In situ Synthesis and Immobilization of Enzyme Molecules on Microreactor Array Chips

The improved catalytic activity of enzymes is required in various fields. Enzymes have conventionally been improved by the screening of bacteria possessing mutant enzymes. However, the screening conditions are limited since screening requires the growth of bacteria. Here, we report the development of a protein microarray for the analysis of enzymatic activity. A his-tagged enzyme is synthesized in situ and immobilized on the microarray, which is composed of microreactors with a diameter and depth of 4 μm and a density of 1.0 x 106 reactors/cm2. β-glucosidase, synthesized in situ using a cell-free synthesis system, was immobilized on the microreactor array chip and its catalytic activity was observed. This enzyme-immobilized microarray is expected to enable the rapid and quantitative screening of enzymes.