Refolding and in vitro characterization of human papillomavirus 16 minor capsid protein L2

2019 ◽  
Vol 400 (4) ◽  
pp. 513-522 ◽  
Author(s):  
Bastian Breiner ◽  
Laura Preuss ◽  
Nora Roos ◽  
Marcel Conrady ◽  
Hauke Lilie ◽  
...  

Abstract The minor capsid protein L2 of papillomaviruses exhibits multiple functions during viral entry including membrane interaction. Information on the protein is scarce, because of its high tendency of aggregation. We determined suitable conditions to produce a functional human papillomavirus (HPV) 16 L2 protein and thereby provide the opportunity for extensive in vitro analysis with respect to structural and biochemical information on L2 proteins and mechanistic details in viral entry. We produced the L2 protein of high-risk HPV 16 in Escherichia coli as inclusion bodies and purified the protein under denaturing conditions. A successive buffer screen resulted in suitable conditions for the biophysical characterization of 16L2. Analytical ultracentrifugation of the refolded protein showed a homogenous monomeric species. Furthermore, refolded 16L2 shows secondary structure elements. The N-terminal region including the proposed transmembrane region of 16L2 shows alpha-helical characteristics. However, overall 16L2 appears largely unstructured. Refolded 16L2 is capable of binding to DNA indicating that the putative DNA-binding regions are accessible in refolded 16L2. Further the refolded protein interacts with liposomal membranes presumably via the proposed transmembrane region at neutral pH without structural changes. This indicates that 16L2 can initially interact with membranes via pre-existing structural features.

2010 ◽  
Vol 84 (21) ◽  
pp. 11585-11589 ◽  
Author(s):  
Martina Bergant Marušič ◽  
Nina Mencin ◽  
Mia Ličen ◽  
Lawrence Banks ◽  
Helena Šterlinko Grm

ABSTRACT The human papillomavirus (HPV) minor capsid protein L2 plays important roles in the generation of infectious viral particles and in the initial steps of infection. Here we show that HPV-16 L2 protein is sumoylated at lysine 35 and that sumoylation affects its stability. Interestingly, the sumoylated form of L2 cannot bind to the major capsid protein L1, suggesting a mechanism by which capsid assembly may be modulated in an infected cell. Additionally, L2 appears to modulate the overall sumoylation status of the host cell. These observations indicate a complex interplay between the HPV L2 protein and the host sumoylation machinery.


2017 ◽  
Vol 61 (8) ◽  
Author(s):  
David Wensel ◽  
Yongnian Sun ◽  
Zhufang Li ◽  
Sharon Zhang ◽  
Caryn Picarillo ◽  
...  

ABSTRACT A novel fibronectin-based protein (Adnectin) HIV-1 inhibitor was generated using in vitro selection. This inhibitor binds to human CD4 with a high affinity (3.9 nM) and inhibits viral entry at a step after CD4 engagement and preceding membrane fusion. The progenitor sequence of this novel inhibitor was selected from a library of trillions of Adnectin variants using mRNA display and then further optimized for improved antiviral and physical properties. The final optimized inhibitor exhibited full potency against a panel of 124 envelope (gp160) proteins spanning 11 subtypes, indicating broad-spectrum activity. Resistance profiling studies showed that this inhibitor required 30 passages (151 days) in culture to acquire sufficient resistance to result in viral titer breakthrough. Resistance mapped to the loss of multiple potential N-linked glycosylation sites in gp120, suggesting that inhibition is due to steric hindrance of CD4-binding-induced conformational changes.


2015 ◽  
Vol 6 (4) ◽  
pp. 381-385 ◽  
Author(s):  
Ding-Yi Fu ◽  
Shi Jin ◽  
Dong-Dong Zheng ◽  
Xiao Zha ◽  
Yuqing Wu

2019 ◽  
Vol 10 (2) ◽  
pp. 82-89
Author(s):  
Silvia Tri Widyaningtyas ◽  
Sofy Meilany ◽  
Budiman Bela

Latar belakang: Secara alamiah protein kapsid L1 Human Papillomavirus (HPV) tipe 16 dapat mengalami auto assembly untuk membentuk Viral like particle (VLP). Terkait dengan penelitian vaksin HPV, VLP dapat digunakan untuk berbagai keperluan seperti vaksin, pseudovirion atau SpyTag-Spycatcher. Penelitian ini ditujukan untuk mendapatkan plasmid rekombinan yang digunakan untuk produksi protein L1 HPV 16. Metode: Gen penyandi protein L1 HPV 16 diklona ke dalam vector pQE80L, suatu plasmid yang mengandung sistem ekspresi untuk prokariota. DNA penyandi HPV 16 L1 disisipkan pada situs restriksi BamHI dan Hind III plasmid pQE80L. Plasmid rekombinan yang mengandung gen L1 HPV 16dikonfirmasi menggunakan PCR dan analisis enzim restriksi. Lebih lanjut untuk memastikan bahwa gen rekombinan L1 HPV 16 dapat diekspresikan dalam prokariota, plasmid rekombinan ditransformasikan ke bakteri Escherichia coli BL21 (DE3). Bakteri diinduksi dengan Isopropyl β-D-1-thiogalactopyranoside (IPTG) dengan berbagai konsentrasi dan berbagai waktu inkubasi. Hasil: protein rekombinan L1, berat 56 kDa, telah berhasil diekspresikan dalam sistem prokariota. Protein rekombinan L1 dapat dimurnikan menggunakan TalonR dalam kondisi denaturasi. Kesimpulan: gen L1 HPV 16 telah dikloning ke dalam pQE80L dan berhasil diekspresikan dalam sistem prokariota. (Health Science Journal of Indonesia 2019;10(2):82-9) Kata kunci: L1, HPV 16, cervical cancer   Abstract Background: Naturally Human Papillomavirus (HPV) type 16 L1 capsid protein can auto assemble to form Viral like particles (VLP). Concerning to vaccine development for HPV, VLP can be used for a variety of needs such as a vaccine, pseudovirion or SpyTag-Spycatcher. In this study, to obtain a vector expression that can be used in the production of HPV L1 protein, we cloned gene coding HPV 16 L1 protein into pQE80L a plasmid contains an expression system for prokaryote. Methods: The DNA coding HPV 16 L1 was inserted at BamHI and Hind III restriction sites of pQE80L plasmid. The recombinant plasmid containing the HPV L1 gene was confirmed using PCR colony and enzyme restriction. Further to ensure the recombinant HPV 16 L1 gene could be expressed in a prokaryote, the recombinant plasmid was transformed into bacteria Escherichia coli BL21 (DE3). The bacteria were induced with IPTG with various concentrations and various incubation time. Result: L1 recombinant protein, 56 kDa in weight, has successfully been expressed in prokaryote system. L1 recombinant protein can be purified using TalonR under denaturing conditions. Conclusion: L1 HPV 16 gene has been cloned into pQE80L and successfully expressed in prokaryote system. (Health Science Journal of Indonesia 2019;10(2):82-9) Keywords: L1, HPV 16, cervical cancer


2001 ◽  
Vol 75 (9) ◽  
pp. 4467-4472 ◽  
Author(s):  
Tim Veldman ◽  
Izumi Horikawa ◽  
J. Carl Barrett ◽  
Richard Schlegel

ABSTRACT The E6 and E7 oncogenes of human papillomavirus type 16 (HPV-16) are sufficient for the immortalization of human genital keratinocytes in vitro. The products of these viral genes associate with p53 and pRb tumor suppressor proteins, respectively, and interfere with their normal growth-regulatory functions. The HPV-16 E6 protein has also been shown to increase the telomerase enzyme activity in primary epithelial cells by an unknown mechanism. We report here that a study using reverse transcription-PCR and RNase protection assays in transduced primary human foreskin keratinocytes (HFKs) shows that the E6 gene (but not the E7 gene) increases telomerase hTERT gene transcription coordinately with E6-induced telomerase activity. In these same cells, the E6 gene induces a 6.5-fold increase in the activity of a 1,165-bp 5′ promoter/regulatory region of the hTERT gene, and this induction is attributable to a minimal 251-bp sequence (−211 to +40). Furthermore, there is a 35-bp region (+5 to +40) within this minimal E6-responsive promoter that is responsible for 60% of E6 activity. Although the minimal hTERT promoter contains Myc-responsive E-box elements and recent studies have suggested a role for Myc protein in hTERT transcriptional control, we found no alterations in the abundance of either c-Myc or c-Mad in E6-transduced HFKs, suggesting that there are other or additional transcription factors critical for regulating hTERT expression.


2006 ◽  
Vol 80 (13) ◽  
pp. 6691-6696 ◽  
Author(s):  
Luise Florin ◽  
Katrin A. Becker ◽  
Carsten Lambert ◽  
Thorsten Nowak ◽  
Cornelia Sapp ◽  
...  

ABSTRACT Papillomaviruses enter cells via endocytosis (H. C. Selinka et al., Virology 299:279-287, 2002). After egress from endosomes, the minor capsid protein L2 accompanies the viral DNA to the nucleus and subsequently to the subnuclear promyelocytic leukemia protein bodies (P. M. Day et al., Proc. Natl. Acad. Sci. USA 101:14252-14257, 2004), suggesting that this protein may be involved in the intracytoplasmic transport of the viral genome. We now demonstrate that the L2 protein is able to interact with the microtubule network via the motor protein dynein. L2 protein was found attached to microtubules after uncoating of incoming human papillomavirus pseudovirions. Based on immunofluorescence and coimmunoprecipitation analyses, the L2 region interacting with dynein is mapped to the C-terminal 40 amino acids. Mutations within this region abrogating the L2/dynein interaction strongly reduce the infectivity of pseudoviruses, indicating that this interaction mediates the minus-end-directed transport of the viral genome along microtubules towards the nucleus.


2016 ◽  
Vol 90 (14) ◽  
pp. 6314-6325 ◽  
Author(s):  
Mathieu Boxus ◽  
Michel Fochesato ◽  
Agnès Miseur ◽  
Emmanuel Mertens ◽  
Najoua Dendouga ◽  
...  

ABSTRACTAt least 15 high-risk human papillomaviruses (HPVs) are linked to anogenital preneoplastic lesions and cancer. Currently, there are three licensed prophylactic HPV vaccines based on virus-like particles (VLPs) of the L1 major capsid protein from HPV-2, -4, or -9, including the AS04-adjuvanted HPV-16/18 L1 vaccine. The L2 minor capsid protein contains HPV-neutralizing epitopes that are well conserved across numerous high-risk HPVs. Therefore, the objective of our study was to assess the capacity to broaden vaccine-mediated protection using AS04-adjuvanted vaccines based on VLP chimeras of L1 with one or two L2 epitopes. Several chimeric VLPs were constructed by inserting L2 epitopes within the DE loop and/or C terminus of L1. Based on the shape, yield, size, and immunogenicity, one of seven chimeras was selected for further evaluation in mouse and rabbit challenge models. The chimeric VLP consisted of HPV-18 L1 with insertions of HPV-33 L2 (amino acid residues 17 to 36; L1 DE loop) and HPV-58 L2 (amino acid residues 56 to 75; L1 C terminus). This chimeric L1/L2 VLP vaccine induced persistent immune responses and protected against all of the different HPVs evaluated (HPV-6, -11, -16, -31, -35, -39, -45, -58, and -59 as pseudovirions or quasivirions) in both mouse and rabbit challenge models. The degree and breadth of protection in the rabbit were further enhanced when the chimeric L1/L2 VLP was formulated with the L1 VLPs from the HPV-16/18 L1 vaccine. Therefore, the novel HPV-18 L1/L2 chimeric VLP (alone or in combination with HPV-16 and HPV-18 L1 VLPs) formulated with AS04 has the potential to provide broad protective efficacy in human subjects.IMPORTANCEFrom evaluations in human papillomavirus (HPV) protection models in rabbits and mice, our study has identified a prophylactic vaccine with the potential to target a wide range of HPVs linked to anogenital cancer. The three currently licensed vaccines contain virus-like particles (VLPs) of the L1 major capsid protein from two, four, or nine different HPVs. Rather than increasing the diversity of L1 VLPs, this vaccine contains VLPs based on a recombinant chimera of two highly conserved neutralizing epitopes from the L2 capsid protein inserted into L1. Our study demonstrated that the chimeric L1/L2 VLP is an effective vehicle for displaying two different L2 epitopes and can be used in a quantity equivalent to what is used in the licensed vaccines. Hence, using the chimeric L1/L2 VLP may be a more cost-effective approach for vaccine formulation than adding different VLPs for each HPV.


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