A Comparative Enzyme Kinetics Study of Glyceraldehyde-3-Phosphate Dehydrogenase in the Coral Acropora millepora and its Symbiotic Dinoflagellete Symbiodinium
The diverse ecosystem of coral reefs is threatened by increases in sea surface temperature due to global warming, which can trigger an event called coral bleaching. The survival of coral reefs thus depends largely on the ability of corals to adapt to temperature extremes. Studies to date have focused on determining the genetic variability in the coral and its single-celled dinoflagellate symbiont, Symbiodinium, in order to estimate the adaptive potential of the coral populations to survive climate changes. However, biochemical comparisons of key enzymes between the coral and its endosymbiont have received less attention. Determining the differences in kinetic parameters of key enzymes may help us better understand coral bleaching events during which Symbiodinium is ejected by its coral host. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a universally expressed glycolytic enzyme. I have determined the sequences of GAPDH from the coral Acropora millepora and Symbiodinium, which inhabits it, in order to transform the gene into E. coli. I have expressed recombinant GAPDH from both species and performed kinetic analyses on the enzymes. Kinetic data from GAPDH isolated from A. millepora followed traditional Michaelis-Menten kinetics, however GAPDH from Symbiodinium appears to be an extremely labile protein, making analysis difficult. Protein modeling has shown that GAPDH from both species is highly conserved, yet with some distinct features.
Franklin and Marshall College Archives, Undergraduate Honors Thesis 2014
- F&M Theses Collection