Computational design and experimental characterisation of a stable human heparanase variant

Heparanase is the only human enzyme known to hydrolyse heparin sulfate and is involved in many important physiological processes. However, it is also unregulated in many disease states, such as cancer, diabetes and Covid-19. It is thus an important drug target, yet the heterologous production of heparanase is challenging and only possible in mammalian or insect expression systems, which limits the ability of many laboratories to study it. Here we describe the computational redesign of heparanase to allow high yield expression in Escherchia coli. This mutated form of heparanase exhibits essentially identical kinetics, inhibition, structure and protein dynamics to the wild type protein, despite the presence of 26 mutations. This variant will facilitate wider study of this important enzyme and contributes to a growing body of literature that shows evolutionarily conserved and functionally neutral mutations can have significant effects on protein folding and expression.

Automated summary

This study describes the computational redesign of heparanase for high yield expression in Escherichia coli. Despite the presence of 26 mutations, this mutated form of heparanase exhibited similar kinetics, inhibition, structure, and protein dynamics to the wild type protein. This research facilitates wider study of this important enzyme and reveals the significant effects of evolutionarily conserved and functionally neutral mutations on protein folding and expression.