Work

A Single Molecule Perspective on the Functional Diversity of in Vitro Evolved β-Glucuronidase

Year: 2014

Type: article

Abstract: The mechanisms that drive the evolution of new enzyme activity have been investigated by comparing the kinetics of wild-type and in vitro evolved β-glucuronidase (GUS) at the single molecule level. Several hundred single GUS molecules were separated in large arrays of 62,500 ultrasmall reaction chambers etched into the surface of a fused silica slide to observe their individual substrate turnover rates in parallel by fluorescence microscopy. Individual GUS molecules feature long-lived but divergent activity states, and their mean activity is consistent with classic Michaelis-Menten kinetics. The large number of single molecule substrate turnover rates is representative of the activity distribution within an entire enzyme population. Partially evolved GUS displays a much broader activity distribution among individual enzyme molecules than wild-type GUS. The broader activity distribution indicates a functional division of work between individual molecules in a population of partially evolved enzymes that-as so-called generalists-are characterized by their promiscuous activity with many different substrates.

Source: Journal of the American Chemical Society

DOI: 10.1021/ja412379p

Authors: Raphaela B. Liebherr, Max Renner, Hans H. Gorris

Institution: University of Regensburg

Language: English

Topic: Enzyme Catalysis and Immobilization

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: hybrid

Estimated APC paid: $4,500

Funder: Deutsche Forschungsgemeinschaft