ABSTRACT
Dengue is an important arboviral infectious disease for which there is currently no specific cure. We report gemini-like (geminoid) alkylated amphiphilic peptides containing lysines in combination with glycines or alanines (C15H31C(O)-Lys-(Gly or Ala)nLys-NHC16H33, shorthand notation C16-KXnK-C16 with X = A or G, and n = 0-2). The representatives with 1 or 2 Ala inhibit dengue protease and human furin, two serine proteases involved in dengue virus infection that have peptides with cationic amino acids as their preferred substrates, with IC50 values in the lower µM range. The geminoid C16-KAK-C16 combined inhibition of DENV2 protease (IC50 2.3 µM) with efficacy against replication of wildtype DENV2 in LLC-MK2 cells (EC50 4.1 µM) and an absence of toxicity. We conclude that the lysine-based geminoids have activity against dengue virus infection, which is based on their inhibition of the proteases involved in viral replication and are therefore promising leads to further developing antiviral therapeutics, not limited to dengue.
Subject(s)
Antiviral Agents , Dengue Virus , Furin , Protease Inhibitors , Virus Replication , Antiviral Agents/pharmacology , Dengue/drug therapy , Dengue Virus/drug effects , Dengue Virus/physiology , Furin/antagonists & inhibitors , Humans , Peptide Hydrolases , Peptides/pharmacology , Protease Inhibitors/pharmacology , Viral Nonstructural Proteins/metabolism , Virus Replication/drug effectsABSTRACT
Four-way junctions (4Hs) are important intermediates in DNA rearrangements such as genetic recombination. Under the influence of multivalent cations these molecules undergo a conformational change, from an extended planar form to a quasi-continuous stacked X-structure. Recently, a number of X-ray structures and a nuclear magnetic resonance (NMR) structure of 4Hs have been reported and in three of these the position of multivalent cations is revealed. These structures belong to two main families, characterized by the angle between the two co-axial stacked helices, which is either around +40 to +55 degrees or around -70 to -80 degrees. To investigate the role of metal-ion binding on the conformation of folded 4Hs we performed Brownian-dynamics simulations on the set of available structures. The simulations confirm the proposed metal-ion binding sites in the NMR structure and in one of the X-ray structures. Furthermore, the calculations suggest positions for metal-ion binding in the other X-ray structures. The results show a striking dependence of the ion density on the helical environment (B-helix or A-helix) and the structural family.
