Design of a Potent d -Peptide HIV-1 Entry Inhibitor with a Strong Barrier to Resistance

Abstract

The HIV gp41 N-trimer pocket region is an ideal viral target because it is extracellular, highly conserved, and essential for viral entry. Here, we report on the design of a pocket-specific D-peptide, PIE12-trimer, that is extraordinarily elusive to resistance and characterize its inhibitory and structural properties. D-Peptides (peptides composed of D-amino acids) are promising therapeutic agents due to their insensitivity to protease degradation. PIE12-trimer was designed using structure-guided mirror-image phage display and linker optimization and is the first D-peptide HIV entry inhibitor with the breadth and potency required for clinical use. PIE12-trimer has an ultrahigh affinity for the gp41 pocket, providing it with a reserve of binding energy (resistance capacitor) that yields a dramatically improved resistance profile compared to those of other fusion inhibitors. These results demonstrate that the gp41 pocket is an ideal drug target and establish PIE12-trimer as a leading anti-HIV antiviral candidate.

One Percent Tenofovir Applied Topically to Humanized BLT Mice and Used According to the CAPRISA 004 Experimental Design Demonstrates Partial Protection from Vaginal HIV Infection, Validating the BLT Model for Evaluation of New Microbicide Candidates

“…4). Prior to selection for in vivo efficacy evaluation here, each inhibitor was shown to efficiently inhibit HIV in vitro (3,5,39,43,50,52,54,56). Our experimental approach for testing these six inhibitors was a single dose of the product administered prior to exposure rather than the two doses of drug administered within 24 h as used in CAPRISA 004 (1).…”

“…PIE12-Trimer is a D-peptide that binds to a conserved pocket on the surface of trimeric gp41. PIE12-Trimer blocks the final stages of the fusion process between the virion and cell membranes (54). TC247 is a thioester compound zinc finger inhibitor that ejects zinc ions from the two HIV nucleocapsid zinc finger loops (32).…”

Broad Antiviral Activity and Crystal Structure of HIV-1 Fusion Inhibitor Sifuvirtide

“…The results from the single cycle infection assays are presented in Table 2. Compared with T20, SFT displayed more potent inhibitory activity, with mean IC 50 (17)(18)(19)(20)(21). Our previous studies demonstrated that SFT possessed efficient potency to inhibit HIV-1 variants that carry single or double T20-resistant mutations (e.g.…”

“…Among them, T20 (Enfuvirtide, Fuzeon) has been approved for clinical use as the first member of a new class of anti-HIV drugs, HIV fusion inhibitors (9,16,17). This peptide drug can suppress replication of HIV variants with multidrug resistance to reverse transcriptase and protease inhibitors; however, it also easily induces resistance in both clinical settings and laboratory studies (17)(18)(19)(20)(21).…”

Synthesis and folding of a mirror-image enzyme reveals ambidextrous chaperone activity

“…Due to great interest in mirror-image proteins as targets for drug discovery (6,7,18,19) and mirror-image synthetic biology (20,21), we were intrigued by the possibility that natural (L-) GroEL/ES could assist in the folding of D-proteins. Thus, we synthesized a D-version of a substrate protein and evaluated its folding by GroEL/ES.…”