Hyrtiosal, from the Marine Sponge Hyrtios erectus, Inhibits HIV‐1 Integrase Binding to Viral DNA by a New Inhibitor Binding Site

Abstract

HIV-1 integrase (IN) is composed of three domains, the N-terminal domain (NTD, residues 1-50), the catalytic core domain (CCD, residues 51-212), and the C-terminal domain (CTD, residues 213-288). All the three domains are required for the two known integration reactions. CCD contains the catalytic triad and is believed to bind viral DNA specifically, and CTD binds viral DNA in a nonspecific manner. As no clear evidence has confirmed the involvement of NTD in DNA binding directly, NTD has not been seriously considered and less is known about its function in viral replication. In the current work, using a SPR technology-based assay, the HIV-1 viral DNA was determined to bind directly to NTD with a K(D) value of 8.8 microM, suggesting that the process of preintegrated complex formation for HIV-1 IN might involve the direct interaction of NTD with viral DNA in addition to binding of viral DNA to the catalytic core domain and C-terminal domain. Moreover, such viral DNA/IN binding could be inhibited by the marine product hyrtiosal from the marine sponge Hyrtios erectus with an IC(50) of 9.60+/-0.86 microM. Molecular dynamic analysis correlated with a site-directed mutagenesis approach further revealed that such hyrtiosal-induced viral DNA/IN binding inhibition was caused by the fact that hyrtiosal could bind HIV-1 NTD at Ser17, Trp19, and Lys34. As hyrtiosal was recently discovered by us as a protein tyrosine phosphatase 1B (PTP1B) inhibitor,1 this work might also supply multiple-target information for this marine product, and the verified HIV-NTD/HIV-1 IN interaction model could have further implications for new HIV-1 IN inhibitor design and evaluation.

Natural products possessing protein tyrosine phosphatase 1B (PTP1B) inhibitory activity found in the last decades

“…Further research showed that 233 displayed potent activity for abolishing the retardation of AKT membrane translocation caused by PTP1B overexpression in CHO cells, dramatically enhanced the membrane translocation of the key glucose transporter Glut4 in PTP1B-overexpressed CHO cells, and effectively facilitated insulin inhibition of Smad2 activation. Moreover, hyrtiosal 233 was found to inhibit HIV-1 integrase from binding to viral DNA by a new inhibitor binding site [153] .…”

New Class of HIV-1 Integrase (IN) Inhibitors with a Dual Mode of Action

“…The N-terminal domain (NTD) of IN (residues 1-50) contains a zinc finger motif, HHCC, that mediates viral DNA binding and is essential for viral replication (19 -23). A natural product, hyrtiosal, has been shown to inhibit IN through direct binding to the NTD of IN (24). Such a targeting of the NTD of IN could disrupt Zn 2ϩ coordination by the zinc finger motif and have a detrimental effect on viral DNA binding, IN multimerization, and reverse transcription and/or integration.…”

Symmetrical 1-pyrrolidineacetamide showing anti-HIV activity through a new binding site on HIV-1 integrase1

“…In brief, Escherichia coli BL21(DE3) cells transformed with wild-type or mutated HIV-1 IN expression plasmids were grown at 37 °C in Lysogeny Broth (LB) medium containing 100 µg/mL ampicillin until the optical density at 600 nm reached 0.6−0. Competitive inhibition assay The compound's competitive inhibition assay against IN/viral DNA binding was performed by using the surface plasma resonance (SPR) biosensor technology-based Biacore 3000 system (Biacore AB, Uppsala, Sweden) as previously reported [19] . During the assay, a 21 bp 5´-biotinylated oligonucleotide (5´-GTGTGGAAAATCTCTAGGTGT-3´) hybridized with a non-biotinylated complementary oligonucleotide was immobilized on the streptavidin matrix-coated sensor chip (SA chip), and 200 nmol/L IN incubated with 0-0.2 mmol/L compounds for 1 h at 4 °C flowed over the chip surface.…”