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Updated: Oct 23, 2025

Screening for Thermotoga maritima Membrane-Bound Pyrophosphatase Inhibitors
Published on: November 23, 2019
Thermostable adenosine 5'-monophosphate phosphorylase from Thermococcus kodakarensis forms catalytically active
Sarah Kamel1, Miriam C Walczak1,2, Felix Kaspar1,2
1Chair of Bioprocess Engineering, Technische Universität Berlin, Straße des 17. Juni 135, 10623, Berlin, Germany.
Abstract:
Catalytically active inclusion bodies (CatIBs) produced in Escherichia coli are an interesting but currently underexplored strategy for enzyme immobilization. They can be purified easily and used directly as stable and reusable heterogenous catalysts. However, very few examples of CatIBs that are naturally formed during heterologous expression have been reported so far. Previous studies have revealed that the adenosine 5'-monophosphate phosphorylase of Thermococcus kodakarensis (TkAMPpase) forms large soluble multimers with high thermal stability. Herein, we show that heat treatment of soluble protein from crude extract induces aggregation of active protein which phosphorolyse all natural 5'-mononucleotides. Additionally, inclusion bodies formed during the expression in E. coli were found to be similarly active with 2-6 folds higher specific activity compared to these heat-induced aggregates. Interestingly, differences in the substrate preference were observed. These results show that the recombinant thermostable TkAMPpase is one of rare examples of naturally formed CatIBs.
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