共查询到20条相似文献,搜索用时 15 毫秒
1.
Dhar TG Shen Z Gu HH Chen P Norris D Watterson SH Ballentine SK Fleener CA Rouleau KA Barrish JC Townsend R Hollenbaugh DL Iwanowicz EJ 《Bioorganic & medicinal chemistry letters》2003,13(20):3557-3560
A series of novel small molecule inhibitors of inosine monophosphate dehydrogenase (IMPDH), based upon a 3-cyanoindole core, were explored. IMPDH catalyzes the rate determining step in guanine nucleotide biosynthesis and is a target for anticancer, immunosuppressive and antiviral therapy. The synthesis and the structure-activity relationships (SAR), derived from in vitro studies, for this new series of inhibitors is given. 相似文献
2.
Buckley GM Davies N Dyke HJ Gilbert PJ Hannah DR Haughan AF Hunt CA Pitt WR Profit RH Ray NC Richard MD Sharpe A Taylor AJ Whitworth JM Williams SC 《Bioorganic & medicinal chemistry letters》2005,15(3):751-754
The development of a series of novel quinazolinethiones and quinazolinediones as inhibitors of inosine monophosphate dehydrogenase (IMPDH) is described. The synthesis, in vitro inhibitory values for IMPDH II and in vitro inhibitory value for PBMC proliferation are discussed. 相似文献
3.
Inosine 5′-monophosphate dehydrogenase (IMPDH, EC 1.1.1.205) catalyzes a crucial step in guanine nucleotide biosynthesis, thereby governing cell proliferation. In contrast to mammalian IMPDHs, microbial IMPDHs are relatively less explored as potential targets for antimicrobial drug discovery. In continuation with our previous work, here we report the discovery of moderately potent and highly selective Helicobacter pylori IMPDH (HpIMPDH) inhibitors. The present study is mainly focused around our previously identified, modestly potent and relatively nonselective (for HpIMPDH over human IMPDH2) hit molecule IX (16i). In an attempt to optimize the selectivity for the bacterial enzyme, we screened a set of 48 redesigned new chemical entities (NCEs) belonging to 5-aminoisobenzofuran-1(3H)-one series for their in vitro HpIMPDH and human IMPDH2 inhibition. A total of 12 compounds (hits) demonstrated ≥70% HpIMPDH inhibition at 10 μM concentration; none of the hits were active against hIMPDH2. Compound 24 was found to be the most potent and selective molecule (HpIMPDH IC50 = 2.21 µM) in the series. The study reaffirmed the utility of 5-aminoisobenzofuran-1(3H)-one as a promising scaffold with great potential for further development of potent and selective HpIMPDH inhibitors. 相似文献
4.
To study the induction of differentiation in human melanoma cells, we treated 12 melanoma cell lines with mycophenolic acid and tiazofurin, inhibitors of IMP dehydrogenase (IMPDH). In all cell lines studied, both agents inhibited cell growth and increased melanin content. However, the degree of growth inhibition did not necessarily correspond to the increase in melanin content. A detailed analysis of the HO and SK-MEL-131 cell lines indicated that mycophenolic acid and tiazofurin caused a time- and dose-dependent increase in the expression of a series of other maturation markers, including formation of dendrite-like structures, tyrosinase activity, and reactivity with the CF21 monoclonal antibody. The growth inhibition and melanogenesis induced by the IMPDH inhibitors was abrogated by the addition of exogenous guanosine. No such effect was observed after treatment of the cells with phorbol 12-myristate 13-acetate or retinoic acid, two other inducers of differentiation in these cells. The mycophenolic acid- and tiazofurin-treated cells also showed an increased level of IMPDH mRNA and protein, perhaps because of compensation for the inhibitor-mediated decrease in IMPDH activity. In contrast, treatment with phorbol 12-myristate 13-acetate or retinoic acid resulted in decreased levels of IMPDH mRNA and protein. The lack of a consistent pattern of IMPDH expression in the cells treated with IMPDH inhibitors and phorbol 12-myristate 13-acetate or retinoic acid suggests that the altered expression of IMPDH is not a general requirement for the induction of cell differentiation in these cells. Our results also suggest that IMPDH inhibitors may provide a useful approach to circumvent the differentiation block in melanoma. 相似文献
5.
Wang G Sakthivel K Rajappan V Bruice TW Tucker K Fagan P Brooks JL Hurd T Leeds JM Cook PD 《Nucleosides, nucleotides & nucleic acids》2004,23(1-2):317-337
IMPDH inhibitors have potential antimicrobial, anticancer and immunomodulatory effects. Nucleoside inhibitors of IMPDH exert their inhibitory effects via nucleoside 5'-MPs. Conversion of nucleoside analogs to NMPs by cellular nucleoside kinases is not assured, and usually is inefficient. In order to bypass cellular phosphorylation, a series of azole nucleoside 5'-MP mimics (P1Ms) based on ribavirin, EICAR and bredinin were synthesized and screened against human and C. albicans IMP dehydrogenises. P1Ms 8, 16, 25, 28 and 29 demonstrated substantial IMPDH inhibition with Ki values in low micromolar range. 相似文献
6.
Iwanowicz EJ Watterson SH Guo J Pitts WJ Murali Dhar TG Shen Z Chen P Gu HH Fleener CA Rouleau KA Cheney DL Townsend RM Hollenbaugh DL 《Bioorganic & medicinal chemistry letters》2003,13(12):2059-2063
The first reported structure-activity relationships (SARs) about the N-[3-methoxy-4-(5-oxazolyl)phenyl moiety for a series of recently disclosed inosine monophosphate dehydrogenase (IMPDH) inhibitors are described. The syntheses and in vitro inhibitory values for IMPDH II, and T-cell proliferation (for select analogues) are given. 相似文献
7.
Dhar TG Shen Z Fleener CA Rouleau KA Barrish JC Hollenbaugh DL Iwanowicz EJ 《Bioorganic & medicinal chemistry letters》2002,12(22):3305-3308
A modified approach to the synthesis of 3-(oxazolyl-5-yl) indoles is reported. This method was applied to the synthesis of series of novel indole based inhibitors of inosine monophosphate dehydrogenase (IMPDH). The synthesis and the structure-activity relationships (SARs), derived from in vitro studies, for this new series of inhibitors is given. 相似文献
8.
Pickett SD Sherborne BS Wilkinson T Bennett J Borkakoti N Broadhurst M Hurst D Kilford I McKinnell M Jones PS 《Bioorganic & medicinal chemistry letters》2003,13(10):1691-1694
Novel, low molecular weight inhibitors of IMPDH have been discovered through the application of a validated virtual screening protocol. A series of 21 IMPDH inhibitors were used to validate the docking procedure. Application of this procedure to the selection of compounds for screening from an in-house database resulted in a 50-fold reduction in the size of the screening set (3425 to 74 compounds) and gave a hit-rate of 10% on biological evaluation. 相似文献
9.
Dhar TG Liu C Pitts WJ Guo J Watterson SH Gu H Fleener CA Rouleau K Sherbina NZ Barrish JC Hollenbaugh D Iwanowicz EJ 《Bioorganic & medicinal chemistry letters》2002,12(21):3125-3128
A series of heterocyclic replacements for the central diamide moiety of 1, a potent small molecule inhibitor of inosine monophosphate dehydrogenase (IMPDH) were explored The synthesis and the structure-activity relationships (SARs), derived from in vitro studies, for these new series of inhibitors is given. 相似文献
10.
Watterson SH Carlsen M Dhar TG Shen Z Pitts WJ Guo J Gu HH Norris D Chorba J Chen P Cheney D Witmer M Fleener CA Rouleau K Townsend R Hollenbaugh DL Iwanowicz EJ 《Bioorganic & medicinal chemistry letters》2003,13(3):543-546
A series of novel quinolone-based small molecule inhibitors of inosine monophosphate dehydrogenase (IMPDH) was explored. The synthesis and the structure-activity relationships (SARs) derived from in vitro studies are described. 相似文献
11.
Watterson SH Liu C Dhar TG Gu HH Pitts WJ Barrish JC Fleener CA Rouleau K Sherbina NZ Hollenbaugh DL Iwanowicz EJ 《Bioorganic & medicinal chemistry letters》2002,12(20):2879-2882
A series of novel amide-based small molecule inhibitors of inosine monophosphate dehydrogenase (IMPDH) was explored. The synthesis and the structure-activity relationships (SARs) derived from in vitro studies are described. 相似文献
12.
Umejiego NN Li C Riera T Hedstrom L Striepen B 《The Journal of biological chemistry》2004,279(39):40320-40327
The protozoan parasite Cryptosporidium parvum causes severe enteritis with substantial morbidity and mortality among AIDS patients and young children. No fully effective treatment is available. C. parvum relies on inosine 5'-monophosphate dehydrogenase (IMPDH) to produce guanine nucleotides and is highly susceptible to IMPDH inhibition. Furthermore, C. parvum obtained its IMPDH gene by lateral transfer from an epsilon-proteobacterium, suggesting that the parasite enzyme might have very different characteristics than the human counterpart. Here we describe the expression of recombinant C. parvum IMPDH in an Escherichia coli strain lacking the bacterial homolog. Expression of the parasite gene restores growth of this mutant on minimal medium, confirming that the protein has IMPDH activity. The recombinant protein was purified to homogeneity and used to probe the enzyme's mechanism, structure, and inhibition profile in a series of kinetic experiments. The mechanism of the C. parvum enzyme involves the random addition of substrates and ordered release of products with rate-limiting hydrolysis of a covalent enzyme intermediate. The pronounced resistance of C. parvum IMPDH to mycophenolic acid inhibition is in strong agreement with its bacterial origin. The values of Km for NAD and Ki for mycophenolic acid as well as the synergistic interaction between tiazofurin and ADP differ significantly from those of the human enzymes. These data suggest that the structure and dynamic properties of the NAD binding site of C. parvum IMPDH can be exploited to develop parasite-specific inhibitors. 相似文献
13.
M Makowska-Grzyska Y Kim R Wu R Wilton DR Gollapalli XK Wang R Zhang R Jedrzejczak JC Mack N Maltseva R Mulligan TA Binkowski P Gornicki ML Kuhn WF Anderson L Hedstrom A Joachimiak 《Biochemistry》2012,51(31):6148-6163
Inosine 5'-monophosphate dehydrogenase (IMPDH) catalyzes the first unique step of the GMP branch of the purine nucleotide biosynthetic pathway. This enzyme is found in organisms of all three kingdoms. IMPDH inhibitors have broad clinical applications in cancer treatment, as antiviral drugs and as immunosuppressants, and have also displayed antibiotic activity. We have determined three crystal structures of Bacillus anthracis IMPDH, in a phosphate ion-bound (termed "apo") form and in complex with its substrate, inosine 5'-monophosphate (IMP), and product, xanthosine 5'-monophosphate (XMP). This is the first example of a bacterial IMPDH in more than one state from the same organism. Furthermore, for the first time for a prokaryotic enzyme, the entire active site flap, containing the conserved Arg-Tyr dyad, is clearly visible in the structure of the apoenzyme. Kinetic parameters for the enzymatic reaction were also determined, and the inhibitory effect of XMP and mycophenolic acid (MPA) has been studied. In addition, the inhibitory potential of two known Cryptosporidium parvum IMPDH inhibitors was examined for the B. anthracis enzyme and compared with those of three bacterial IMPDHs from Campylobacter jejuni, Clostridium perfringens, and Vibrio cholerae. The structures contribute to the characterization of the active site and design of inhibitors that specifically target B. anthracis and other microbial IMPDH enzymes. 相似文献
14.
Watterson SH Dhar TG Ballentine SK Shen Z Barrish JC Cheney D Fleener CA Rouleau KA Townsend R Hollenbaugh DL Iwanowicz EJ 《Bioorganic & medicinal chemistry letters》2003,13(7):1273-1276
The development of a series of novel indole-based inhibitors of 5'-inosine monophosphate dehydrogenase (IMPDH) is described. Various hydrogen bond acceptors at C-3 of the indole were explored. The synthesis and the structure-activity relationships (SARs) derived from in vitro studies are outlined. 相似文献
15.
Beevers RE Buckley GM Davies N Fraser JL Galvin FC Hannah DR Haughan AF Jenkins K Mack SR Pitt WR Ratcliffe AJ Richard MD Sabin V Sharpe A Williams SC 《Bioorganic & medicinal chemistry letters》2006,16(9):2535-2538
The study of non-oxazole containing indole fragments as inhibitors of inosine monophosphate dehydrogenase (IMPDH) is described. The synthesis and in vitro inhibitory values for IMPDH II are discussed. 相似文献
16.
Liqiang Chen Riccardo Petrelli Guangyao Gao Daniel J. Wilson Garrett T. McLean Hiremagalur N. Jayaram Yuk Y. Sham Krzysztof W. Pankiewicz 《Bioorganic & medicinal chemistry》2010,18(16):5950-5964
Small molecules that act on multiple biological targets have been proposed to combat the drug resistance commonly observed for cancer chemotherapy. By combining the structural features of known inhibitors of inosine monophosphate dehydrogense (IMPDH) and histone deacetylase (HDAC), dual inhibitors of IMPDH and HDAC based on the scaffold of cinnamic hydroxamic acid (CHA) have been designed, synthesized, and evaluated in biological assays. Key features, including the linker length, linker functionality, substitution position, and interacting groups, have been explored. Their individual contribution to the inhibitory activities against human IMPDH1 and IMPDH2 as well as HDAC has been assessed. 相似文献
17.
Inosine 5'-monophosphate dehydrogenase (IMPDH) is the rate-limiting enzyme in de novo purine biosynthesis. IMPDH activity results from expression of two isoforms. Type I is constitutively expressed and predominates in normal resting cells, while Type II is selectively up-regulated in neoplastic and replicating cells. Inhibitors of IMPDH activity selectively targeting the Type II isoform have great potential as cancer chemotherapeutic agents. For this study, an expression system was developed which yields 35-50 mg of soluble, purified recombinant Type I and II protein from 1 L of bacteria. In addition, three 1,5-diazabicyclo[3.1.0]hexane-2,4-diones were synthesized and shown to act as specific inhibitors of human recombinant Type II IMPDH. The agents are competitive inhibitors with respect to the endogenous substrate IMP and K(i) values range from 5 to 44 microM but were inactive as inhibitors of the Type I isoform at concentrations ranging from 0.5 to 500 microM. IC(50) values for recombinant Type II inhibition were determined and compared to IC(50) values obtained from Molt-4 cell extracts of IMPDH. Cytotoxicity assays revealed that the compounds inhibited Molt-4 leukemia growth with ED(50) values of 3.2-7.6 microM. Computational docking studies predict that the compounds bind to IMPDH in the IMP-binding site, although interactions with residues differ from those previously determined to interact with bound IMP. While all residues predicted to interact directly with the bound compounds are conserved in the Type I and Type II isoforms, sequence divergence within a helix adjacent to the active site may contribute to the observed selectivity for the human Type II isoform. These compounds represent the first class of selective IMPDH Type II inhibitors which may serve as lead compounds for the development of isoform-selective cancer chemotherapy. 相似文献
18.
Beevers RE Buckley GM Davies N Fraser JL Galvin FC Hannah DR Haughan AF Jenkins K Mack SR Pitt WR Ratcliffe AJ Richard MD Sabin V Sharpe A Williams SC 《Bioorganic & medicinal chemistry letters》2006,16(9):2539-2542
The elaboration of previously reported indole fragments as inhibitors of inosine monophosphate dehydrogenase (IMPDH) is described. The synthesis, in vitro inhibitory values for IMPDH II, PBMC proliferation and physicochemical properties are discussed. 相似文献
19.
Birch HL Buckley GM Davies N Dyke HJ Frost EJ Gilbert PJ Hannah DR Haughan AF Madigan MJ Morgan T Pitt WR Ratcliffe AJ Ray NC Richard MD Sharpe A Taylor AJ Whitworth JM Williams SC 《Bioorganic & medicinal chemistry letters》2005,15(23):5335-5339
The synthesis and biological activity of a novel series of 7-methoxy-6-oxazol-5-yl-2,3-dihydro-1H-quinazolin-4-ones are described. Some of these compounds were found to be potent inhibitors of inosine 5'-monophosphate dehydrogenase type II (IMPDH II). 相似文献
20.
Characteristics and crystal structure of bacterial inosine-5'-monophosphate dehydrogenase 总被引:7,自引:0,他引:7
Zhang R Evans G Rotella FJ Westbrook EM Beno D Huberman E Joachimiak A Collart FR 《Biochemistry》1999,38(15):4691-4700
IMP dehydrogenase (IMPDH) is an essential enzyme that catalyzes the first step unique to GTP synthesis. To provide a basis for the evaluation of IMPDH inhibitors as antimicrobial agents, we have expressed and characterized IMPDH from the pathogenic bacterium Streptococcus pyogenes. Our results show that the biochemical and kinetic characteristics of S. pyogenes IMPDH are similar to other bacterial IMPDH enzymes. However, the lack of sensitivity to mycophenolic acid and the Km for NAD (1180 microM) exemplify some of the differences between the bacterial and mammalian IMPDH enzymes, making it an attractive target for antimicrobial agents. To evaluate the basis for these differences, we determined the crystal structure of the bacterial enzyme at 1.9 A with substrate bound in the catalytic site. The structure was determined using selenomethionine-substituted protein and multiwavelength anomalous (MAD) analysis of data obtained with synchrotron radiation from the undulator beamline (19ID) of the Structural Biology Center at Argonne's Advanced Photon Source. S. pyogenes IMPDH is a tetramer with its four subunits related by a crystallographic 4-fold axis. The protein is composed of two domains: a TIM barrel domain that embodies the catalytic framework and a cystathione beta-synthase (CBS) dimer domain of so far unknown function. Using information provided by sequence alignments and the crystal structure, we prepared several site-specific mutants to examine the role of various active site regions in catalysis. These variants implicate the active site flap as an essential catalytic element and indicate there are significant differences in the catalytic environment of bacterial and mammalian IMPDH enzymes. Comparison of the structure of bacterial IMPDH with the known partial structures from eukaryotic organisms will provide an explanation of their distinct properties and contribute to the design of specific bacterial IMPDH inhibitors. 相似文献