Fusion of protegrin-1 and plectasin to MAP30 shows significant inhibition activity against dengue virus replication

PLoS One. 2014 Apr 10;9(4):e94561. doi: 10.1371/journal.pone.0094561. eCollection 2014.

Abstract

Dengue virus (DENV) broadly disseminates in tropical and sub-tropical countries and there are no vaccine or anti-dengue drugs available. DENV outbreaks cause serious economic burden due to infection complications that requires special medical care and hospitalization. This study presents a new strategy for inexpensive production of anti-DENV peptide-fusion protein to prevent and/or treat DENV infection. Antiviral cationic peptides protegrin-1 (PG1) and plectasin (PLSN) were fused with MAP30 protein to produce recombinant antiviral peptide-fusion protein (PG1-MAP30-PLSN) as inclusion bodies in E. coli. High yield production of PG1-MAP30-PLSN protein was achieved by solubilization of inclusion bodies in alkaline buffer followed by the application of appropriate refolding techniques. Antiviral PG1-MAP30-PLSN protein considerably inhibited DENV protease (NS2B-NS3pro) with half-maximal inhibitory concentration (IC50) 0.5±0.1 μM. The real-time proliferation assay (RTCA) and the end-point proliferation assay (MTT assay) showed that the maximal-nontoxic dose of the peptide-fusion protein against Vero cells is approximately 0.67±0.2 μM. The cell-based assays showed considerable inhibition of the peptide-fusion protein against binding and proliferating stages of DENV2 into the target cells. The peptide-fusion protein protected DENV2-challeged mice with 100% of survival at the dose of 50 mg/kg. In conclusion, producing recombinant antiviral peptide-fusion protein by combining short antiviral peptide with a central protein owning similar activity could be useful to minimize the overall cost of short peptide production and take advantage of its synergistic antiviral activities.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antimicrobial Cationic Peptides / genetics*
  • Antimicrobial Cationic Peptides / metabolism
  • Chlorocebus aethiops
  • Dengue / drug therapy*
  • Dengue / mortality
  • Dengue / virology
  • Dengue Virus / drug effects
  • Dengue Virus / enzymology
  • Dengue Virus / growth & development
  • Dose-Response Relationship, Drug
  • Escherichia coli / genetics
  • Escherichia coli / metabolism
  • Female
  • Gene Expression
  • Inclusion Bodies / chemistry
  • Male
  • Mice
  • Mice, Inbred ICR
  • Molecular Sequence Data
  • Peptides / genetics*
  • Peptides / metabolism
  • Protein Refolding
  • Recombinant Fusion Proteins / biosynthesis
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / pharmacology*
  • Ribosome Inactivating Proteins, Type 2 / genetics*
  • Ribosome Inactivating Proteins, Type 2 / metabolism
  • Serine Endopeptidases / metabolism
  • Survival Analysis
  • Vero Cells
  • Viral Nonstructural Proteins / antagonists & inhibitors
  • Viral Nonstructural Proteins / metabolism

Substances

  • Antimicrobial Cationic Peptides
  • MAP30 protein, Momordica charantia
  • NS2B protein, flavivirus
  • Peptides
  • Recombinant Fusion Proteins
  • Ribosome Inactivating Proteins, Type 2
  • Viral Nonstructural Proteins
  • plectasin
  • protegrin-1
  • NS3 protease, dengue virus
  • Serine Endopeptidases

Grants and funding

This project was funded by the University of Malaya and Ministry of Science, Technology and Innovation (ERGS Grant ER016-2013A). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.