Bisphosphonate Inhibition of the Exopolyphosphatase Activity of the Trypanosoma brucei Soluble Vacuolar Pyrophosphatase
摘要:
Trypanosoma brucei, the causative agent of African trypanosomiasis, contains a soluble, vacuolar pyrophosphatase, TbVSP1, not present in humans, which is essential for the growth of bloodstream forms in their mammalian host. Here, we report the inhibition of a recombinant TbVSP1 expressed in Escherichia coli by a panel of 81 bisphosphonates. The IC50 values were found to vary from similar to 2 to 850 mu M. We then used 3D QSAR (comparative molecular field and comparative molecular similarity index; CoMFA and CoMSIA) methods to analyze the enzyme inhibition results. The R-2 values for the experimental versus the QSAR-predicted activities were 0.78 or 0.61 for CoMFA and 0.79 or 0.68 for CoMSIA, for two different alignments. The root-mean-square (rms) pIC(50) error for the best CoMFA model was 0.41 for five test sets of five activity predictions, which translates to a factor of similar to 2.6 error in IC50 prediction. For CoMSIA, the rms pIC(50) error and error factors were 0.35 and 2.2, respectively. In general, the most active compounds contained both a single aromatic ring and a hydrogen bond donor feature. Thirteen of the more potent compounds were then tested in vivo in a mouse model of T. brucei infection. The most active compound in vivo provided a 40% protection from death with no apparent side effects, suggesting that further development of such compounds may be of interest.
Arylamino methylene bisphosphonate derivatives as bone seeking matrix metalloproteinase inhibitors
摘要:
The complexity of matrix metalloproteinase inhibitors (MMPIs) design derives from the difficulty in carefully addressing their inhibitory activity towards the MMP isoforms involved in many pathological conditions. In particular, specific metalloproteinases, such as MMP-2 and MMP-9, are key regulators of the 'vicious cycle' occurring between tumor metastases growth and bone remodeling. In an attempt to devise new approaches to selective inhibitor derivatives, we describe novel bisphosphonate bone seeking MMP inhibitors (BP-MMPIs), capable to be selectively targeted and to overcome undesired side effects of broad spectrum MMPIs.In vitro activity (IC50 values) for each inhibitor was determined against MMP-2, -8, -9 and -14, because of their relevant role in skeletal development and renewal. The results show that BP-MMPIs reached IC50 values of enzymatic inhibition in the low micromolar range. Computational studies, used to rationalize some trends in the observed inhibitory profiles, suggest a possible differential binding mode in MMP-2 that explains the selective inhibition of this isoform.In addition, survival assay was conducted on J774 cell line, a well known model system used to evaluate the structure-activity relationship of BPs for inhibiting bone resorption. The resulting data, confirming the specific activity of BP-MMPIs, and their additional proved propensity to bind hydroxyapatite powder in vitro, suggest a potential use of BP-MMPIs in skeletal malignancies. (C) 2013 Elsevier Ltd. All rights reserved.
Design and Synthesis of Active Site Inhibitors of the Human Farnesyl Pyrophosphate Synthase: Apoptosis and Inhibition of ERK Phosphorylation in Multiple Myeloma Cells
作者:Yih-Shyan Lin、Jaeok Park、Joris W. De Schutter、Xian Fang Huang、Albert M. Berghuis、Michael Sebag、Youla S. Tsantrizos
DOI:10.1021/jm201657x
日期:2012.4.12
Human farnesyl pyrophosphate synthase (hFPPS) controls intracellular levels of FPP and post-translational prenylation of small GTPase proteins, which are essential for cell signaling and cell proliferation. Clinical investigations provide evidence that N-BP inhibitors of hFPPS are disease modifying agents that improve survival of multiple myeloma (MM) patients via mechanisms unrelated to their skeletal effects. A new series of N-BPs was designed that interact with a larger portion of the GPP subpocket, as compared to the current therapeutic drugs, and rigidify the (KRRK367)-K-364 tail of hFPPS in the closed conformation in the absence of IPP. An analogue of this series was used to demonstrate inhibition of the intended biological target, resulting in apoptosis and down-regulation of ERK phosphorylation in human MM cell lines.
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作者:V. I. Krutikov、A. V. Erkin、P. A. Pautov、M. M. Zolotukhina
DOI:10.1023/a:1024775501781
日期:——
A series of substituted aminomethylenebisphosphonates is prepared by reaction of dialkyl hydrogen phosphites with triethyl orthoformate and corresponding heteryl- or arylamine. The determining factor in the formation of the target products is appearance of an intermediate associate between the ortho ester and amine. The rate and selectivity of the process can be increased by using a nonpolar solvent to stabilize the transition state of the reaction. Crown ether catalysis increases the selectivity of the process by 10-20%. The synthesized aminomethylenebisphosphonates whose structure was established by NMR spectroscopy exhibit a moderate antibacterial and anticholinesterase activity.