dc.contributor.author |
Saleh, Lana Y. |
en_US |
dc.contributor.author |
Youngstown State University. Dept. of Chemistry. |
en_US |
dc.date.accessioned |
2011-01-31T14:16:58Z |
|
dc.date.accessioned |
2019-09-08T02:36:36Z |
|
dc.date.available |
2011-01-31T14:16:58Z |
|
dc.date.available |
2019-09-08T02:36:36Z |
|
dc.date.created |
1999 |
en_US |
dc.date.issued |
1999 |
en_US |
dc.identifier.other |
b18421192 |
en_US |
dc.identifier.uri |
http://www.ohiolink.edu/etd/view.cgi?ysu999190551 |
en_US |
dc.identifier.uri |
http://jupiter.ysu.edu/record=b1842119 |
en_US |
dc.identifier.uri |
http://hdl.handle.net/1989/6124 |
|
dc.description |
xi, 56 leaves : ill. ; 29 cm. |
en_US |
dc.description |
Thesis (M.S.)--Youngstown State University, 1999. |
en_US |
dc.description |
Includes bibliographical references (leaves ). |
en_US |
dc.description.abstract |
The chemical mechanism by which orotidylate decarboxylase (ODCase) catalyzes
the formation of uridylate (UMP) from orotidylate (OMP) is apparently different from
any of the common decarboxylation routes seen with other enzymes. ODCase is the final
enzyme of the de novo pyrimidine biosynthetic pathway and it displays one of the largest
rate enhancements ever measured. Different mechanisms have been suggested to explain
the mechanistic action of ODCase. Our group suggested a model for this decarboxylation
that involves proton donation to the transition state in a concerted
protonationldecarboxylation mechanism and possible participation of a Zn+z ion. Yeast
ODCase was purified from any contaminating proteins whereas its mutant (K93C) was
partially purified. Thio-substituted analogues were used as inhibitors to probe the active
site of the enzyme. The inhibition constants of these compounds were measured by
14COZ displacement assays, and their pKa's were determined by spectrophotometric
assays. IH NMR spectroscopy of ODCase in complex with barbituric acid ribonucleotide
(BMP) at different DzO concentrations and UMP at 10% DzO reveals downfield signals,
possibly identifying hydrogen bonds between the enzyme and the inhibitor. The two
farthest downfield signals in the spectra are absent in the free ODCase spectrum. Our
proposed catalytic mechanism and the results obtained from the experiments are to be
discussed in this thesis. |
en_US |
dc.description.statementofresponsibility |
by Lana Y. Saleh. |
en_US |
dc.language.iso |
en_US |
en_US |
dc.relation.ispartofseries |
Master's Theses no. 0654 |
en_US |
dc.subject.classification |
Master's Theses no. 0654 |
en_US |
dc.subject.lcsh |
Theses (Master's) |
en_US |
dc.title |
Orotidine-5-Monophosphate Decarboxylase: Purification and spectral studies, / |
en_US |
dc.type |
Thesis |
en_US |