Cryptococcosis is an invasive infection that accounts for 15% of AIDS-related fatalities. Still, treating cryptococcosis remains a significant challenge due to the poor availability of effective antifungal therapies and emergence of drug resistance. Interestingly, protease inhibitor components of antiretroviral therapy regimens have shown some clinical benefits in these opportunistic infections. We investigated Major aspartyl peptidase 1 (May1), a secreted Cryptococcus neoformans protease, as a possible target for the development of drugs that act against both fungal and retroviral aspartyl proteases. Here, we describe the biochemical characterization of May1, present its high-resolution X-ray structure, and provide its substrate specificity analysis. Through combinatorial screening of 11,520 compounds, we identified a potent inhibitor of May1 and HIV protease. This dual-specificity inhibitor exhibits antifungal activity in yeast culture, low cytotoxicity, and low off-target activity against host proteases and could thus serve as a lead compound for further development of May1 and HIV protease inhibitors.

• MeSH
• antifungální látky chemie   metabolismus   farmakologie   MeSH
• aspartátové proteasy antagonisté a inhibitory   genetika   metabolismus   MeSH
• Cryptococcus neoformans enzymologie   MeSH
• fungální proteiny antagonisté a inhibitory   genetika   metabolismus   MeSH
• HIV-proteasa chemie   metabolismus   MeSH
• HIV enzymologie   MeSH
• houby účinky léků   MeSH
• katalytická doména MeSH
• krystalografie rentgenová MeSH
• preklinické hodnocení léčiv MeSH
• rekombinantní proteiny biosyntéza   chemie   izolace a purifikace   MeSH
• simulace molekulární dynamiky MeSH
• substrátová specifita MeSH
• vazebná místa MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

High-pressure methods have become an interesting tool of investigation of structural stability of proteins. They are used to study protein unfolding, but dissociation of oligomeric proteins can be addressed this way, too. HIV-1 protease, although an interesting object of biophysical experiments, has not been studied at high pressure yet. In this study HIV-1 protease is investigated by high pressure (up to 600 MPa) fluorescence spectroscopy of either the inherent tryptophan residues or external 8-anilino-1-naphtalenesulfonic acid at 25°C. A fast concentration-dependent structural transition is detected that corresponds to the dimer-monomer equilibrium. This transition is followed by a slow concentration independent transition that can be assigned to the monomer unfolding. In the presence of a tight-binding inhibitor none of these transitions are observed, which confirms the stabilizing effect of inhibitor. High-pressure enzyme kinetics (up to 350 MPa) also reveals the stabilizing effect of substrate. Unfolding of the protease can thus proceed only from the monomeric state after dimer dissociation and is unfavourable at atmospheric pressure. Dimer-destabilizing effect of high pressure is caused by negative volume change of dimer dissociation of -32.5 mL/mol. It helps us to determine the atmospheric pressure dimerization constant of 0.92 μM. High-pressure methods thus enable the investigation of structural phenomena that are difficult or impossible to measure at atmospheric pressure.

• MeSH
• anilin-naftalen sulfonáty metabolismus   MeSH
• atmosférický tlak MeSH
• darunavir metabolismus   MeSH
• dimerizace MeSH
• fluorescenční spektrometrie MeSH
• HIV-proteasa chemie   metabolismus   MeSH
• inhibitory HIV-proteasy metabolismus   MeSH
• kinetika MeSH
• konformace proteinů MeSH
• lidé MeSH
• molekulární modely MeSH
• multimerizace proteinu MeSH
• sbalování proteinů * MeSH
• stabilita proteinů účinky léků   MeSH
• termodynamika MeSH
• tryptofan metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

HIV protease (PR) is required for proteolytic maturation in the late phase of HIV replication and represents a prime therapeutic target. The regulation and kinetics of viral polyprotein processing and maturation are currently not understood in detail. Here we design, synthesize, validate and apply a potent, photodegradable HIV PR inhibitor to achieve synchronized induction of proteolysis. The compound exhibits subnanomolar inhibition in vitro. Its photolabile moiety is released on light irradiation, reducing the inhibitory potential by 4 orders of magnitude. We determine the structure of the PR-inhibitor complex, analyze its photolytic products, and show that the enzymatic activity of inhibited PR can be fully restored on inhibitor photolysis. We also demonstrate that proteolysis of immature HIV particles produced in the presence of the inhibitor can be rapidly triggered by light enabling thus to analyze the timing, regulation and spatial requirements of viral processing in real time.

• MeSH
• aminokumariny chemická syntéza   farmakologie   MeSH
• časové faktory MeSH
• fotolýza MeSH
• HEK293 buňky MeSH
• HIV-1 účinky léků   fyziologie   účinky záření   MeSH
• HIV-proteasa chemie   metabolismus   MeSH
• inhibitory HIV-proteasy chemická syntéza   farmakologie   MeSH
• karbamáty chemická syntéza   farmakologie   MeSH
• kinetika MeSH
• lidé MeSH
• molekulární modely MeSH
• proteinové prekurzory antagonisté a inhibitory   chemie   metabolismus   MeSH
• proteolýza účinky léků   MeSH
• replikace viru MeSH
• světlo MeSH
• valin analogy a deriváty   chemická syntéza   farmakologie   MeSH
• vazba proteinů MeSH
• vazebná místa MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Insertions in the protease (PR) region of human immunodeficiency virus (HIV) represent an interesting mechanism of antiviral resistance against HIV PR inhibitors (PIs). Here, we demonstrate the improved ability of a phosphonate-containing experimental HIV PI, GS-8374, relative to that of other PIs, to effectively inhibit patient-derived recombinant HIV strains bearing PR insertions and numerous other mutations. We correlate enzyme inhibition with the catalytic activities of corresponding recombinant PRs in vitro and provide a biochemical and structural analysis of the PR-inhibitor complex.

• MeSH
• HIV infekce farmakoterapie   virologie   MeSH
• HIV-1 chemie   účinky léků   enzymologie   genetika   MeSH
• HIV-proteasa chemie   genetika   metabolismus   MeSH
• inhibitory HIV-proteasy chemie   farmakologie   MeSH
• inzerční mutageneze * MeSH
• krystalografie rentgenová MeSH
• lidé MeSH
• molekulární modely MeSH
• organofosfonáty analýza   MeSH
• sekvence aminokyselin MeSH
• vazebná místa MeSH
• virová léková rezistence MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

UNLABELLED: We report enzymologic, thermodynamic and structural analyses of a series of six clinically derived mutant HIV proteases (PR) resistant to darunavir. As many as 20 mutations in the resistant PRs decreased the binding affinity of darunavir by up to 13 000-fold, mostly because of a less favorable enthalpy of binding that was only partially compensated by the entropic contribution. X-ray structure analysis suggested that the drop in enthalpy of darunavir binding to resistant PR species was mostly the result of a decrease in the number of hydrogen bonds and a loosening of the fit between the inhibitor and the mutated enzymes. The favorable entropic contribution to darunavir binding to mutated PR variants correlated with a larger burial of the nonpolar solvent-accessible surface area upon inhibitor binding. We show that even very dramatic changes in the PR sequence leading to the loss of hydrogen bonds with the inhibitor could be partially compensated by the entropy contribution as a result of the burial of the larger nonpolar surface area of the mutated HIV PRs. DATABASE: Atomic coordinates and structure factors for the crystal structures PRwt-DRV and PRDRV2-DRV complex have been deposited in the Protein Data Bank under accession codes 4LL3 and 3TTP, respectively. STRUCTURED DIGITAL ABSTRACT: • PR and PR bind by x-ray crystallography (View interaction).

• MeSH
• HIV-proteasa chemie   genetika   metabolismus   MeSH
• inhibitory HIV-proteasy chemie   farmakologie   MeSH
• molekulární sekvence - údaje MeSH
• mutace * MeSH
• sekvence aminokyselin MeSH
• simulace molekulového dockingu * MeSH
• sulfonamidy chemie   farmakologie   MeSH
• termodynamika MeSH
• vazba proteinů MeSH
• virová léková rezistence genetika   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

HIV protease (PR) is a key target for antiviral drugs, and HIV protease inhibitors (PIs) are a prime example of successful structure-based drug design. PIs show clear therapeutic benefits, but their efficacy can be compromised by poor bioavailabilitity, unwanted side effects, and most importantly, development of antiviral drug resistance. Therefore, the quest for novel, highly active compounds with improved resistance profiles, better pharmacokinetic properties, and fewer adverse effects continues. In particular, the problem of cross-resistance could be circumvented by identifying novel compounds that show different binding modes to HIV PR than the current clinical inhibitors.

• MeSH
• cílená molekulární terapie metody   MeSH
• HIV-proteasa chemie   metabolismus   MeSH
• inhibitory HIV-proteasy chemická syntéza   chemie   MeSH
• katalytická doména MeSH
• lidé MeSH
• molekulární struktura MeSH
• peptidomimetika chemická syntéza   chemie   MeSH
• racionální návrh léčiv * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

HIV protease is a primary target for the design of virostatics. Screening of libraries of non-peptide low molecular weight compounds led to the identification of several new compounds that inhibit HIV PR in the low micromolar range. X-ray structure of the complex of one of them, a dibenzo[b,e][1,4]diazepinone derivative, showed that two molecules of the inhibitor bind to the PR active site. Covalent linkage of two molecules of such a compound by a two-carbon linker led to a decrease of the inhibition constant of the resulting compound by 3 orders of magnitude. Molecular modeling shows that these dimeric inhibitors form two crucial hydrogen bonds to the catalytic aspartates that are responsible for their improved activity compared to the monomeric parental building blocks. Dibenzo[b,e][1,4]diazepinone analogues might represent a potential new class of HIV PIs.

• MeSH
• benzodiazepiny chemie   MeSH
• HIV infekce farmakoterapie   enzymologie   virologie   MeSH
• HIV-1 účinky léků   MeSH
• HIV-proteasa chemie   metabolismus   MeSH
• inhibitory HIV-proteasy chemická syntéza   farmakologie   MeSH
• katalytická doména MeSH
• katalýza MeSH
• konformace proteinů MeSH
• krystalografie rentgenová MeSH
• lidé MeSH
• molekulární modely MeSH
• molekulární struktura MeSH
• peptidové fragmenty farmakologie   MeSH
• racionální návrh léčiv * MeSH
• vodíková vazba MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

During the last few decades, the treatment of HIV-infected patients by highly active antiretroviral therapy, including protease inhibitors (PIs), has become standard. Here, we present results of analysis of a patient-derived, multiresistant HIV-1 CRF02_AG recombinant strain with a highly mutated protease (PR) coding sequence, where up to 19 coding mutations have accumulated in the PR. The results of biochemical analysis in vitro showed that the patient-derived PR is highly resistant to most of the currently used PIs and that it also exhibits very poor catalytic activity. Determination of the crystal structure revealed prominent changes in the flap elbow region and S1/S1' active site subsites. While viral loads in the patient were found to be high, the insertion of the patient-derived PR into a HIV-1 subtype B backbone resulted in reduction of infectivity by 3 orders of magnitude. Fitness compensation was not achieved by elevated polymerase (Pol) expression, but the introduction of patient-derived gag and pol sequences in a CRF02_AG backbone rescued viral infectivity to near wild-type (wt) levels. The mutations that accumulated in the vicinity of the processing sites spanning the p2/NC, NC/p1, and p6pol/PR proteins lead to much more efficient hydrolysis of corresponding peptides by patient-derived PR in comparison to the wt enzyme. This indicates a very efficient coevolution of enzyme and substrate maintaining high viral loads in vivo under constant drug pressure.

• MeSH
• buněčné linie MeSH
• genové produkty gag - virus lidské imunodeficience genetika   MeSH
• genové produkty pol - virus lidské imunodeficience genetika   MeSH
• geny gag MeSH
• geny pol MeSH
• HEK293 buňky MeSH
• HIV infekce farmakoterapie   virologie   MeSH
• HIV-1 genetika   izolace a purifikace   fyziologie   MeSH
• HIV-proteasa chemie   genetika   metabolismus   MeSH
• inhibitory HIV-proteasy terapeutické užití   MeSH
• krystalografie rentgenová MeSH
• lidé MeSH
• molekulární sekvence - údaje MeSH
• mutace MeSH
• peptidové fragmenty genetika   MeSH
• virová léková rezistence genetika   MeSH
• virová nálož MeSH
• vysoce aktivní antiretrovirová terapie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH

HIV protease (HIV PR) is a primary target for anti-HIV drug design. We have previously identified and characterized substituted metallacarboranes as a new class of HIV protease inhibitors. In a structure-guided drug design effort, we connected the two cobalt bis(dicarbollide) clusters with a linker to substituted ammonium group and obtained a set of compounds based on a lead formula [H(2)N-(8-(C(2)H(4)O)(2)-1,2-C(2)B(9)H(10))(1',2'-C(2)B(9)H(11))-3,3'-Co)(2)]Na. We explored inhibition properties of these compounds with various substitutions, determined the HIV PR:inhibitor crystal structure, and computationally explored the conformational space of the linker. Our results prove the capacity of linker-substituted dual-cage cobalt bis(dicarbollides) as lead compounds for design of more potent inhibitors of HIV PR.

• MeSH
• elektrony MeSH
• HIV-1 enzymologie   účinky léků   MeSH
• HIV-proteasa chemie   metabolismus   MeSH
• inhibitory HIV-proteasy farmakologie   chemická syntéza   chemie   metabolismus   MeSH
• kobalt chemie   MeSH
• krystalografie rentgenová MeSH
• molekulární konformace MeSH
• molekulární modely MeSH
• racionální návrh léčiv MeSH
• sloučeniny boru chemická syntéza   chemie   farmakologie   metabolismus   MeSH
• uhlík chemie   MeSH
• Publikační typ
• práce podpořená grantem MeSH

Darunavir is the most recently approved human immunodeficiency virus (HIV) protease (PR) inhibitor (PI) and is active against many HIV type 1 PR variants resistant to earlier-generation PIs. Darunavir shows a high genetic barrier to resistance development, and virus strains with lower sensitivity to darunavir have a higher number of PI resistance-associated mutations than viruses resistant to other PIs. In this work, we have enzymologically and structurally characterized a number of highly mutated clinically derived PRs with high levels of phenotypic resistance to darunavir. With 18 to 21 amino acid residue changes, the PR variants studied in this work are the most highly mutated HIV PR species ever studied by means of enzyme kinetics and X-ray crystallography. The recombinant proteins showed major defects in substrate binding, while the substrate turnover was less affected. Remarkably, the overall catalytic efficiency of the recombinant PRs (5% that of the wild-type enzyme) is still sufficient to support polyprotein processing and particle maturation in the corresponding viruses. The X-ray structures of drug-resistant PRs complexed with darunavir suggest that the impaired inhibitor binding could be explained by change in the PR-inhibitor hydrogen bond pattern in the P2' binding pocket due to a substantial shift of the aminophenyl moiety of the inhibitor. Recombinant virus phenotypic characterization, enzyme kinetics, and X-ray structural analysis thus help to explain darunavir resistance development in HIV-positive patients.

• MeSH
• genové produkty env - virus lidské imunodeficience metabolismus   MeSH
• genové produkty gag - virus lidské imunodeficience metabolismus   MeSH
• HIV infekce virologie   MeSH
• HIV-1 izolace a purifikace   účinky léků   MeSH
• HIV-proteasa genetika   chemie   metabolismus   MeSH
• inhibitory HIV-proteasy farmakologie   MeSH
• krystalografie rentgenová MeSH
• lidé MeSH
• missense mutace MeSH
• molekulární modely MeSH
• molekulární sekvence - údaje MeSH
• mutační analýza DNA MeSH
• polyproteiny metabolismus   MeSH
• sekvence aminokyselin MeSH
• substituce aminokyselin MeSH
• sulfonamidy farmakologie   MeSH
• terciární struktura proteinů MeSH
• vazba proteinů MeSH
• vazebná místa MeSH
• virová léková rezistence MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• práce podpořená grantem MeSH