Development and use of a microreactor for the study of biotransformations by a cross-linked γ-lactamase enzyme

Anne Marie Hickey (1) , Bongkot Ngamsom (2) , Charlotte Wiles (2) , Gillian M Greenway (2) , Paul Watts (2) , Jennifer A Littlechild (2)

1 School of Biosciences
2 Chemistry

A (+)-γ-lactamase was precipitated, cross-linked and the resulting solid crushed prior to immobilization within a capillary column micro reactor. The micro reactor was subsequently used to study enzyme stability, activity, kinetics and substrate specificity. The thermophilic (+)-γ-lactamase retained 100 % of its initial activity at the assay temperature, 80 şC, for 6 h and retained 52 % activity after 10 h, indicating the advantage of immobilization. This high stability of the immobilized enzyme provided the advantage that it could be utilized to screen many compounds in the microreactor system. This advantage overcame the fact that the immobilization process affected enzyme kinetics and activity, which was reduced (by 70%) compared to the free enzyme. In general, the enzyme displayed similar substrate specificity to that found in a previous study for the free enzyme, however, enhanced activity was seen towards one substrate, acrylamide. The system developed correlates well with the free enzyme in batch assay and indicates the suitability of the system for enzyme substrate screening, allowing a significant reduction in cost, due to the reduced amounts of enzyme, substrates and other assay constituents required.

Mots clés: Life Sciences

Anne Marie Hickey, Bongkot Ngamsom, Charlotte Wiles, Gillian M Greenway, Paul Watts, et al.. Development and use of a microreactor for the study of biotransformations by a cross-linked γ-lactamase enzyme. Biotechnology Journal, 2009, 4 (4), pp.510-n/a. ⟨10.1002/biot.200800302⟩. ⟨hal-00477776⟩