Expression and Purification of the Full-length E1-E2 Protein Complex from Human Papillomavirus type16

• Janna Baltar, Medical Laboratory Science, University of Delaware

• Subhasis Biswas, Medical and Molecular Sciences, University of Delaware

The human papillomavirus (HPV) is a significant public health concern, as it is the primary causative agent of cervical cancer and other malignancies. Furthermore, HPV is a major risk factor for oropharyngeal cancers. While there are over 200 variants of HPV, the current vaccine only targets 9 of these variants. 

HPV is a double-stranded DNA virus that encodes two replicative proteins, E1 and E2, which are essential for viral replication. The E1 protein is a DNA helicase that unwinds the viral genome, while the E2 protein acts as an initiator protein for the viral replication. Previous studies from the lab and literature suggested that E1 and E2 proteins might exist as a complex in nature. However, no comprehensive analysis of the full-length E1-E2 proteins complex has been reported to date. In this study, we aimed to clone, express, and purify the full-length E1- E2 protein complex from an E. coli expression system. 

The E1 and E2 genes from HPV16 were cloned into different vectors and then co-transformed into BL21 DE3 RIPL E. coli cells. The recombinant complex was then expressed and partially purified using metal affinity chromatography. The partially purified E1-E2 complex was verified using Western Blot analysis. Further optimizations are required to purify the E1-E2 complex to near homogeneity. Once purified, this recombinant E1-E2 complex will be used for further functional studies, such as examining the interaction between E1 and E2 proteins and investigating their DNA-binding properties.