Show simple item record

Files in this item

Cover for Studies of Malarial Parasite Chloroquine Resistance Transporter and Kinase Proteins: Key Targets for Evolving Drug Therapies
dc.contributor.advisorRoepe, Paul Den
dc.creatoren
dc.date.accessioned2017-06-13T13:50:29Zen
dc.date.created2017en
dc.date.issueden
dc.date.submitted01/01/2017en
dc.identifier.otherAPT-BAG: georgetown.edu.10822_1043824.tar;APT-ETAG: 3d669dcebf179ecff6598b5c1f4f0491; APT-DATE: 2017-10-25_10:04:08en-US
dc.identifier.urien
dc.descriptionPh.D.en
dc.description.abstractThe emergence of drug resistance is a developing problem in treating the global health burden that is Plasmodium (malaria) infections. Mutations in the Plasmodium falciparum chloroquine resistance transporter (PfCRT) have been shown to play a major role in quinolone antimalarial drug resistance. In P. falciparum, CRT is hypothesized to facilitate the leak of chloroquine (CQ) out of the parasite digestive vacuole, its site of action. Multiple isoforms of PfCRT have been identified around the globe, and each shows a variable degree of CQ transport. The current frontline treatment for infection is artemisinin combination therapy (ACT). Unfortunately, a delayed parasite clearance phenotype associated with reduced efficacy of artemisinin therapy has been identified in the field, which may lead to drug resistance.en
dc.description.abstractI have continued the use of an optimized CRT expression system in S. cerevisiae to elucidate drug transport ability. CQ resistance (CQR) is well understood in P. falciparum, but in Plasmodium vivax (another species of malaria), CQR remains a mystery. Multiple mutations in PfCRT are characteristic of drug resistant isolates, and contrary to PfCRT, the P. vivax orthologue (named PvCRT) primarily shows only single mutations in CRT. In this thesis, I measure the drug transport efficiencies of multiple Pf and PvCRT isoforms. My results show that there is a range of quinolone drug transport across the isoforms analyzed. Additionally, some CQR isolates expressing certain CRT isoforms likely have other genetic events that shape CQR.en
dc.description.abstractI also conducted the first extensive biochemical characterization of a novel drug target, P. falciparum PI3K (PfVps34). I optimized the PfVps34 gene for heterologous expression in yeast, purified the protein to homogeneity, and used a recently validated enzyme-linked immunosorbent assay (ELISA) to quantify enzyme activity and drug inhibition by measuring product formed per unit time. My results show that artemisinin drugs non-specifically target PfVps34, but require Fe2+ activation in order to cleave their endoperoxide bridge. I also determined PfVps34 to be the molecular target of a potent class of antimalarial drugs (designed to target human PI3Ks). These results lead to a better understanding of drug resistance as well as providing results to shape future drug development.en
dc.formatPDFen
dc.format.extent256 leavesen
dc.languageenen
dc.publisherGeorgetown Universityen
dc.sourceGeorgetown University-Graduate School of Arts & Sciencesen
dc.sourceChemistryen
dc.subjectPfCRTen
dc.subjectPfVps34en
dc.subjectPlasmodiumen
dc.subjectPvCRTen
dc.subject.lcshBiochemistryen
dc.subject.otherBiochemistryen
dc.titleStudies of Malarial Parasite Chloroquine Resistance Transporter and Kinase Proteins: Key Targets for Evolving Drug Therapiesen
dc.typethesisen
gu.embargo.lift-date2019-06-13en
gu.embargo.termscommon-2-yearsen


This item appears in the following Collection(s)

Show simple item record