Enzymes make an excellent choice for biocatalysis in industrial applications, due to their ability to carry out complex reactions under mild reaction conditions. However, they are easily denatured with changes in surrounding conditions, therefore it is crucial to stabilize their structure and function to retain their activity for longer periods. This can be achieved through their immobilization or encapsulation into a matrix. Encapsulation of enzymes into confined spaces such as virus-like particles (VLPs), liposomes, and polymerosomes, are shown to protect them from environmental assault and allow us to study their behavior without any interference from other molecules. The encapsulation, however, modulates the activity of enzyme when compared with the free enzyme. Macromolecular crowding, resulting from the high-density packaging of enzymes inside these caged systems, confinement-induced denaturation or self-association, and slower diffusional mobility of enzymes and substrate molecules are used in conjunction to rationalize the outcome of enzyme encapsulation. We have developed a methodology that has allowed us to control the amount of packaging and the degree of packing density of enzymes inside the VLPs (derived from P22), thereby allowing us to dissect the role of confinement and crowding onto these enzyme systems. Additionally, morphogenesis of P22 VLPs offer cages with different porosities that have allowed us to determine the involvement of diffusion controlled enzyme kinetics. This work will highlight the motivation that led to the development of this methodology, followed by its utilization to tease out underlying phenomenon responsible for the modulation of enzymatic rates.  We anticipate that this study will help us engineer nanoreactors with better performance and catalytic efficiencies, thus making them more suitable for nano-technological and industrial applications.

Impact of confinement and crowding on the kinetics of enzyme encapsulated in virus-like particles

2019 Fall National Meeting

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