title: Enhanced expression of soluble human papillomavirus L1 through coexpression of molecular chaperonin in Escherichia coli.
abstract: The major recombinant capsid protein L1 of human papillomavirus (HPV) is widely used to produce HPV prophylactic vaccines. However, the quality of soluble and active expression of L1 in Escherichia coli was below the required amount. Coexpression with the chaperonin GroEL/ES enhanced L1 expression. Overexpressing GroEL/ES increased the soluble expression level of glutathione S-transferase-fused L1 (GST-L1) by approximately ∼3 fold. The yield of HPV type 16 L1 pentamer (L1-p) was ∼2 fold higher than that in a single expression system after purification through size-exclusion chromatograph. The expression and purification conditions were then optimized. The yield of L1-p was enhanced by ∼5 fold, and those of HPV types 18 and 58 L1-p increased by ∼3 and ∼2 folds, respectively, compared with that in the single expression system. Coexpressing the mono-site mutant HPV16 L1 L469A with GroEL/ES increased L1-p yield by ∼7 fold compared with strains expressing the wild-type L1 gene. L1-p was then characterized using circular dichroism spectra, UV-vis cloud point, dynamic light scattering and transmission electron microscope analyses. Results indicated that the conformation and biological characteristics of L1-p were identical to that of native L1. Hence, overexpressing chaperonin in E. coli can increase the expression level of GST-L1 and L1-p production after purification. This finding may contribute to the development of a platform for prophylactic HPV vaccines.
authors.affiliation: State Key Laboratory of Supramolecular Structure and Materials, Jilin University, No. 2699, Qianjin Street, Changchun, 130012, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Pan
authors.affiliation: Sichuan Tumor Hospital & Institute, 55, Renmin Nanlu, Section 4, Chengdu, 610041, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Zha
authors.affiliation: The State Engineering Laboratory of AIDS Vaccine, Jilin University, No. 2699, Qianjin Street, Changchun, 130012, China.
authors.forename: Xianghui
authors.initials: X
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Supramolecular Structure and Materials, Jilin University, No. 2699, Qianjin Street, Changchun, 130012, China. Electronic address: yqwu@jlu.edu.cn.
authors.forename: Yuqing
authors.initials: Y
authors.lastname: Wu
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D036022:Capsid Proteins / Q000235:genetics* / Q000378:metabolism; D018835:Chaperonin 10 / Q000235:genetics; D018834:Chaperonin 60 / Q000235:genetics; D002845:Chromatography; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D052162:Human papillomavirus 16 / Q000378:metabolism*; D052161:Human papillomavirus 18 / Q000378:metabolism*; D006801:Humans; D030361:Papillomavirus Infections / Q000378:metabolism*; D011487:Protein Conformation; D017510:Protein Folding; D011994:Recombinant Proteins / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D036022:Capsid Proteins; D018835:Chaperonin 10; D018834:Chaperonin 60; D011994:Recombinant Proteins
keywords: Coexpression; Expression level; GroEL/ES; HPV; L1 pentamer