Elucidation of Enzyme Mechanisms to Understand the Regulation of Glycolytic Pathways and the TCA Cycle

Enzymes are macromolecular machines that accelerate reaction rates by 107 -fold. Enzymes regulate metabolism in general and the functioning of enzymes is tuned to maintain the flux of metabolites that control several physiological processes. Mutations or deletions in the amino acid sequences of enzymes result in a complete or partial loss of activity that further perturbs metabolic activities leading to changes in metabolic rates and hence several disorders. Enzymes participating in the glycolytic pathway and the TCA cycle are important to generate the building blocks for the synthesis of genetic material for the replication of disease-causing parasites. Hence, understanding the kinetic and chemical mechanisms of these enzymes is of paramount importance to regulate their activity and identify novel molecules to enhance the activity in the case of loss of function due to mutations. These efforts will help in the development of novel inhibitors against the parasite enzymes that can be further developed as therapeutics against several diseases.

The problem to be addressed in this research topic is how the activities of the glycolytic pathway and TCA cycle enzymes are regulated by their substrates, products, and downstream metabolites. It is known from several metabolic pathways that enzymes undergo changes in conformation depending on the concentration of different metabolites and interaction with other proteins. Mutations in the enzymes preclude these conformational changes that are needed for optimal enzyme activity and hence sustain metabolism for the synthesis of important biomolecules. Recent advances in gene sequencing, mass spectrometry, molecular dynamics, and simulations help us trace the underlying molecular bases for several disorders. The proposed research topic will include articles that address such problems using steady-state and pre-steady-state enzyme kinetics, crystallography, and NMR spectroscopy combined with the techniques mentioned above.

Topics of interest include, but are not limited to, the following:

• Correlation between kinetic behavior of enzymes and changes in metabolism
• Gene sequencing to identify mutations in enzymes and structure solution to elucidate the underlying causes for changes in metabolism
• Importance of enzyme dynamics in regulating metabolism was probed through NMR, molecular dynamics simulations, and mass spectrometry
• Protein-protein interactions regulating enzyme behavior and metabolic flux
• Post-translational modifications that affect enzyme activity and its interactions with other enzymes/metabolites

Information about the Team: Dr. Sourav Roy is currently working at St. Jude Children’s Cancer Research Hospital and Dr. Jingjing Li is working at Duke University. Dr. Nikolaos Labrou is the co-founder of the company Enzyceuticals.