Xanthine oxidase is a known therapeutic target for the treatment of hyperuricemia and related diseases. Despite the availability of current drugs such as allopurinol and febuxostat, the search for new compounds to effectively inhibit this enzyme remains relevant. In our study, 75 virtual structures of 4-(5-aminosubstituted-4-cyanooxazol-2-yl)benzoic acids with structural similarity to febuxostat were designed for evaluation of their potency against xanthine oxidase.
View Article and Find Full Text PDFMicrotubules play a significant role in cell growth and functioning. Therefore inhibition of the microtubule assemblies has emerged as one of the most promising cancer treatment strategies. Predictive QSAR models were built on a series of selective inhibitors of the tubulin were performed by using Associative Neural Networks (ANN).
View Article and Find Full Text PDFAutomated docking is one of the most important tools for structure-based drug design that allows prediction of ligand binding poses and also provides an estimate of how well small molecules fit in the binding site of a protein. A new scoring function based on AutoDock and AutoDock Vina has been introduced. The new hybrid scoring function is a linear combination of the two scoring function components derived from a multiple linear regression fitting procedure.
View Article and Find Full Text PDFCurr Drug Discov Technol
August 2016
Molecular docking of small molecules in the protein binding sites is the most widely used computational technique in modern structure-based drug discovery. Although accurate prediction of binding modes of small molecules can be achieved in most cases, estimation of their binding affinities remains mediocre at best. As an attempt to improve the correlation between the inhibitory constants, pKi, and scoring, we created a new, hybrid scoring function.
View Article and Find Full Text PDFMonoester derivatives of thiacalix[4]arene tetrakis(methylphosphonic) acid were found to be capable of inhibiting protein tyrosine phosphatase 1B. In addition, these compounds can strongly bind to human serum albumin.
View Article and Find Full Text PDFα,α-Difluoro-β-ketophosphonated derivatives of tetraazamacrocycles were synthesized and found to be potential inhibitors of protein tyrosine phosphatases. N-Substituted conjugates of cyclam and cyclen with bioisosteric phosphonate groups displayed good activities toward T-cell protein tyrosine phosphatase with IC50 values in the micromolar to nanomolar range and showed selectivity over PTP1B, CD45, SHP2, and PTPβ. Kinetic studies indicated that the inhibitors can occupy the region of the active site of TC-PTP.
View Article and Find Full Text PDFIn this study, we identified water-soluble C60 and C70 fullerene derivatives as a novel class of protein tyrosine phosphatase inhibitors. The evaluated compounds were found to inhibit CD45, PTP1B, TC-PTP, SHP2, and PTPβ with IC50 values in the low micromolar to high nanomolar range. These results demonstrate a new strategy for designing effective nanoscale protein tyrosine phosphatase inhibitors.
View Article and Find Full Text PDFCurr Comput Aided Drug Des
October 2015
Quantitative structure-activity relationship studies on a series of selective inhibitors of thrombin and factor Xa were performed by using Associative Neural Network. To overcome the problem of overfitting due to descriptor selection, 5-fold cross-validation with variable selection in each step of the analysis was performed. The predictive ability of the models was tested through leave-one-out cross-validation, giving a Q2=0.
View Article and Find Full Text PDFСalix[4]arenes bearing methylenebisphosphonic or hydroxymethylenebisphosphonic acid fragments at the wide rim of the macrocycle were studied as inhibitors of PTP1B. Some of the inhibitors showed IC50 values in the micromolar range and good selectivity in comparison with other protein tyrosine phosphatases such as TC-PTP, PTPβ, LAR, and CD45. Kinetic studies indicated that the calix[4]arene derivatives influence PTP1B activity as slow-binding inhibitors.
View Article and Find Full Text PDFHundred and two binding sites from 91 Protein Data Bank files for protein tyrosine phosphatase 1B with different ligands have been compared. It was found that they can be divided into five clusters. Additional clusters were formed by the unliganded and oxidized enzyme.
View Article and Find Full Text PDFA series of diverse organic compounds, phosphodiesterase type 4 (PDE-4) inhibitors, have been modeled using a QSAR-based approach. 48 QSAR models were compared by following the same procedure with different combinations of descriptors and machine learning methods. QSAR methodologies used random forests and associative neural networks.
View Article and Find Full Text PDFThe Online Chemical Modeling Environment is a web-based platform that aims to automate and simplify the typical steps required for QSAR modeling. The platform consists of two major subsystems: the database of experimental measurements and the modeling framework. A user-contributed database contains a set of tools for easy input, search and modification of thousands of records.
View Article and Find Full Text PDFInhibition of Yersinia protein tyrosine phosphatase by calix[4]arene mono-, bis-, and tetrakis(methylenebisphosphonic) acids as well as calix[4]arene and thiacalix[4]arene tetrakis(methylphosphonic) acids have been investigated. The kinetic studies revealed that some compounds in this class are potent competitive inhibitors of Yersinia PTP with inhibition constants in the low micromolar range. The binding modes of macrocyclic phosphonate derivatives in the enzyme active center have been explained using computational docking approach.
View Article and Find Full Text PDFThe inhibition effects of enantiomerically pure alpha-(N-benzylamino)benzylphosphonic acids and their derivatives on human prostatic acid phosphatase have been investigated. As expected, (R)-alpha-(N-benzylamino)benzylphosphonic acid demonstrated higher affinity for the enzyme than (S)-enantiomer. At the same time, (1R,2S)-phenyl[(1-phenylethyl)amino]methylphosphonic acid was found to be a significantly weaker inhibitor than its (1S,2R)-analogue.
View Article and Find Full Text PDFInternet technology offers an excellent opportunity for the development of tools by the cooperative effort of various groups and institutions. We have developed a multi-platform software system, Virtual Computational Chemistry Laboratory, http://www.vcclab.
View Article and Find Full Text PDFJ Chem Inf Comput Sci
November 2002
This article provides a systematic study of several important parameters of the Associative Neural Network (ASNN), such as the number of networks in the ensemble, distance measures, neighbor functions, selection of smoothing parameters, and strategies for the user-training feature of the algorithm. The performance of the different methods is assessed with several training/test sets used to predict lipophilicity of chemical compounds. The Spearman rank-order correlation coefficient and Parzen-window regression methods provide the best performance of the algorithm.
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