Structural and thermodynamic basis of the inhibition ofLeishmania majorfarnesyl diphosphate synthase by nitrogen-containing bisphosphonates (original) (raw)

3-D QSAR Investigations of the Inhibition of Leishmania major Farnesyl Pyrophosphate Synthase by Bisphosphonates

Journal of Medicinal Chemistry, 2003

We report the activities of 62 bisphosphonates as inhibitors of the Leishmania major mevalonate/isoprene biosynthesis pathway enzyme, farnesyl pyrophosphate synthase. The compounds investigated exhibit activities (IC 50 values) ranging from ∼100 nM to ∼80 µM (corresponding to K i values as low as 10 nM). The most active compounds were found to be zoledronate (whose single-crystal X-ray structure is reported), pyridinyl-ethane-1-hydroxy-1,1bisphosphonates or picolyl aminomethylene bisphosphonates. However, N-alicyclic aminomethylene bisphosphonates, such as incadronate (N-cycloheptyl aminomethylene bisphosphonate), as well as aliphatic aminomethylene bisphosphonates containing short (n) 4, 5) alkyl chains, were also active, with IC 50 values in the 200-1700 nM range (corresponding to K i values of ∼20-170 nM). Bisphosphonates containing longer or multiple (N,N-) alkyl substitutions were inactive, as were aromatic species lacking an o-or m-nitrogen atom in the ring, or possessing multiple halogen substitutions or a p-amino group. To put these observations on a more quantitative structural basis, we used three-dimensional quantitative structure-activity relationship techniques: comparative molecular field analysis (CoMFA) and comparative molecular similarity index analysis (CoMSIA), to investigate which structural features correlated with high activity. Training set results (N) 62 compounds) yielded good correlations with each technique (R 2) 0.87 and 0.88, respectively), and were further validated by using a training/test set approach. Test set results (N) 24 compounds) indicated that IC 50 values could be predicted within factors of 2.9 and 2.7 for the CoMFA and CoMSIA methods, respectively. The CoMSIA fields indicated that a positive charge in the bisphosphonate side chain and a hydrophobic feature contributed significantly to activity. Overall, these results are of general interest since they represent the first detailed quantitative structure-activity relationship study of the inhibition of an expressed farnesyl pyrophosphate synthase enzyme by bisphosphonate inhibitors and that the activity of these inhibitors can be predicted within about a factor of 3 by using 3D-QSAR techniques.

Pyridinium-1-yl Bisphosphonates Are Potent Inhibitors of Farnesyl Diphosphate Synthase and Bone Resorption

Journal of Medicinal Chemistry, 2005

We report the design, synthesis and testing of a series of novel bisphosphonates, pyridinium-1-yl-hydroxy-bisphosphonates, based on the results of comparative molecular similarity indices analysis and pharmacophore modeling studies of farnesyl diphosphate synthase (FPPS) inhibition, human Vγ2Vδ2 T cell activation and bone resorption inhibition. The most potent molecules have high activity against an expressed FPPS from Leishmania major, in Dictyostelium discoideum growth inhibition, in γδ T cell activation and in an in vitro bone resorption assay. As such, they represent useful new leads for the discovery of new bone resorption, antiinfective and anticancer drugs.

Phosphonate and Bisphosphonate Inhibitors of Farnesyl Pyrophosphate Synthases: A Structure-Guided Perspective

Frontiers in Chemistry, 2021

Phosphonates and bisphosphonates have proven their pharmacological utility as inhibitors of enzymes that metabolize phosphate and pyrophosphate substrates. The blockbuster class of drugs nitrogen-containing bisphosphonates represent one of the best-known examples. Widely used to treat bone-resorption disorders, these drugs work by inhibiting the enzyme farnesyl pyrophosphate synthase. Playing a key role in the isoprenoid biosynthetic pathway, this enzyme is also a potential anticancer target. Here, we provide a comprehensive overview of the research efforts to identify new inhibitors of farnesyl pyrophosphate synthase for various therapeutic applications. While the majority of these efforts have been directed against the human enzyme, some have been targeted on its homologs from other organisms, such as protozoan parasites and insects. Our particular focus is on the structures of the target enzymes and how the structural information has guided the drug discovery efforts.

Inhibition of Geranylgeranyl Diphosphate Synthase by Bisphosphonates and Diphosphates: A Potential Route to New Bone Antiresorption and Antiparasitic Agents

Journal of Medicinal Chemistry, 2002

We report the X-ray structures of several bisphosphonate inhibitors of geranylgeranyl diphosphate synthase, a target for anticancer drugs. Bisphosphonates containing unbranched side chains bind to either the farnesyl diphosphate (FPP) substrate site, the geranylgeranyl diphosphate (GGPP) product site, and in one case, both sites, with the bisphosphonate moiety interacting with 3 Mg 2+ that occupy the same position as found in FPP synthase. However, each of three "V-shaped" bisphosphonates bind to both the FPP and GGPP sites. Using the Glide program, we reproduced the binding modes of 10 bisphosphonates with an rms error of 1.3 Å. Activities of the bisphosphonates in GGPPS inhibition were predicted with an overall error of 2× by using a comparative molecular similarity analysis based on a docked-structure alignment. These results show that some GGPPS inhibitors can occupy both substrate and product site and that binding modes as well as activity can be accurately predicted, facilitating the further development of GGPPS inhibitors as anticancer agents. † Crystal structure coordinates have been deposited in the Protein Data Bank and will be released upon publication (2z4w, 2z4z, 2z78, 2z4x, 2z4y, 2z50, 2z52, 2z4v, 2z71).

Molecular interactions of nitrogen-containing bisphosphonates within farnesyl diphosphate synthase

Journal of Organometallic Chemistry, 2005

Bisphosphonates, known for their effectiveness in the treatment of osteoporosis, inhibit bone resorption via mechanisms that involve binding to bone mineral and cellular effects on osteoclasts. The major molecular target of nitrogen-containing bisphosphonates (N-BPs) in osteoclasts is farnesyl diphosphate synthase (FPPS). N-BPs likely inhibit this enzyme by mimicking one or more of the natural isoprenoid lipid substrates (GPP/DMAPP and IPP) but the mode of inhibition is not established. The active site of FPPS comprises a subsite for each substrate. Kinetic studies with recombinant human FPPS indicate that both potent (risedronate) and weak (NE-58051) enzyme inhibitors compete with GPP for binding to FPPS, however, binding to this site does not completely explain the difference in potency of the two inhibitors, suggesting that a second binding site may also be a target of bisphosphonate inhibition. Using the docking software suite Autodock, we explored a dual inhibitor binding mode for recombinant human FPPS. Experimental support for dual binding is suggested by Dixon plots for the inhibitors. N-BPs may inhibit by binding to both the GPP and a second site with differences in potency at least partly arising from inhibition at the second site.

Bisphosphonate-Based Molecules as Potential New Antiparasitic Drugs

Molecules

Neglected tropical diseases such as Chagas disease and leishmaniasis affect millions of people around the world. Both diseases affect various parts of the globe and drugs traditionally used in therapy against these diseases have limitations, especially with regard to low efficacy and high toxicity. In this context, the class of bisphosphonate-based compounds has made significant advances regarding the chemical synthesis process as well as the pharmacological properties attributed to these compounds. Among this spectrum of pharmacological activity, bisphosphonate compounds with antiparasitic activity stand out, especially in the treatment of Chagas disease and leishmaniasis caused by Trypanosoma cruzi and Leishmania spp., respectively. Some bisphosphonate compounds can inhibit the mevalonate pathway, an essential metabolic pathway, by interfering with the synthesis of ergosterol, a sterol responsible for the growth and viability of these parasites. Therefore, this review aims to pres...

Binding of nitrogen-containing bisphosphonates (N-BPs) to the Trypanosoma cruzi farnesyl diphosphate synthase homodimer

Proteins: Structure, Function, and Bioinformatics, 2010

Bisphosphonates (BPs) are a class of compounds that have been used extensively in the treatment of osteoporosis and malignancy-related hypercalcemia. Some of these compounds act through inhibition of farnesyl diphosphate synthase (FPPS), a key enzyme in the synthesis of isoprenoids. Recently, nitrogen-containing bisphosphonates (N-BPs) used in bone resorption therapy have been shown to be active against Trypanosoma cruzi, the parasite that causes American trypanosomiasis (Chagas disease), suggesting that they may be used as anti-trypanosomal agents. The crystal structures of TcFPPS in complex with substrate (isopentenyl diphosphate, IPP) and five N-BP inhibitors show that the C-1 hydroxyl and the nitrogen-containing groups of the inhibitors alter the binding of IPP and the conformation of two TcFPPS residues, Tyr94 and Gln167. Isothermal titration calorimetry experiments suggest that binding of the first N-BPs to the homodimeric TcFPPS changes the binding properties of the second site. This mechanism of binding of N-BPs to TcFPPS is different to that reported for the binding of the same compounds to human FPPS.

Lipophilic Bisphosphonates as Dual Farnesyl/Geranylgeranyl Diphosphate Synthase Inhibitors: An X-ray and NMR Investigation

Journal of the American Chemical Society, 2009

Considerable effort has focused on the development of selective protein farnesyl transferase (FTase) and protein geranylgeranyl transferase (GGTase) inhibitors as cancer chemotherapeutics. Here, we report a new strategy for anti-cancer therapeutic agents involving inhibition of farnesyl diphosphate synthase (FPPS) and geranylgeranyl diphosphate synthase (GGPPS), the two enzymes upstream of FTase and GGTase, by lipophilic bisphosphonates. Due to dual site targeting and decreased polarity, the compounds have activities far greater than do current bisphosphonate drugs in inhibiting tumor cell growth and invasiveness, both in vitro and in vivo. We explore how these compounds inhibit cell growth, how cell activity can be predicted based on enzyme inhibition data, and, using x-ray diffraction, solid state NMR and isothermal titration calorimetry, we show how these compounds bind to FPPS and/or GGPPS.

Inhibition of Geranylgeranyl Diphosphate Synthase by Bisphosphonates: A Crystallographic and Computational Investigation

Journal of Medicinal Chemistry, 2008

We report the X-ray structures of several bisphosphonate inhibitors of geranylgeranyl diphosphate synthase, a target for anticancer drugs. Bisphosphonates containing unbranched side chains bind to either the farnesyl diphosphate (FPP) substrate site, the geranylgeranyl diphosphate (GGPP) product site, and in one case, both sites, with the bisphosphonate moiety interacting with 3 Mg 2+ that occupy the same position as found in FPP synthase. However, each of three "V-shaped" bisphosphonates bind to both the FPP and GGPP sites. Using the Glide program, we reproduced the binding modes of 10 bisphosphonates with an rms error of 1.3 Å. Activities of the bisphosphonates in GGPPS inhibition were predicted with an overall error of 2× by using a comparative molecular similarity analysis based on a docked-structure alignment. These results show that some GGPPS inhibitors can occupy both substrate and product site and that binding modes as well as activity can be accurately predicted, facilitating the further development of GGPPS inhibitors as anticancer agents. † Crystal structure coordinates have been deposited in the Protein Data Bank and will be released upon publication (2z4w, 2z4z, 2z78, 2z4x, 2z4y, 2z50, 2z52, 2z4v, 2z71).

Design, Synthesis, Calorimetry, and Crystallographic Analysis of 2-Alkylaminoethyl-1,1-bisphosphonates as Inhibitors of Trypanosoma cruzi Farnesyl Diphosphate Synthase

Journal of Medicinal Chemistry, 2012

Linear 2-alkylaminoethyl-1,1-bisphosphonates are effective agents against proliferation of Trypanosoma cruzi-the etiologic agent of American trypanosomiasis (Chagas disease)-exhibiting IC 50 values in the nanomolar range against the parasites. This activity is associated with inhibition at the low nanomolar level of the T. cruzi farnesyl diphosphate synthase (TcFPPS). X-ray structures and thermodynamic data of the complexes TcFPPS with five compounds of this family show that the inhibitors bind to the allylic site of the enzyme with their alkyl chain occupying the cavity that binds the isoprenoid chain of the substrate. The compounds bind to TcFPPS with unfavorable enthalpy compensated by a favorable entropy that results from a delicate balance between two opposing effects: the loss of conformational entropy due to freezing of single bond rotations, and the favorable burial of the hydrophobic alkyl chains. The data suggest that introduction of strategically placed double bonds and methyl branches should increase affinity substantially.