Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 100
Filtrar
Más filtros

Tipo del documento
Intervalo de año de publicación
1.
J Chem Inf Model ; 64(2): 348-358, 2024 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-38170877

RESUMEN

The ability to determine and predict metabolically labile atom positions in a molecule (also called "sites of metabolism" or "SoMs") is of high interest to the design and optimization of bioactive compounds, such as drugs, agrochemicals, and cosmetics. In recent years, several in silico models for SoM prediction have become available, many of which include a machine-learning component. The bottleneck in advancing these approaches is the coverage of distinct atom environments and rare and complex biotransformation events with high-quality experimental data. Pharmaceutical companies typically have measured metabolism data available for several hundred to several thousand compounds. However, even for metabolism experts, interpreting these data and assigning SoMs are challenging and time-consuming. Therefore, a significant proportion of the potential of the existing metabolism data, particularly in machine learning, remains dormant. Here, we report on the development and validation of an active learning approach that identifies the most informative atoms across molecular data sets for SoM annotation. The active learning approach, built on a highly efficient reimplementation of SoM predictor FAME 3, enables experts to prioritize their SoM experimental measurements and annotation efforts on the most rewarding atom environments. We show that this active learning approach yields competitive SoM predictors while requiring the annotation of only 20% of the atom positions required by FAME 3. The source code of the approach presented in this work is publicly available.


Asunto(s)
Aprendizaje Automático , Programas Informáticos
2.
Int J Mol Sci ; 24(13)2023 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-37446241

RESUMEN

The prediction of drug metabolism is attracting great interest for the possibility of discarding molecules with unfavorable ADME/Tox profile at the early stage of the drug discovery process. In this context, artificial intelligence methods can generate highly performing predictive models if they are trained by accurate metabolic data. MetaQSAR-based datasets were collected to predict the sites of metabolism for most metabolic reactions. The models were based on a set of structural, physicochemical, and stereo-electronic descriptors and were generated by the random forest algorithm. For each considered biotransformation, two types of models were developed: the first type involved all non-reactive atoms and included atom types among the descriptors, while the second type involved only non-reactive centers having the same atom type(s) of the reactive atoms. All the models of the first type revealed very high performances; the models of the second type show on average worst performances while being almost always able to recognize the reactive centers; only conjugations with glucuronic acid are unsatisfactorily predicted by the models of the second type. Feature evaluation confirms the major role of lipophilicity, self-polarizability, and H-bonding for almost all considered reactions. The obtained results emphasize the possibility of recognizing the sites of metabolism by classification models trained on MetaQSAR database. The two types of models can be synergistically combined since the first models identify which atoms can undergo a given metabolic reactions, while the second models detect the truly reactive centers. The generated models are available as scripts for the VEGA program.


Asunto(s)
Inteligencia Artificial , Bases de Datos Factuales , Fenómenos Químicos , Biotransformación
3.
Int J Mol Sci ; 25(1)2023 Dec 29.
Artículo en Inglés | MEDLINE | ID: mdl-38203621

RESUMEN

Phenotypic screenings are usually combined with deconvolution techniques to characterize the mechanism of action for the retrieved hits. These studies can be supported by various computational analyses, although docking simulations are rarely employed. The present study aims to assess if multiple docking calculations can prove successful in target prediction. In detail, the docking simulations submitted to the MEDIATE initiative are utilized to predict the viral targets involved in the hits retrieved by a recently published cytopathic screening. Multiple docking results are combined by the EFO approach to develop target-specific consensus models. The combination of multiple docking simulations enhances the performances of the developed consensus models (average increases in EF1% value of 40% and 25% when combining three and two docking runs, respectively). These models are able to propose reliable targets for about half of the retrieved hits (31 out of 59). Thus, the study emphasizes that docking simulations might be effective in target identification and provide a convincing validation for the collaborative strategies that inspire the MEDIATE initiative. Disappointingly, cross-target and cross-program correlations suggest that common scoring functions are not specific enough for the simulated target.


Asunto(s)
COVID-19 , Humanos , COVID-19/diagnóstico , SARS-CoV-2 , Consenso
4.
Molecules ; 28(7)2023 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-37049856

RESUMEN

Obesity and type 2 diabetes (T2DM) are major public health concerns associated with serious morbidity and increased mortality. Both obesity and T2DM are strongly associated with adiposopathy, a term that describes the pathophysiological changes of the adipose tissue. In this review, we have highlighted adipose tissue dysfunction as a major factor in the etiology of these conditions since it promotes chronic inflammation, dysregulated glucose homeostasis, and impaired adipogenesis, leading to the accumulation of ectopic fat and insulin resistance. This dysfunctional state can be effectively ameliorated by the loss of at least 15% of body weight, that is correlated with better glycemic control, decreased likelihood of cardiometabolic disease, and an improvement in overall quality of life. Weight loss can be achieved through lifestyle modifications (healthy diet, regular physical activity) and pharmacotherapy. In this review, we summarized different effective management strategies to address weight loss, such as bariatric surgery and several classes of drugs, namely metformin, GLP-1 receptor agonists, amylin analogs, and SGLT2 inhibitors. These drugs act by targeting various mechanisms involved in the pathophysiology of obesity and T2DM, and they have been shown to induce significant weight loss and improve glycemic control in obese individuals with T2DM.


Asunto(s)
Cirugía Bariátrica , Diabetes Mellitus Tipo 2 , Humanos , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Calidad de Vida , Obesidad/terapia , Obesidad/tratamiento farmacológico , Pérdida de Peso
5.
Proteins ; 90(2): 372-384, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34455628

RESUMEN

Antibiotic resistance is a major threat to global public health. ß-lactamases, which catalyze breakdown of ß-lactam antibiotics, are a principal cause. Metallo ß-lactamases (MBLs) represent a particular challenge because they hydrolyze almost all ß-lactams and to date no MBL inhibitor has been approved for clinical use. Molecular simulations can aid drug discovery, for example, predicting inhibitor complexes, but empirical molecular mechanics (MM) methods often perform poorly for metalloproteins. Here we present a multiscale approach to model thiol inhibitor binding to IMP-1, a clinically important MBL containing two catalytic zinc ions, and predict the binding mode of a 2-mercaptomethyl thiazolidine (MMTZ) inhibitor. Inhibitors were first docked into the IMP-1 active site, testing different docking programs and scoring functions on multiple crystal structures. Complexes were then subjected to molecular dynamics (MD) simulations and subsequently refined through QM/MM optimization with a density functional theory (DFT) method, B3LYP/6-31G(d), increasing the accuracy of the method with successive steps. This workflow was tested on two IMP-1:MMTZ complexes, for which it reproduced crystallographically observed binding, and applied to predict the binding mode of a third MMTZ inhibitor for which a complex structure was crystallographically intractable. We also tested a 12-6-4 nonbonded interaction model in MD simulations and optimization with a SCC-DFTB QM/MM approach. The results show the limitations of empirical models for treating these systems and indicate the need for higher level calculations, for example, DFT/MM, for reliable structural predictions. This study demonstrates a reliable computational pipeline that can be applied to inhibitor design for MBLs and other zinc-metalloenzyme systems.


Asunto(s)
Antibacterianos/química , Inhibidores de beta-Lactamasas/química , beta-Lactamasas/química , beta-Lactamas/química , Dominio Catalítico , Modelos Moleculares , Zinc
6.
Bioinformatics ; 37(8): 1174-1175, 2021 05 23.
Artículo en Inglés | MEDLINE | ID: mdl-33289523

RESUMEN

The purpose of the article is to offer an overview of the latest release of the VEGA suite of programs. This software has been constantly developed and freely released during the last 20 years and has now reached a significant diffusion and technology level as confirmed by the about 22 500 registered users. While being primarily developed for drug design studies, the VEGA package includes cheminformatics and modeling features, which can be fruitfully utilized in various contexts of the computational chemistry. To offer a glimpse of the remarkable potentials of the software, some examples of the implemented features in the cheminformatics field and for structure-based studies are discussed. Finally, the flexible architecture of the VEGA program which can be expanded and customized by plug-in technology or scripting languages will be described focusing attention on the HyperDrive library including highly optimized functions. AVAILABILITY AND IMPLEMENTATION: The VEGA suite of programs and the source code of the VEGA command-line version are available free of charge for non-profit organizations at http://www.vegazz.net.


Asunto(s)
Quimioinformática , Bibliotecas , Diseño de Fármacos , Programas Informáticos
7.
Int J Mol Sci ; 23(14)2022 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-35886905

RESUMEN

(1) Background: Virtual screening campaigns require target structures in which the pockets are properly arranged for binding. Without these, MD simulations can be used to relax the available target structures, optimizing the fine architecture of their binding sites. Among the generated frames, the best structures can be selected based on available experimental data. Without experimental templates, the MD trajectories can be filtered by energy-based criteria or sampled by systematic analyses. (2) Methods: A blind and methodical analysis was performed on the already reported MD run of the hTRPM8 tetrameric structures; a total of 50 frames underwent docking simulations by using a set of 1000 ligands including 20 known hTRPM8 modulators. Docking runs were performed by LiGen program and involved the frames as they are and after optimization by SCRWL4.0. For each frame, all four monomers were considered. Predictive models were developed by the EFO algorithm based on the sole primary LiGen scores. (3) Results: On average, the MD simulation progressively enhances the performance of the extracted frames, and the optimized structures perform better than the non-optimized frames (EF1% mean: 21.38 vs. 23.29). There is an overall correlation between performances and volumes of the explored pockets and the combination of the best performing frames allows to develop highly performing consensus models (EF1% = 49.83). (4) Conclusions: The systematic sampling of the entire MD run provides performances roughly comparable with those previously reached by using rationally selected frames. The proposed strategy appears to be helpful when the lack of experimental data does not allow an easy selection of the optimal structures for docking simulations. Overall, the reported docking results confirm the relevance of simulating all the monomers of an oligomer structure and emphasize the efficacy of the SCRWL4.0 method to optimize the protein structures for docking calculations.


Asunto(s)
Simulación de Dinámica Molecular , Proteínas , Sitios de Unión , Ligandos , Simulación del Acoplamiento Molecular , Unión Proteica , Proteínas/química
8.
Molecules ; 26(19)2021 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-34641400

RESUMEN

(1) Background: Machine learning algorithms are finding fruitful applications in predicting the ADME profile of new molecules, with a particular focus on metabolism predictions. However, the development of comprehensive metabolism predictors is hampered by the lack of highly accurate metabolic resources. Hence, we recently proposed a manually curated metabolic database (MetaQSAR), the level of accuracy of which is well suited to the development of predictive models. (2) Methods: MetaQSAR was used to extract datasets to predict the metabolic reactions subdivided into major classes, classes and subclasses. The collected datasets comprised a total of 3788 first-generation metabolic reactions. Predictive models were developed by using standard random forest algorithms and sets of physicochemical, stereo-electronic and constitutional descriptors. (3) Results: The developed models showed satisfactory performance, especially for hydrolyses and conjugations, while redox reactions were predicted with greater difficulty, which was reasonable as they depend on many complex features that are not properly encoded by the included descriptors. (4) Conclusions: The generated models allowed a precise comparison of the propensity of each metabolic reaction to be predicted and the factors affecting their predictability were discussed in detail. Overall, the study led to the development of a freely downloadable global predictor, MetaClass, which correctly predicts 80% of the reported reactions, as assessed by an explorative validation analysis on an external dataset, with an overall MCC = 0.44.

9.
Molecules ; 26(7)2021 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-33917533

RESUMEN

(1) Background: Data accuracy plays a key role in determining the model performances and the field of metabolism prediction suffers from the lack of truly reliable data. To enhance the accuracy of metabolic data, we recently proposed a manually curated database collected by a meta-analysis of the specialized literature (MetaQSAR). Here we aim to further increase data accuracy by focusing on publications reporting exhaustive metabolic trees. This selection should indeed reduce the number of false negative data. (2) Methods: A new metabolic database (MetaTREE) was thus collected and utilized to extract a dataset for metabolic data concerning glutathione conjugation (MT-dataset). After proper pre-processing, this dataset, along with the corresponding dataset extracted from MetaQSAR (MQ-dataset), was utilized to develop binary classification models using a random forest algorithm. (3) Results: The comparison of the models generated by the two collected datasets reveals the better performances reached by the MT-dataset (MCC raised from 0.63 to 0.67, sensitivity from 0.56 to 0.58). The analysis of the applicability domain also confirms that the model based on the MT-dataset shows a more robust predictive power with a larger applicability domain. (4) Conclusions: These results confirm that focusing on metabolic trees represents a convenient approach to increase data accuracy by reducing the false negative cases. The encouraging performances shown by the models developed by the MT-dataset invites to use of MetaTREE for predictive studies in the field of xenobiotic metabolism.


Asunto(s)
Bases de Datos Factuales , Glutatión/metabolismo , Redes y Vías Metabólicas , Análisis de Datos , Inactivación Metabólica , Análisis de Componente Principal , Programas Informáticos
10.
Molecules ; 26(4)2021 Feb 04.
Artículo en Inglés | MEDLINE | ID: mdl-33557115

RESUMEN

The 3CL-Protease appears to be a very promising medicinal target to develop anti-SARS-CoV-2 agents. The availability of resolved structures allows structure-based computational approaches to be carried out even though the lack of known inhibitors prevents a proper validation of the performed simulations. The innovative idea of the study is to exploit known inhibitors of SARS-CoV 3CL-Pro as a training set to perform and validate multiple virtual screening campaigns. Docking simulations using four different programs (Fred, Glide, LiGen, and PLANTS) were performed investigating the role of both multiple binding modes (by binding space) and multiple isomers/states (by developing the corresponding isomeric space). The computed docking scores were used to develop consensus models, which allow an in-depth comparison of the resulting performances. On average, the reached performances revealed the different sensitivity to isomeric differences and multiple binding modes between the four docking engines. In detail, Glide and LiGen are the tools that best benefit from isomeric and binding space, respectively, while Fred is the most insensitive program. The obtained results emphasize the fruitful role of combining various docking tools to optimize the predictive performances. Taken together, the performed simulations allowed the rational development of highly performing virtual screening workflows, which could be further optimized by considering different 3CL-Pro structures and, more importantly, by including true SARS-CoV-2 3CL-Pro inhibitors (as learning set) when available.


Asunto(s)
COVID-19/virología , Proteasas 3C de Coronavirus/metabolismo , SARS-CoV-2/enzimología , Antivirales/química , Antivirales/farmacología , Sitios de Unión , Proteasas 3C de Coronavirus/antagonistas & inhibidores , Proteasas 3C de Coronavirus/química , Diseño de Fármacos , Evaluación Preclínica de Medicamentos/métodos , Reposicionamiento de Medicamentos/métodos , Humanos , Modelos Moleculares , Simulación del Acoplamiento Molecular/métodos , Péptido Hidrolasas/metabolismo , Inhibidores de Proteasas/química , Inhibidores de Proteasas/farmacología , Conformación Proteica , Tratamiento Farmacológico de COVID-19
11.
Int J Mol Sci ; 21(17)2020 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-32825082

RESUMEN

Structure-based virtual screening is a truly productive repurposing approach provided that reliable target structures are available. Recent progresses in the structural resolution of the G-Protein Coupled Receptors (GPCRs) render these targets amenable for structure-based repurposing studies. Hence, the present study describes structure-based virtual screening campaigns with a view to repurposing known drugs as potential allosteric (and/or orthosteric) ligands for the hM2 muscarinic subtype which was indeed resolved in complex with an allosteric modulator thus allowing a precise identification of this binding cavity. First, a docking protocol was developed and optimized based on binding space concept and enrichment factor optimization algorithm (EFO) consensus approach by using a purposely collected database including known allosteric modulators. The so-developed consensus models were then utilized to virtually screen the DrugBank database. Based on the computational results, six promising molecules were selected and experimentally tested and four of them revealed interesting affinity data; in particular, dequalinium showed a very impressive allosteric modulation for hM2. Based on these results, a second campaign was focused on bis-cationic derivatives and allowed the identification of other two relevant hM2 ligands. Overall, the study enhances the understanding of the factors governing the hM2 allosteric modulation emphasizing the key role of ligand flexibility as well as of arrangement and delocalization of the positively charged moieties.


Asunto(s)
Sitio Alostérico , Antiinfecciosos Locales/farmacología , Colinérgicos/farmacología , Decualinio/farmacología , Reposicionamiento de Medicamentos , Receptores Muscarínicos/química , Regulación Alostérica , Animales , Antiinfecciosos Locales/química , Células CHO , Colinérgicos/química , Cricetinae , Cricetulus , Decualinio/química , Humanos , Ligandos , Simulación del Acoplamiento Molecular , Unión Proteica , Receptores Muscarínicos/metabolismo
12.
Int J Mol Sci ; 21(7)2020 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-32218173

RESUMEN

BACKGROUND: There is an increasing interest in TRPM8 ligands of medicinal interest, the rational design of which can be nowadays supported by structure-based in silico studies based on the recently resolved TRPM8 structures. Methods: The study involves the generation of a reliable hTRPM8 homology model, the reliability of which was assessed by a 1.0 µs MD simulation which was also used to generate multiple receptor conformations for the following structure-based virtual screening (VS) campaigns; docking simulations utilized different programs and involved all monomers of the selected frames; the so computed docking scores were combined by consensus approaches based on the EFO algorithm. Results: The obtained models revealed very satisfactory performances; LiGen™ provided the best results among the tested docking programs; the combination of docking results from the four monomers elicited a markedly beneficial effect on the computed consensus models. Conclusions: The generated hTRPM8 model appears to be amenable for successful structure-based VS studies; cross-talk modulating effects between interacting monomers on the binding sites can be accounted for by combining docking simulations as performed on all the monomers; this strategy can have general applicability for docking simulations involving quaternary protein structures with multiple identical binding pockets.


Asunto(s)
Canales Catiónicos TRPM/metabolismo , Humanos , Modelos Moleculares , Simulación de Dinámica Molecular , Unión Proteica , Estructura Cuaternaria de Proteína , Estructura Terciaria de Proteína , Canales Catiónicos TRPM/genética
13.
Int J Mol Sci ; 21(14)2020 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-32708196

RESUMEN

(1) Background: Virtual screening studies on the therapeutically relevant proteins of the severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) require a detailed characterization of their druggable binding sites, and, more generally, a convenient pocket mapping represents a key step for structure-based in silico studies; (2) Methods: Along with a careful literature search on SARS-CoV-2 protein targets, the study presents a novel strategy for pocket mapping based on the combination of pocket (as performed by the well-known FPocket tool) and docking searches (as performed by PLANTS or AutoDock/Vina engines); such an approach is implemented by the Pockets 2.0 plug-in for the VEGA ZZ suite of programs; (3) Results: The literature analysis allowed the identification of 16 promising binding cavities within the SARS-CoV-2 proteins and the here proposed approach was able to recognize them showing performances clearly better than those reached by the sole pocket detection; and (4) Conclusions: Even though the presented strategy should require more extended validations, this proved successful in precisely characterizing a set of SARS-CoV-2 druggable binding pockets including both orthosteric and allosteric sites, which are clearly amenable for virtual screening campaigns and drug repurposing studies. All results generated by the study and the Pockets 2.0 plug-in are available for download.


Asunto(s)
Antivirales/química , Betacoronavirus/efectos de los fármacos , Infecciones por Coronavirus/tratamiento farmacológico , Neumonía Viral/tratamiento farmacológico , Proteínas Virales/química , Sitios de Unión/efectos de los fármacos , COVID-19 , Reposicionamiento de Medicamentos , Humanos , Simulación del Acoplamiento Molecular , Pandemias , Unión Proteica/efectos de los fármacos , Conformación Proteica , SARS-CoV-2
14.
Molecules ; 25(8)2020 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-32340373

RESUMEN

Diabetes Mellitus (DM) is a multi-factorial chronic health condition that affects a large part of population and according to the World Health Organization (WHO) the number of adults living with diabetes is expected to increase. Since type 2 diabetes mellitus (T2DM) is suffered by the majority of diabetic patients (around 90-95%) and often the mono-target therapy fails in managing blood glucose levels and the other comorbidities, this review focuses on the potential drugs acting on multi-targets involved in the treatment of this type of diabetes. In particular, the review considers the main systems directly involved in T2DM or involved in diabetes comorbidities. Agonists acting on incretin, glucagon systems, as well as on peroxisome proliferation activated receptors are considered. Inhibitors which target either aldose reductase and tyrosine phosphatase 1B or sodium glucose transporters 1 and 2 are taken into account. Moreover, with a view at the multi-target approaches for T2DM some phytocomplexes are also discussed.


Asunto(s)
Biomarcadores , Diabetes Mellitus Tipo 2/etiología , Diabetes Mellitus Tipo 2/metabolismo , Descubrimiento de Drogas , Hipoglucemiantes/farmacología , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Susceptibilidad a Enfermedades , Diseño de Fármacos , Evaluación Preclínica de Medicamentos , Glucosa/metabolismo , Humanos , Hipoglucemiantes/uso terapéutico , Incretinas/química , Incretinas/farmacología , Incretinas/uso terapéutico , Ligandos , Terapia Molecular Dirigida , Relación Estructura-Actividad
15.
Molecules ; 25(15)2020 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-32752073

RESUMEN

Signal transducer and activator of transcription 3 (STAT3) is a validated anticancer target due to the relationship between its constitutive activation and malignant tumors. Through a virtual screening approach on the STAT3-SH2 domain, 5,6-dimethyl-1H,3H-2,1,3-benzothiadiazole-2,2-dioxide (1) was identified as a potential STAT3 inhibitor. Some benzothiadiazole derivatives were synthesized by employing a versatile methodology, and they were tested by an AlphaScreen-based assay. Among them, benzosulfamide 1 showed a significant activity with an IC50 = 15.8 ± 0.6 µM as a direct STAT3 inhibitor. Notably, we discovered that compound 1 was also able to interact with cysteine residues located around the SH2 domain. By applying mass spectrometry, liquid chromatography, NMR, and UV spectroscopy, an in-depth investigation was carried out, shedding light on its intriguing and unexpected mechanism of interaction.


Asunto(s)
Factor de Transcripción STAT3/metabolismo , Tiadiazoles/química , Sitios de Unión , Diseño de Fármacos , Humanos , Simulación del Acoplamiento Molecular , Mutagénesis Sitio-Dirigida , Dominios y Motivos de Interacción de Proteínas/efectos de los fármacos , Factor de Transcripción STAT3/antagonistas & inhibidores , Factor de Transcripción STAT3/genética , Relación Estructura-Actividad , Tiadiazoles/metabolismo , Tiadiazoles/farmacología , Dominios Homologos src
16.
J Chem Inf Model ; 59(8): 3400-3412, 2019 08 26.
Artículo en Inglés | MEDLINE | ID: mdl-31361490

RESUMEN

In this work we present the third generation of FAst MEtabolizer (FAME 3), a collection of extra trees classifiers for the prediction of sites of metabolism (SoMs) in small molecules such as drugs, druglike compounds, natural products, agrochemicals, and cosmetics. FAME 3 was derived from the MetaQSAR database ( Pedretti et al. J. Med. Chem. 2018 , 61 , 1019 ), a recently published data resource on xenobiotic metabolism that contains more than 2100 substrates annotated with more than 6300 experimentally confirmed SoMs related to redox reactions, hydrolysis and other nonredox reactions, and conjugation reactions. In tests with holdout data, FAME 3 models reached competitive performance, with Matthews correlation coefficients (MCCs) ranging from 0.50 for a global model covering phase 1 and phase 2 metabolism, to 0.75 for a focused model for phase 2 metabolism. A model focused on cytochrome P450 metabolism yielded an MCC of 0.57. Results from case studies with several synthetic compounds, natural products, and natural product derivatives demonstrate the agreement between model predictions and literature data even for molecules with structural patterns clearly distinct from those present in the training data. The applicability domains of the individual models were estimated by a new, atom-based distance measure (FAMEscore) that is based on a nearest-neighbor search in the space of atom environments. FAME 3 is available via a public web service at https://nerdd.zbh.uni-hamburg.de/ and as a self-contained Java software package, free for academic and noncommercial research.


Asunto(s)
Productos Biológicos/metabolismo , Biología Computacional/métodos , Enzimas/metabolismo , Sitios de Unión , Bases de Datos Farmacéuticas , Enzimas/química
17.
Int J Mol Sci ; 20(9)2019 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-31027337

RESUMEN

The study proposes a novel consensus strategy based on linear combinations of different docking scores to be used in the evaluation of virtual screening campaigns. The consensus models are generated by applying the recently proposed Enrichment Factor Optimization (EFO) method, which develops the linear equations by exhaustively combining the available docking scores and by optimizing the resulting enrichment factors. The performances of such a consensus strategy were evaluated by simulating the entire Directory of Useful Decoys (DUD datasets). In detail, the poses were initially generated by the PLANTS docking program and then rescored by ReScore+ with and without the minimization of the complexes. The so calculated scores were then used to generate the mentioned consensus models including two or three different scoring functions. The reliability of the generated models was assessed by a per target validation as performed by default by the EFO approach. The encouraging performances of the here proposed consensus strategy are emphasized by the average increase of the 17% in the Top 1% enrichment factor (EF) values when comparing the single best score with the linear combination of three scores. Specifically, kinases offer a truly convincing demonstration of the efficacy of the here proposed consensus strategy since their Top 1% EF average ranges from 6.4 when using the single best performing primary score to 23.5 when linearly combining scoring functions. The beneficial effects of this consensus approach are clearly noticeable even when considering the entire DUD datasets as evidenced by the area under the curve (AUC) averages revealing a 14% increase when combining three scores. The reached AUC values compare very well with those reported in literature by an extended set of recent benchmarking studies and the three-variable models afford the highest AUC average.


Asunto(s)
Bases de Datos Factuales , Área Bajo la Curva , Consenso , Simulación del Acoplamiento Molecular , Unión Proteica , Proteínas
18.
J Chem Inf Model ; 58(6): 1154-1160, 2018 06 25.
Artículo en Inglés | MEDLINE | ID: mdl-29746777

RESUMEN

The manuscript describes WarpEngine, a novel platform implemented within the VEGA ZZ suite of software for performing distributed simulations both in local and wide area networks. Despite being tailored for structure-based virtual screening campaigns, WarpEngine possesses the required flexibility to carry out distributed calculations utilizing various pieces of software, which can be easily encapsulated within this platform without changing their source codes. WarpEngine takes advantages of all cheminformatics features implemented in the VEGA ZZ program as well as of its largely customizable scripting architecture thus allowing an efficient distribution of various time-demanding simulations. To offer an example of the WarpEngine potentials, the manuscript includes a set of virtual screening campaigns based on the ACE data set of the DUD-E collections using PLANTS as the docking application. Benchmarking analyses revealed a satisfactory linearity of the WarpEngine performances, the speed-up values being roughly equal to the number of utilized cores. Again, the computed scalability values emphasized that a vast majority (i.e., >90%) of the performed simulations benefit from the distributed platform presented here. WarpEngine can be freely downloaded along with the VEGA ZZ program at www.vegazz.net .


Asunto(s)
Redes de Comunicación de Computadores , Programas Informáticos , Biología Computacional/instrumentación , Redes de Comunicación de Computadores/instrumentación , Gráficos por Computador/instrumentación , Descubrimiento de Drogas/instrumentación , Diseño de Equipo
19.
Molecules ; 23(11)2018 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-30428514

RESUMEN

The study is aimed at developing linear classifiers to predict the capacity of a given substrate to yield reactive metabolites. While most of the hitherto reported predictive models are based on the occurrence of known structural alerts (e.g., the presence of toxophoric groups), the present study is focused on the generation of predictive models involving linear combinations of physicochemical and stereo-electronic descriptors. The development of these models is carried out by using a novel classification approach based on enrichment factor optimization (EFO) as implemented in the VEGA suite of programs. The study took advantage of metabolic data as collected by manually curated analysis of the primary literature and published in the years 2004⁻2009. The learning set included 977 substrates among which 138 compounds yielded reactive first-generation metabolites, plus 212 substrates generating reactive metabolites in all generations (i.e., metabolic steps). The results emphasized the possibility of developing satisfactory predictive models especially when focusing on the first-generation reactive metabolites. The extensive comparison of the classifier approach presented here using a set of well-known algorithms implemented in Weka 3.8 revealed that the proposed EFO method compares with the best available approaches and offers two relevant benefits since it involves a limited number of descriptors and provides a score-based probability thus allowing a critical evaluation of the obtained results. The last analyses on non-cheminformatics UCI datasets emphasize the general applicability of the EFO approach, which conveniently performs using both balanced and unbalanced datasets.


Asunto(s)
Biotransformación , Aprendizaje Automático , Modelos Estadísticos , Fenómenos Farmacológicos y Toxicológicos , Algoritmos
20.
Bioinformatics ; 32(17): 2672-80, 2016 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-27162187

RESUMEN

MOTIVATION: Vaccines represent the most effective and cost-efficient weapons against a wide range of diseases. Nowadays new generation vaccines based on subunit antigens reduce adverse effects in high risk individuals. However, vaccine antigens are often poor immunogens when administered alone. Adjuvants represent a good strategy to overcome such hurdles, indeed they are able to: enhance the immune response; allow antigens sparing; accelerate the specific immune response; and increase vaccine efficacy in vulnerable groups such as newborns, elderly or immuno-compromised people. However, due to safety concerns and adverse reactions, there are only a few adjuvants approved for use in humans. Moreover, in practice current adjuvants sometimes fail to confer adequate stimulation. Hence, there is an imperative need to develop novel adjuvants that overcome the limitations of the currently available licensed adjuvants. RESULTS: We developed a computational framework that provides a complete pipeline capable of predicting the best citrus-derived adjuvants for enhancing the immune system response using, as a target disease model, influenza A infection. In silico simulations suggested a good immune efficacy of specific citrus-derived adjuvant (Beta Sitosterol) that was then confirmed in vivoAvailability: The model is available visiting the following URL: http://vaima.dmi.unict.it/AdjSim CONTACT: francesco.pappalardo@unict.it; fp@francescopappalardo.net.


Asunto(s)
Adyuvantes Inmunológicos , Citrus , Sistema Inmunológico , Vacunas contra la Influenza , Anciano , Antígenos , Predicción , Humanos , Huésped Inmunocomprometido , Recién Nacido , Modelación Específica para el Paciente
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA