CHARACTERIZING THE ROLE OF BRANCHED CHAIN KETOACID DEHYDROGENASE
Open Access
- Author:
- Paulosky, Kayla E
- Area of Honors:
- Immunology and Infectious Disease
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Manuel Llinás, Thesis Supervisor
Dr. Pamela A. Hankey-Giblin, Thesis Honors Advisor - Keywords:
- P. falciparum
Plasmodium
malaria
disease
metabolism
BCKDH
TCA cycle
branched chain keto acid dehydrogenase
plasmodium falciparum
metabolism of p. falciparum
malaria drug targets
malaria metabolism
malaria TCA cycle - Abstract:
- The protozoan parasite, Plasmodium falciparum causes the most virulent form of malaria in humans and threatens the lives of millions of people every year. Although the global mortality from malaria is decreasing, there is a fear that current antimalarial drugs are becoming ineffective due to parasite resistance. This is causing a global health crisis that is creating an intense pressure for the discovery of new antimalarial targets. Many antimetabolites have been very successful antimalarials in the past, leading to the study of unique aspects of parasite metabolism to identify new therapeutic targets. For example, P. falciparum is believed to have repurposed the role of branch chain keto acid dehydrogenase (BCKDH) to substitute for a critical pyruvate dehydrogenase (PDH)-like function based on previous studies of BCKDH in other Plasmodium spp. This thesis explores the role of BCKDH during the blood stage development of the malaria parasite P. falciparum, using both a pharmacological and a genetic approach. In addition to the construction of the plasmids to generate a bckdh knockout, we tested the effect of inhibition of the mitochondrial pyruvate carrier with UK-5099, a known potent inhibitor, using liquid-chromatography mass spectrometry (LC-MS). To supplement LC-MS data, asexual parasite growth was observed under UK-5099 for four days. The results of UK-5099 reveal the immediate flexibility of the parasite’s metabolism in the face of metabolite deficient conditions. However, asexual parasites underwent morphological changes and showed signs of death when UK-5099 induced acetyl-CoA deficiency was extended over four days. Therefore, we believe that BCKDH has a PDH-like function in P. falciparum and based on the results of the UK-5099 experiments, it is assumed that without the function of BCKDH, the parasite’s immediate changes in metabolic flux would not be capable of supporting long-term parasite survival. This provides evidence that BCKDH could be a potential drug target for antimalarial drugs.