title: Protegrin-1 inhibits dengue NS2B-NS3 serine protease and viral replication in MK2 cells.
abstract: Dengue diseases have an economic as well as social burden worldwide. In this study, the antiviral activity of protegrin-1 (PG-1, RGGRLCYCRRRFCVCVGR) peptide towards dengue NS2B-NS3pro and viral replication in Rhesus monkey kidney (MK2) cells was investigated. The peptide PG-1 was synthesized by solid-phase peptide synthesis, and disulphide bonds formation followed by peptide purification was confirmed by LC-MS and RPHPLC. Dengue NS2B-NS3pro was produced as a single-chain recombinant protein in E. coli. The NS2B-NS3pro assay was carried out by measuring the florescence emission of catalyzed substrate. Real-time PCR was used to evaluate the inhibition potential of PG-1 towards dengue serotype-2 (DENV-2) replication in MK2 cells. The results showed that PG-1 inhibited dengue NS2B-NS3pro at IC(50) of 11.7 μM. The graded concentrations of PG-1 at nontoxic range were able to reduce viral replication significantly (P < 0.001) at 24, 48, and 72 hrs after viral infection. However, the percentage of inhibition was significantly (P < 0.01) higher at 24 hrs compared to 48 and 72 hrs. These data show promising therapeutic potential of PG-1 against dengue infection, hence it warrants further analysis and improvement of the peptide features as a prospective starting point for consideration in designing attractive dengue virus inhibitors.
authors.affiliation: Department of Molecular Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia. molec.genetics@gmail.com
authors.forename: Hussin A
authors.initials: HA
authors.lastname: Rothan
authors.forename: Ammar Y
authors.initials: AY
authors.lastname: Abdulrahman
authors.forename: Pottayil G
authors.initials: PG
authors.lastname: Sasikumer
authors.forename: Shatrah
authors.initials: S
authors.lastname: Othman
authors.forename: Noorsaadah Abd
authors.initials: NA
authors.lastname: Rahman
authors.forename: Rohana
authors.initials: R
authors.lastname: Yusof
mesh_terms: D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000494:pharmacology*; D002460:Cell Line; D003716:Dengue Virus / Q000187:drug effects* / Q000201:enzymology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007668:Kidney / Q000821:virology*; D008253:Macaca mulatta; D012697:Serine Endopeptidases / Q000378:metabolism*; D017361:Viral Nonstructural Proteins / Q000378:metabolism*; D014779:Virus Replication / Q000187:drug effects* / Q000502:physiology*; D000085242:Viral Proteases
chemical_list: D023181:Antimicrobial Cationic Peptides; D004791:Enzyme Inhibitors; D012697:Serine Endopeptidases; D017361:Viral Nonstructural Proteins; C080102:NS2B protein, flavivirus; C094880:protegrin-1; C504449:NS3 protease, dengue virus; D000085242:Viral Proteases