A bioinformatic approach towards designing a human papillomavirus vaccine based on L1 capsid protein sequence of HPV45

Abstract

The cost of HPV vaccination is relatively expensive in low- to middle-income countries, hindering the introduction of HPV vaccination in these areas, although infection cases are high. In this study we designed a vaccine candidate based on L1 protein from Human Papillomavirus Subtype 45 (HPV45). Explorations of L1 HPV45 sequences from NCBI and Uniprot databases generated a consensus sequence, which was then optimised to improve its antigenicity character, whilst retaining the same epitope sites as observed in the consensus. Characteristics of the designed molecule was assessed, to ascertain its potential immunogenicity and good physicochemical characters. The study showed no major difference between our designed protein and either the Indonesian L1 HPV45 sequence (GenBank: QRG45832.1) (apart from two amino acids, N379 and G383), or the consensus sequence (apart from three amino acids, N81, T329, and H392). These differences do not seem to affect the 3D-structural similarities of the proteins. The designed protein is a non-allergenic, 60 kDa protein, with pI 8.61. It is relatively thermostable, with aliphatic index 75.26. The GRAVY score suggested that the protein is soluble in water. Pichia was selected as the expression host, because, unlike in E. coli, the protein has longer half-life and do not form inclusion bodies in the yeast.