- Science Director Dr. John Spence named Royal Society Fellow
- BioXFEL Graduate Student Joey Olmos (Rice) Earns NSF Graduate Research Fellowship
- Mapping Conformational Landscape Through Crystallography
- NSF BioXFEL researchers create a better way to find out ‘when’
- Taking the initiative on single particle imaging
- Thursday, 20 April 2017 11:17
Structural analysis of membrane proteins has traditionally been bottlenecked by the lack of sufficiently large amounts of pure, properly folded and functional membrane proteins. The issue is particularly important considering the fact that membrane proteins constitute a significant proportion of clinical drug targets.
Viral protein U (Vpu) is a type-III integral membrane protein encoded by Human Immunodeficiency Virus-1 (HIV- 1). It is expressed in infected host cells and plays several roles in viral progeny escape from infected cells, including down-regulation of CD4 receptors. But key structure/function questions remain regarding the mechanisms by which the Vpu protein contributes to HIV-1 pathogenesis. Here we describe expression of Vpu in bacteria, its purification and characterization. We report the successful expression of PelB-Vpu in Escherichia coli using the leader peptide pectate lyase B (PelB) from Erwinia carotovora. The protein was detergent extractable and could be isolated in a very pure form. We demonstrate that the PelB signal peptide successfully targets Vpu to the cell membranes and inserts it as a type I membrane protein. PelB-Vpu was biophysically characterized by circular dichroism and dynamic light scattering experiments and was shown to be an excellent candidate for elucidating structural models.