Boosting Enzyme Performance: The Role of Amino Acids in Accelerating Reaction Kinetics
Research Poster Physical Sciences & Mathematics 2025 Graduate ExhibitionPresentation by Mastiyage Dona Chamika Goonetilleke
Exhibition Number 191
Abstract
The origin of life on Earth over 3.7 billion years ago, particularly the transition from non-living chemical systems to living organisms, remains one of the most profound and unresolved questions in science. A prevailing hypothesis suggests that life emerged through the compartmentalization of chemical precursors within membraneless structures in the primordial soup. Recent advances in understanding liquid-liquid phase separation have revealed that mixtures of small molecules, such as hydrotropes, can self-assemble into nanostructured solutions and promote chemical reactions. However, the role of the chirality of hydrotropic amino acids in modulating reaction rate has not been explored. This research project investigates the impact of amino acid hydrotropes on enzymatic reaction kinetics, focusing on the role of chirality in modulating the hydrolysis rates of substrates such as p-nitrophenyl phosphate (pNPP) and glucose-6-phosphate in the presence of alkaline phosphatase (AkP). Our findings demonstrate that amino acid solutions, particularly those containing proline and phenylalanine, can significantly alter enzymatic reaction rates. Notably, enantioselective interactions were observed, with L-amino acids exhibiting stronger binding affinity to the enzyme compared to their D-amino acid counterparts. This enantioselective binding may induce changes in the local water structure surrounding the enzyme, leading to conformational rearrangements that ultimately influence enzyme kinetics. These results suggest a potential mechanism by which amino acid hydrotropes could have played a role in prebiotic chemical evolution by modulating reaction dynamics in primordial environments. Further studies are underway to elucidate the precise molecular mechanisms underlying this phenomenon and its implications for the emergence of enzymatic activity in early life.
Importance
The origin of life over 3.7 billion years ago remains a mystery, with one theory suggesting it began in membrane-free structures within Earth’s primordial soup. Recent studies on liquid-liquid phase separation reveal that small molecules, like hydrotropes, can self-assemble into nanostructures and promote chemical reactions. However, the role of chirality in hydrotropic amino acids remains unexplored. We investigated how amino acids like proline and phenylalanine influence enzyme reactions, such as those involving alkaline phosphatase. Natural L-amino acids bind more strongly to enzymes than their D-forms, potentially altering water arrangements and enzyme shape, impacting function. Further research is needed to fully understand these processes and their implications for the origins of life.