Addition of a C-terminal cysteine improves the anti-herpes simplex virus activity of a peptide containing the human immunodeficiency virus type 1 TAT protein transduction domain.
Previous studies have shown that peptides containing the protein transduction domain (PTD) of the human immunodeficiency virus tat protein (GRKKRRQRRR) were effective inhibitors of herpes simplex virus type 1 (HSV-1) entry (H. Bultmann and C. R. Brandt, J. Biol. Chem. 277:36018-36023, 2002). We now show that the addition of a single cysteine residue to the C terminus of the TAT PTD (TAT-C peptide) improves the antiviral activity against HSV-1 and HSV-2. The principle effect of adding the cysteine was to enable the peptide to inactivate virions and to induce a state of resistance to infection in cells pretreated with peptide. The TAT-C peptide acted extracellularly, immediately blocked entry of adsorbed virus, prevented VP16 translocation to the nucleus, and blocked syncytium formation and cell-cell spread. Thus, TAT-C peptides are fusion inhibitors. The induction of the resistance of cells to infection was rapid, recovered with a half-life of 5 to 6 h, and could be reinduced by peptide treatment. TAT-C bound to heparan sulfate but was a poor competitor for viral attachment. The antiviral activity depended on the net positive charge of the peptide but not on chirality, and a free sulfhydryl group was not essential for antiviral activity because TAT-C dimers were at least as effective as monomers. The unique combination of antiviral activities and low toxicity combine to make TAT-C a strong candidate for further development as a drug to block HSV infection.
Bultmann
Hermann
H
Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, 6630 Medical Sciences Center, Madison, WI 53706, USA.
Teuton
Jeremy
J
Brandt
Curtis R
CR
D000327:Adsorption; D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D002522:Chlorocebus aethiops; D003545:Cysteine; D019281:Dimerization; D004305:Dose-Response Relationship, Drug; D015696:Gene Products, tat / Q000737:chemistry / Q000494:pharmacology*; D015497:HIV-1 / Q000737:chemistry*; D018259:Herpesvirus 1, Human / Q000187:drug effects* / Q000502:physiology; D018258:Herpesvirus 2, Human / Q000187:drug effects; D017434:Protein Structure, Tertiary; D013329:Structure-Activity Relationship; D014709:Vero Cells; D014771:Virion / Q000187:drug effects; D054322:tat Gene Products, Human Immunodeficiency Virus
D000998:Antiviral Agents; D015696:Gene Products, tat; D054322:tat Gene Products, Human Immunodeficiency Virus; D003545:Cysteine