Soluble expression of human glycoprotein Ibα in Escherichia coli through replacement of the N-terminal capping domain.

Glycoprotein Ibα (GpIbα), a family of LRR (leucine-rich repeat) proteins, is a membrane protein on the platelet, and plays an important role in atherothrombotic events. The complex formation of GpIbα with the von Willebrand Factor (vWF) has been revealed to lead to acute coronary syndrome (ACS) or stroke. A considerable attention has been paid to understand the biological functions of GpIbα and its regulation. However, difficulty with the soluble expression of human GpIbα in bacteria has hampered the relevant research. Herein, we present a soluble expression of GpIbα in Escherichiacoli by replacing the N-terminal capping domain of GpIbα with that of Internalin B using a computational approach. The resulting protein was expressed as a soluble form in E. coli, maintaining its structural feature and binding property for vWF. The present approach can be broadly used for the soluble expression of human LRR proteins in E. coli.