was to remove or strongly modify the cavities by simple competitive binding of xenon, and more elegantly using modern tools of protein engineering. The ligand bond in myoglobin is photolabile and can be dissociated by a short laser pulse. Fourier transform infrared (FTIR) spectroscopy was employed to follow CO migration through the protein. The spectroscopic work was done over a wide temperature range (3-300 K). For the wild type MbCO and a whole family of single point mutants, a number of photoproduct states have been identified that are associated with ligands trapped in different cavities in the protein. Local structural changes were shown to have significant effects on the accessibility of a particular site for CO. To connect the low-temperature spectroscopic data with physiological ligand binding, room temperature flash photolysis data were collected on MbCO mutant samples. A thermodynamic model of ligand binding was developed that considers the internal cavities as transient ligand storage sites. In this model, both bond formation and ligand entry and exit are slow processes compared with the equilibration among the internal sites. By fluctuating among the internal sites, the photolyzed ligands can take advantage of protein fluctuations and escape. The exact route(s) for ligand entry and exit remained obscure.dc.description.abstract
Languageendc.language.iso
PublisherUniversität Ulmdc.publisher
LicenseStandard (Fassung vom 03.05.2003)dc.rights
Link to license texthttps://oparu.uni-ulm.de/xmlui/license_v1dc.rights.uri
KeywordCavitydc.subject
KeywordFlash photolysisdc.subject
KeywordTemperature derivative spectroscopy (TDS)dc.subject
LCSHFourier transform infrared spectroscopydc.subject.lcsh
TitleSpectroscopic studies of ligand migration in myoglobindc.title
Resource typeDissertationdc.type
DOIhttp://dx.doi.org/10.18725/OPARU-83dc.identifier.doi
URNhttp://nbn-resolving.de/urn:nbn:de:bsz:289-vts-26827dc.identifier.urn
GNDMyoglobindc.subject.gnd
FacultyFakultät für Naturwissenschaftenuulm.affiliationGeneral
Date of activation2003-02-28T08:58:27Zuulm.freischaltungVTS
Peer reviewneinuulm.peerReview
Shelfmark print versionZ: J-H 10.014 ; W: W-H 7.310uulm.shelfmark
DCMI TypeTextuulm.typeDCMI
VTS ID2682uulm.vtsID
CategoryPublikationenuulm.category
Bibliographyuulmuulm.bibliographie


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record