Structural Studies and Structure Activity Relationships for Novel Computationally Designed Non-nucleoside Inhibitors and Their Interactions With HIV-1 Reverse Transcriptase.

Reverse transcriptase (RT) from the human immunodeficiency virus continues to be an attractive drug target for antiretroviral therapy. June 2022 will commemorate the 30th anniversary of the first Human Immunodeficiency Virus (HIV) RT crystal structure complex that was solved with non-nucleoside reverse transcriptase inhibitor nevirapine. The release of this structure opened opportunities for designing many families of non-nucleoside reverse transcriptase inhibitors (NNRTIs).

Covalent Inhibition of Wild-Type HIV-1 Reverse Transcriptase Using a Fluorosulfate Warhead.

Covalent inhibitors of wild-type HIV-1 reverse transcriptase (CRTIs) are reported. Three compounds derived from catechol diether non-nucleoside inhibitors (NNRTIs) with addition of a fluorosulfate warhead are demonstrated to covalently modify Tyr181 of HIV-RT. X-ray crystal structures for complexes of the CRTIs with the enzyme are provided, which fully demonstrate the covalent attachment, and confirmation is provided by appropriate mass shifts in ESI-TOF mass spectra.

Post-Catalytic Complexes with Emtricitabine or Stavudine and HIV-1 Reverse Transcriptase Reveal New Mechanistic Insights for Nucleotide Incorporation and Drug Resistance.

Human immunodeficiency virus 1 (HIV-1) infection is a global health issue since neither a cure nor a vaccine is available. However, the highly active antiretroviral therapy (HAART) has improved the life expectancy for patients with acquired immunodeficiency syndrome (AIDS). Nucleoside reverse transcriptase inhibitors (NRTIs) are in almost all HAART and target reverse transcriptase (RT), an essential enzyme for the virus.

Structure-Guided Identification of DNMT3B Inhibitors.

Methyltransferase 3 beta (DNMT3B) inhibitors that interfere with cancer growth are emerging possibilities for treatment of melanoma. Herein we identify small molecule inhibitors of DNMT3B starting from a homology model based on a DNMT3A crystal structure. Virtual screening by docking led to purchase of 15 compounds, among which 5 were found to inhibit the activity of DNMT3B with IC values of 13-72 μM in a fluorogenic assay.

Structural insights into the recognition of nucleoside reverse transcriptase inhibitors by HIV-1 reverse transcriptase: First crystal structures with reverse transcriptase and the active triphosphate forms of lamivudine and emtricitabine.

The retrovirus HIV-1 has been a major health issue since its discovery in the early 80s. In 2017, over 37 million people were infected with HIV-1, of which 1.8 million were new infections that year.

Structural and pharmacological evaluation of a novel non-nucleoside reverse transcriptase inhibitor as a promising long acting nanoformulation for treating HIV.

Combination antiretroviral therapy (cART) has been proven effective in inhibiting human immunodeficiency virus type 1 (HIV-1) infection and has significantly improved the health outcomes in acquired immune deficiency syndrome (AIDS) patients. The therapeutic benefits of cART have been challenged because of the toxicity and emergence of drug-resistant HIV-1 strains along with lifelong patient compliance resulting in non-adherence. These issues also hinder the clinical benefits of non-nucleoside reverse transcriptase inhibitors (NNRTIs), which are one of the vital components of cART for the treatment of HIV-1 infection.

Mutational and structural studies uncover crucial amino acids determining activity and stability of 17β-HSD14.

17β-Hydroxysteroid dehydrogenase type 14 (17β-HSD14) catalyzes the conversion of highly active estrogens and androgens into their less active oxidized forms in presence of NAD as cofactor. The crystal structure of 17β-HSD14 has been determined, however, the role of individual amino acids likely involved in the enzymatic function remains poorly understood. Objective of this study was to further characterize the enzyme by site-directed mutagenesis considering five amino acids next to the catalytic center.

DRONE: Direct Tracking of DNA Cytidine Deamination and Other DNA Modifying Activities.

Enzymes that catalyze DNA modifying activities including cytidine deamination and cytosine methylation play important biological roles and have been implicated pathologically in diseases such as cancer. Here, we report Direct Resolution of ONE dalton difference (DRONE), an ultra high performance liquid chromatography (UHPLC)-based analytical method to track a single dalton change in the cytosine-to-uracil conversion catalyzed by the human apolipoprotein B m-RNA editing catalytic polypeptide-like 3 (APOBEC3) cytidine deaminases, implicated in cancer and antiviral defense. Additionally, we demonstrate broad applicability by tracking other important DNA modifications and assessing epigenetic enzyme inhibition.

Structure-based design and profiling of novel 17β-HSD14 inhibitors.

The human enzyme 17β-hydroxysteroid dehydrogenase 14 (17β-HSD14) oxidizes the hydroxyl group at position 17 of estradiol and 5-androstenediol using NAD as cofactor. However, the physiological role of the enzyme remains unclear. We recently described the first class of nonsteroidal inhibitors for this enzyme with compound 1 showing a high 17β-HSD14 inhibitory activity.

First Structure-Activity Relationship of 17β-Hydroxysteroid Dehydrogenase Type 14 Nonsteroidal Inhibitors and Crystal Structures in Complex with the Enzyme.

17β-HSD14 belongs to the SDR family and oxidizes the hydroxyl group at position 17 of estradiol and 5-androstenediol using NAD as cofactor. The goal of this study was to identify and optimize 17β-HSD14 nonsteroidal inhibitors as well as to disclose their structure-activity relationship. In a first screen, a library of 17β-HSD1 and 17β-HSD2 inhibitors, selected with respect to scaffold diversity, was tested for 17β-HSD14 inhibition.

New Insights into Human 17β-Hydroxysteroid Dehydrogenase Type 14: First Crystal Structures in Complex with a Steroidal Ligand and with a Potent Nonsteroidal Inhibitor.

17β-HSD14 is a SDR enzyme able to oxidize estradiol and 5-androstenediol using NAD(+). We determined the crystal structure of this human enzyme as the holo form and as ternary complexes with estrone and with the first potent, nonsteroidal inhibitor. The structures reveal a conical, rather large and lipophilic binding site and are the starting point for structure-based inhibitor design.