Inhibition of human endogenous retrovirus-K10 protease in cell-free and cell-based assays.
A full-length and C-terminally truncated version of human endogenous retrovirus (HERV)-K10 protease were expressed in Escherichia coli and purified to homogeneity. Both versions of the protease efficiently processed HERV-K10 Gag polyprotein substrate. HERV-K10 Gag was also cleaved by human immunodeficiency virus, type 1 (HIV-1) protease, although at different sites. To identify compounds that could inhibit protein processing dependent on the HERV-K10 protease, a series of cyclic ureas that had previously been shown to inhibit HIV-1 protease was tested. Several symmetric bisamides acted as very potent inhibitors of both the truncated and full-length form of HERV-K10 protease, in subnanomolar or nanomolar range, respectively. One of the cyclic ureas, SD146, can inhibit the processing of in vitro translated HERV-K10 Gag polyprotein substrate by HERV-K10 protease. In addition, in virus-like particles isolated from the teratocarcinoma cell line NCCIT, there is significant accumulation of Gag and Gag-Pol precursors upon treatment with SD146, suggesting the compound efficiently blocks HERV-K Gag processing in cells. This is the first report of an inhibitor able to block cell-associated processing of Gag polypeptides of an endogenous retrovirus.
Kuhelj
R
R
Department of Virology, Experimental Station, DuPont Pharmaceuticals, Wilmington, Delaware 19880, USA.
Rizzo
C J
CJ
Chang
C H
CH
Jadhav
P K
PK
Towler
E M
EM
Korant
B D
BD
D000595:Amino Acid Sequence; D000998:Antiviral Agents / Q000494:pharmacology; D001665:Binding Sites; D002474:Cell-Free System; D003001:Cloning, Molecular; D020077:Endogenous Retroviruses / Q000201:enzymology* / Q000235:genetics; D010450:Endopeptidases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli; D015683:Gene Products, gag / Q000378:metabolism; D016333:HIV Protease / Q000737:chemistry / Q000378:metabolism*; D017320:HIV Protease Inhibitors / Q000494:pharmacology*; D006801:Humans; D006860:Hydrogen Bonding; D008969:Molecular Sequence Data; D011480:Protease Inhibitors / Q000494:pharmacology*; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013379:Substrate Specificity; D013724:Teratoma; D014407:Tumor Cells, Cultured; D000085242:Viral Proteases
D000998:Antiviral Agents; D015683:Gene Products, gag; D017320:HIV Protease Inhibitors; D011480:Protease Inhibitors; D011994:Recombinant Proteins; D010450:Endopeptidases; D000085242:Viral Proteases; C429524:human endogenous retrovirus K10 protease; D016333:HIV Protease