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1.
Acta Crystallogr F Struct Biol Commun ; 77(Pt 1): 22-28, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33439152

RESUMO

Hematopoietic progenitor kinase 1 (HPK1) is an intracellular kinase that plays an important role in modulating tumor immune response and thus is an attractive target for drug discovery. Crystallization of the wild-type HPK1 kinase domain has been hampered by poor expression in recombinant systems and poor solubility. In this study, yeast surface display was applied to a library of HPK1 kinase-domain variants in order to select variants with an improved expression level and solubility. The HPK1 variant with the most improved properties contained two mutations, crystallized readily in complex with several small-molecule inhibitors and provided valuable insight to guide structure-based drug design. This work exemplifies the benefit of yeast surface display towards engineering crystallizable proteins and thus enabling structure-based drug discovery.

2.
J Med Chem ; 63(23): 15050-15071, 2020 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-33261314

RESUMO

Scaffold hopping and structure-based drug design were employed to identify substituted 4-aminoquinolines and 4-aminonaphthyridines as potent, small molecule inhibitors of tumor necrosis factor alpha (TNFα). Structure-activity relationships in both the quinoline and naphthyridine series leading to the identification of compound 42 with excellent potency and pharmacokinetic profile are discussed. X-ray co-crystal structure analysis and ultracentrifugation experiments clearly demonstrate that these inhibitors distort the TNFα trimer upon binding, leading to aberrant signaling when the trimer binds to TNF receptor 1 (TNFR1). Pharmacokinetic-pharmacodynamic activity of compound 42 in a TNF-induced IL-6 mouse model and in vivo activity in a collagen antibody-induced arthritis model, where it showed biologic-like in vivo efficacy, will be discussed.

3.
Bioorg Med Chem Lett ; 30(22): 127531, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32890685

RESUMO

Previous studies have identified a series of imidazo[1,2-a]pyridine (IZP) derivatives as potent allosteric inhibitors of HIV-1 integrase (ALLINIs) and virus infection in cell culture. However, IZPs were also found to be relatively potent activators of the pregnane-X receptor (PXR), raising the specter of induction of CYP-mediated drug disposition pathways. In an attempt to modify PXR activity without affecting anti-HIV-1 activity, rational structure-based design and modeling approaches were used. An X-ray cocrystal structure of (S,S)-1 in the PXR ligand binding domain (LBD) allowed an examination of the potential of rational structural modifications designed to abrogate PXR. The introduction of bulky basic amines at the C-8 position provided macrocyclic IZP derivatives that displayed potent HIV-1 inhibitory activity in cell culture with no detectable PXR transactivation at the highest concentration tested.

4.
J Immunol ; 202(1): 151-159, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30530595

RESUMO

The FcγRs are immune cell surface proteins that bind IgG and facilitate cytokine production, phagocytosis, and Ab-dependent, cell-mediated cytotoxicity. FcγRs play a critical role in immunity; variation in these genes is implicated in autoimmunity and other diseases. Cynomolgus macaques are an excellent animal model for many human diseases, and Mauritian cynomolgus macaques (MCMs) are particularly useful because of their restricted genetic diversity. Previous studies of MCM immune gene diversity have focused on the MHC and killer cell Ig-like receptor. In this study, we characterize FcγR diversity in 48 MCMs using PacBio long-read sequencing to identify novel alleles of each of the four expressed MCM FcγR genes. We also developed a high-throughput FcγR genotyping assay, which we used to determine allele frequencies and identify FcγR haplotypes in more than 500 additional MCMs. We found three alleles for FcγR1A, seven each for FcγR2A and FcγR2B, and four for FcγR3A; these segregate into eight haplotypes. We also assessed whether different FcγR alleles confer different Ab-binding affinities by surface plasmon resonance and found minimal difference in binding affinities across alleles for a panel of wild type and Fc-engineered human IgG. This work suggests that although MCMs may not fully represent the diversity of FcγR responses in humans, they may offer highly reproducible results for mAb therapy and toxicity studies.


Assuntos
Genótipo , Macaca fascicularis , Receptores de IgG/genética , Alelos , Animais , Citotoxicidade Celular Dependente de Anticorpos , Frequência do Gene , Haplótipos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Imunidade , Imunoglobulina G/metabolismo , Modelos Animais , Ligação Proteica/genética , Receptores de IgG/metabolismo
5.
J Biomol NMR ; 68(4): 237-247, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28711957

RESUMO

An improved expression protocol is proposed for amino acid type-specific [13C], [15N]-isotope labeling of proteins in baculovirus-infected (BV) insect cell cultures. This new protocol modifies the methods published by Gossert et al. (J Biomol NMR 51(4):449-456, 2011) and provides efficient incorporation of isotopically labeled amino acids, with similar yields per L versus unlabeled expression in rich media. Gossert et al. identified the presence of unlabeled amino acids in the yeastolate of the growth medium as a major limitation in isotope labeling using BV-infected insect cells. By reducing the amount of yeastolate in the growth medium ten-fold, a significant improvement in labeling efficiency was demonstrated, while maintaining good protein expression yield. We report an alternate approach to improve isotope labeling efficiency using BV-infected insect cells namely by replacing the yeast extracts in the medium with dialyzed yeast extracts to reduce the amount of low molecular weight peptides and amino acids. We report the residual levels of amino acids in various media formulations and the amino acid consumption during fermentation, as determined by NMR. While direct replacement of yeastolate with dialyzed yeastolate delivered moderately lower isotope labeling efficiencies compared to the use of ten-fold diluted undialized yeastolate, we show that the use of dialyzed yeastolate combined with a ten-fold dilution delivered enhanced isotope labeling efficiency and at least a comparable level of protein expression yield, all at a scale which economizes use of these costly reagents.


Assuntos
Marcação por Isótopo/métodos , Aminoácidos/análise , Aminoácidos/química , Animais , Baculoviridae , Antígenos CD4/biossíntese , Antígenos CD4/química , Antígenos CD4/isolamento & purificação , Isótopos de Carbono , Meios de Cultura/análise , Meios de Cultura/química , Quinase 1 de Adesão Focal/biossíntese , Quinase 1 de Adesão Focal/química , Quinase 1 de Adesão Focal/isolamento & purificação , Isótopos de Nitrogênio , Ressonância Magnética Nuclear Biomolecular , Biossíntese de Proteínas , Células Sf9 , Spodoptera
6.
Mol Pharmacol ; 92(3): 310-317, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28645932

RESUMO

The NaV1.7 voltage-gated sodium channel is implicated in human pain perception by genetics. Rare gain of function mutations in NaV1.7 lead to spontaneous pain in humans whereas loss of function mutations results in congenital insensitivity to pain. Hence, agents that specifically modulate the function of NaV1.7 have the potential to yield novel therapeutics to treat pain. The complexity of the channel and the challenges to generate recombinant cell lines with high NaV1.7 expression have led to a surrogate target strategy approach employing chimeras with the bacterial channel NaVAb. In this report we describe the design, synthesis, purification, and characterization of a chimera containing part of the voltage sensor domain 2 (VSD2) of NaV1.7. Importantly, this chimera, DII S1-S4, forms functional sodium channels and is potently inhibited by the NaV1.7 VSD2 targeted peptide toxin ProTx-II. Further, we show by [125I]ProTx-II binding and surface plasmon resonance that the purified DII S1-S4 protein retains high affinity ProTx-II binding in detergent. We employed the purified DII S1-S4 protein to create a scintillation proximity assay suitable for high-throughput screening. The creation of a NaV1.7-NaVAb chimera with the VSD2 toxin binding site provides an important tool for the identification of novel NaV1.7 inhibitors and for structural studies to understand the toxin-channel interaction.


Assuntos
Proteínas de Bactérias/química , Canal de Sódio Disparado por Voltagem NAV1.7/fisiologia , Proteínas Recombinantes de Fusão/química , Venenos de Aranha/metabolismo , Canais de Sódio Disparados por Voltagem/química , Proteínas de Bactérias/fisiologia , Sítios de Ligação , Células HEK293 , Humanos , Ressonância de Plasmônio de Superfície , Canais de Sódio Disparados por Voltagem/fisiologia
7.
Acta Crystallogr D Struct Biol ; 72(Pt 5): 658-74, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27139629

RESUMO

The cytokine TGF-ß modulates a number of cellular activities and plays a critical role in development, hemostasis and physiology, as well as in diseases including cancer and fibrosis. TGF-ß signals through two transmembrane serine/threonine kinase receptors: TGFßR1 and TGFßR2. Multiple structures of the TGFßR1 kinase domain are known, but the structure of TGFßR2 remains unreported. Wild-type TGFßR2 kinase domain was refractory to crystallization, leading to the design of two mutated constructs: firstly, a TGFßR1 chimeric protein with seven ATP-site residues mutated to their counterparts in TGFßR2, and secondly, a reduction of surface entropy through mutation of six charged residues on the surface of the TGFßR2 kinase domain to alanines. These yielded apo and inhibitor-bound crystals that diffracted to high resolution (<2 Å). Comparison of these structures with those of TGFßR1 reveal shared ligand contacts as well as differences in the ATP-binding sites, suggesting strategies for the design of pan and selective TGFßR inhibitors.


Assuntos
Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/química , Receptores de Fatores de Crescimento Transformadores beta/antagonistas & inibidores , Receptores de Fatores de Crescimento Transformadores beta/química , Trifosfato de Adenosina/metabolismo , Sítios de Ligação , Cristalografia por Raios X , Humanos , Ligantes , Modelos Moleculares , Ligação Proteica , Isoformas de Proteínas/antagonistas & inibidores , Isoformas de Proteínas/química , Isoformas de Proteínas/metabolismo , Inibidores de Proteínas Quinases/química , Proteínas Serina-Treonina Quinases/metabolismo , Receptor do Fator de Crescimento Transformador beta Tipo I , Receptor do Fator de Crescimento Transformador beta Tipo II , Receptores de Fatores de Crescimento Transformadores beta/metabolismo
8.
Bioconjug Chem ; 27(5): 1276-84, 2016 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-27098672

RESUMO

A disulfide-bridged peptide drug development candidate contained two oligopeptide chains with 11 and 12 natural amino acids joined by a disulfide bond at the N-terminal end. An efficient biotechnology based process for the production of the disulfide-bridged peptide was developed. Initially, the two individual oligopeptide chains were prepared separately by designing different fusion proteins and expressing them in recombinant E. coli. Enzymatic or chemical cleavage of the two fusion proteins provided the two individual oligopeptide chains which could be conjugated via disulfide bond by conventional chemical reaction to the disulfide-bridged peptide. A novel heterodimeric system to bring the two oligopeptide chains closer and induce disulfide bond formation was designed by taking advantage of the self-assembly of a leucine zipper system. The heterodimeric approach involved designing fusion proteins with the acidic and basic components of the leucine zipper, additional amino acids to optimize interaction between the individual chains, specific cleavage sites, specific tag to ensure separation, and two individual oligopeptide chains. Computer modeling was used to identify the nature and number of amino acid residue to be inserted between the leucine zipper and oligopeptides for optimum interaction. Cloning and expression in rec E. coli, fermentation, followed by cell disruption resulted in the formation of heterodimeric protein with the interchain disulfide bond. Separation of the desired heterodimeric protein, followed by specific cleavage at methionine by cyanogen bromide provided the disulfide-bridged peptide.


Assuntos
Biotecnologia , Dissulfetos/química , Peptídeos/química , Peptídeos/metabolismo , Sequência de Aminoácidos , Escherichia coli/genética , Modelos Moleculares , Peptídeos/genética , Multimerização Proteica , Estrutura Quaternária de Proteína
9.
Acta Crystallogr F Struct Biol Commun ; 72(Pt 2): 129-34, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26841763

RESUMO

Microtubule-associated protein/microtubule affinity-regulating kinase 4 (MARK4) is a serine/threonine kinase involved in the phosphorylation of MAP proteins that regulate microtubule dynamics. Abnormal activity of MARK4 has been proposed to contribute to neurofibrillary tangle formation in Alzheimer's disease. The crystal structure of the catalytic and ubiquitin-associated domains of MARK4 with a potent pyrazolopyrimidine inhibitor has been determined to 2.8 Šresolution with an Rwork of 22.8%. The overall structure of MARK4 is similar to those of the other known MARK isoforms. The inhibitor is located in the ATP-binding site, with the pyrazolopyrimidine group interacting with the inter-lobe hinge region while the aminocyclohexane moiety interacts with the catalytic loop and the DFG motif, forcing the activation loop out of the ATP-binding pocket.


Assuntos
Cristalização/métodos , Cristalografia por Raios X/métodos , Proteínas Serina-Treonina Quinases/química , Proteínas Serina-Treonina Quinases/metabolismo , Pirazóis/química , Pirazóis/metabolismo , Pirimidinas/química , Pirimidinas/metabolismo , Sequência de Aminoácidos , Humanos , Dados de Sequência Molecular , Conformação Proteica , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/metabolismo
10.
J Mol Biol ; 427(4): 924-942, 2015 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-25579995

RESUMO

The human pregnane X receptor (PXR) is a promiscuous nuclear receptor that functions as a sensor to a wide variety of xenobiotics and regulates expression of several drug metabolizing enzymes and transporters. We have generated "Adnectins", derived from 10th fibronectin type III domain ((10)Fn3), that target the PXR ligand binding domain (LBD) interactions with the steroid receptor co-activator-1 (SRC-1) peptide, displacing SRC-1 binding. Adnectins are structurally homologous to the immunoglobulin superfamily. Three different co-crystal structures of PXR LBD with Adnectin-1 and CCR1 (CC chemokine receptor-1) antagonist Compound-1 were determined. This structural information was used to modulate PXR affinity for a related CCR1 antagonist compound that entered into clinical trials for rheumatoid arthritis. The structures of PXR with Adnectin-1 reveal specificity of Adnectin-1 in not only targeting the interface of the SRC-1 interactions but also engaging the same set of residues that are involved in binding of SRC-1 to PXR. Substituting SRC-1 with Adnectin-1 does not alter the binding conformation of Compound-1 in the ligand binding pocket. The structure also reveals the possibility of using Adnectins as crystallization chaperones to generate structures of PXR with compounds of interest.


Assuntos
Coativador 1 de Receptor Nuclear/química , Receptores CCR1/antagonistas & inibidores , Receptores de Esteroides/química , Ureia/análogos & derivados , Valina/análogos & derivados , Sequência de Aminoácidos , Sítios de Ligação , Cristalografia por Raios X , Humanos , Lignanas/metabolismo , Modelos Moleculares , Dados de Sequência Molecular , Receptor de Pregnano X , Ligação Proteica , Estrutura Terciária de Proteína , Receptores CCR1/metabolismo , Alinhamento de Sequência , Ressonância de Plasmônio de Superfície , Ureia/química , Ureia/metabolismo , Ureia/farmacologia , Valina/química , Valina/metabolismo , Valina/farmacologia
11.
J Pharmacol Exp Ther ; 350(2): 412-24, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24917546

RESUMO

Proprotein convertase subtilisin kexin-9 (PCSK9) is an important pharmacological target for decreasing low-density lipoprotein (LDL) in cardiovascular disease, although seemingly inaccessible to small molecule approaches. Compared with therapeutic IgG antibodies currently in development, targeting circulating PCSK9 with smaller molecular scaffolds could offer different profiles and reduced dose burdens. This inspired genesis of PCSK9-binding Adnectins, a protein family derived from human fibronectin-10th-type III-domain and engineered for high-affinity target binding. BMS-962476, an ∼11-kDa polypeptide conjugated to polyethylene glycol to enhance pharmacokinetics, binds with subnanomolar affinity to human. The X-ray cocrystal structure of PCSK9 with a progenitor Adnectin shows ∼910 Å(2) of PCSK9 surface covered next to the LDL receptor binding site, largely by residues of a single loop of the Adnectin. In hypercholesterolemic, overexpressing human PCSK9 transgenic mice, BMS-962476 rapidly lowered cholesterol and free PCSK9 levels. In genomic transgenic mice, BMS-962476 potently reduced free human PCSK9 (ED50 ∼0.01 mg/kg) followed by ∼2-fold increases in total PCSK9 before return to baseline. Treatment of cynomolgus monkeys with BMS-962476 rapidly suppressed free PCSK9 >99% and LDL-cholesterol ∼55% with subsequent 6-fold increase in total PCSK9, suggesting reduced clearance of circulating complex. Liver sterol response genes were consequently downregulated, following which LDL and total PCSK9 returned to baseline. These studies highlight the rapid dynamics of PCSK9 control over LDL and liver cholesterol metabolism and characterize BMS-962476 as a potent and efficacious PCSK9 inhibitor.


Assuntos
Anticolesterolemiantes/farmacologia , Lipoproteínas LDL/sangue , Polietilenoglicóis/farmacologia , Pró-Proteína Convertases/antagonistas & inibidores , Proteínas/farmacologia , Sequência de Aminoácidos , Animais , HDL-Colesterol/sangue , Cristalização , Feminino , Humanos , Macaca fascicularis , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Dados de Sequência Molecular , Pró-Proteína Convertase 9 , Pró-Proteína Convertases/química , Pró-Proteína Convertases/metabolismo , Ratos , Receptores de LDL/antagonistas & inibidores , Serina Endopeptidases/química , Serina Endopeptidases/metabolismo , Especificidade da Espécie
12.
Acta Crystallogr F Struct Biol Commun ; 70(Pt 2): 173-81, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24637750

RESUMO

Tau-tubulin kinase 1 (TTBK1) is a dual-specificity (serine/threonine and tyrosine) kinase belonging to the casein kinase 1 superfamily. TTBK1 is a neuron-specific kinase that regulates tau phosphorylation. Hyperphosphorylation of tau is implicated in the pathogenesis of Alzheimer's disease. Two kinase-domain constructs of TTBK1 were expressed in a baculovirus-infected insect-cell system and purified. The purified TTBK1 kinase-domain proteins were crystallized using the hanging-drop vapor-diffusion method. X-ray diffraction data were collected and the structure of TTBK1 was determined by molecular replacement both as an apo structure and in complex with a kinase inhibitor.


Assuntos
Inibidores de Proteínas Quinases/química , Proteínas Serina-Treonina Quinases/química , Animais , Baculoviridae/genética , Cristalização , Cristalografia por Raios X , Eletroforese em Gel de Poliacrilamida , Humanos , Espectroscopia de Ressonância Magnética , Conformação Proteica , Células Sf9 , Especificidade por Substrato
13.
Assay Drug Dev Technol ; 12(1): 80-6, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24547742

RESUMO

Receptor tyrosine kinases (RTKs) regulate a wide range of important biological activities, including cell proliferation, differentiation, migration, and apoptosis. Abnormalities in RTKs are involved in numerous diseases, including cancer and other proliferative disorders. AXL belongs to the TAM (Tyso3, AXL, and Mer) family of RTKs. The AXL signaling pathway represents an attractive target for the treatment of diseases, such as cancer. Using phospho-AKT as readout, a high-throughput 384-well cell-based assay was established in the NCI-H1299 human non-small cell lung carcinoma cell line to evaluate compound potency in inhibiting AXL pathway activation. In addition, a counter screen assay was established in the same cellular background to differentiate AXL kinase inhibitors from AXL receptor antagonists, which block the interaction of AXL and its natural ligand GAS6. These cell-based functional assays are useful tools in the identification and optimization of small molecules and biological reagents for potential therapeutics for the treatment of GAS6/AXL-related diseases.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/metabolismo , Ensaios de Triagem em Larga Escala/métodos , Interpretação de Imagem Assistida por Computador/métodos , Neoplasias Pulmonares/metabolismo , Inibidores de Proteínas Quinases/administração & dosagem , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Proteínas Proto-Oncogênicas/metabolismo , Receptores Proteína Tirosina Quinases/antagonistas & inibidores , Receptores Proteína Tirosina Quinases/metabolismo , Bioensaio/métodos , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Desenho de Fármacos , Avaliação Pré-Clínica de Medicamentos/métodos , Humanos , Neoplasias Pulmonares/patologia , Microscopia de Fluorescência/métodos , Imagem Molecular/métodos , Transdução de Sinais/efeitos dos fármacos
14.
J Med Chem ; 57(5): 1855-79, 2014 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-24397558

RESUMO

Described herein are structure-activity relationship studies that resulted in the optimization of the activity of members of a class of cyclopropyl-fused indolobenzazepine HCV NS5B polymerase inhibitors. Subsequent iterations of analogue design and syntheses successfully addressed off-target activities, most notably human pregnane X receptor (hPXR) transactivation, and led to significant improvements in the physicochemical properties of lead compounds. Those analogues exhibiting improved solubility and membrane permeability were shown to have notably enhanced pharmacokinetic profiles. Additionally, a series of alkyl bridged piperazine carboxamides was identified as being of particular interest, and from which the compound BMS-791325 (2) was found to have distinguishing antiviral, safety, and pharmacokinetic properties that resulted in its selection for clinical evaluation.


Assuntos
Antivirais/farmacologia , Benzazepinas/farmacologia , Inibidores Enzimáticos/farmacologia , Indóis/farmacologia , Proteínas não Estruturais Virais/antagonistas & inibidores , Regulação Alostérica , Animais , Antivirais/química , Antivirais/farmacocinética , Benzazepinas/química , Benzazepinas/farmacocinética , Cães , Descoberta de Drogas , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacocinética , Humanos , Indóis/química , Indóis/farmacocinética , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Modelos Moleculares , Ratos , Relação Estrutura-Atividade
15.
J Biomol Screen ; 18(9): 1072-83, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24062352

RESUMO

Transporter proteins are known to play a critical role in affecting the overall absorption, distribution, metabolism, and excretion characteristics of drug candidates. In addition to efflux transporters (P-gp, BCRP, MRP2, etc.) that limit absorption, there has been a renewed interest in influx transporters at the renal (OATs, OCTs) and hepatic (OATPs, BSEP, NTCP, etc.) organ level that can cause significant clinical drug-drug interactions (DDIs). Several of these transporters are also critical for hepatobiliary disposition of bilirubin and bile acid/salts, and their inhibition is directly implicated in hepatic toxicities. Regulatory agencies took action to address transporter-mediated DDI with the goal of ensuring drug safety in the clinic and on the market. To meet regulatory requirements, advanced bioassay technology and automation solutions were implemented for high-throughput transporter screening to provide structure-activity relationship within lead optimization. To enhance capacity, several functional assay formats were miniaturized to 384-well throughput including novel fluorescence-based uptake and efflux inhibition assays using high-content image analysis as well as cell-based radioactive uptake and vesicle-based efflux inhibition assays. This high-throughput capability enabled a paradigm shift from studying transporter-related issues in the development space to identifying and dialing out these concerns early on in discovery for enhanced mechanism-based efficacy while circumventing DDIs and transporter toxicities.


Assuntos
Descoberta de Drogas , Drogas em Investigação/farmacologia , Ensaios de Triagem em Larga Escala , Proteínas de Membrana Transportadoras/metabolismo , Transporte Biológico/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Aprovação de Drogas , Avaliação Pré-Clínica de Medicamentos , Interações Medicamentosas , Drogas em Investigação/química , Drogas em Investigação/metabolismo , Corantes Fluorescentes , Humanos , Rim/efeitos dos fármacos , Rim/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Proteínas de Membrana Transportadoras/química , Relação Estrutura-Atividade
16.
Bioanalysis ; 5(11): 1363-76, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23742306

RESUMO

BACKGROUND: There is a need for general and reliable LC-MS assays capable of supporting the bioanalysis of a variety of human monoclonal antibody-based therapeutic drug candidates in animal PK/TK studies. RESULTS: We present herein improvements in our previously reported universal peptide approach to the bioanalysis of human monoclonal antibody protein drug candidates in animal studies. These improvements include incorporation of a second, light chain-based universal peptide into the assay, thus introducing the concept of a dual universal peptide assay; and incorporation of a universal stable isotope-labeled monoclonal antibody into the assay. CONCLUSION: Improvements reported herein to the universal peptide assay will enable more reliable quantification of human monoclonal antibody protein drug candidates in animal studies.


Assuntos
Anticorpos Monoclonais/farmacocinética , Cromatografia Líquida/métodos , Peptídeos/análise , Espectrometria de Massas em Tandem/métodos , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais/análise , Haplorrinos , Humanos , Marcação por Isótopo , Dados de Sequência Molecular
17.
J Med Chem ; 54(19): 6548-62, 2011 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-21882820

RESUMO

Protein tyrosine phosphatases (PTPs) catalyze the dephosphorylation of tyrosine residues, a process that involves a conserved tryptophan-proline-aspartate (WPD) loop in catalysis. In previously determined structures of PTPs, the WPD-loop has been observed in either an "open" conformation or a "closed" conformation. In the current work, X-ray structures of the catalytic domain of receptor-like protein tyrosine phosphatase γ (RPTPγ) revealed a ligand-induced "superopen" conformation not previously reported for PTPs. In the superopen conformation, the ligand acts as an apparent competitive inhibitor and binds in a small hydrophobic pocket adjacent to, but distinct from, the active site. In the open and closed WPD-loop conformations of RPTPγ, the side chain of Trp1026 partially occupies this pocket. In the superopen conformation, Trp1026 is displaced allowing a 3,4-dichlorobenzyl substituent to occupy this site. The bound ligand prevents closure of the WPD-loop over the active site and disrupts the catalytic cycle of the enzyme.


Assuntos
Modelos Moleculares , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/antagonistas & inibidores , Tiofenos/química , Sequência de Aminoácidos , Domínio Catalítico , Cristalografia por Raios X , Humanos , Interações Hidrofóbicas e Hidrofílicas , Ligantes , Dados de Sequência Molecular , Ligação Proteica , Conformação Proteica , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/química , Relação Estrutura-Atividade , Tiofenos/síntese química
18.
Chem Biol Drug Des ; 78(5): 739-48, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21883956

RESUMO

Bone marrow kinase in the X chromosome, a member of the Tec family of tyrosine kinases, plays a role in both monocyte/macrophage trafficking as well as cytokine secretion. Although the structures of Tec family kinases Bruton's tyrosine kinase and IL-2-inducible T-cell kinase are known, the crystal structures of other Tec family kinases have remained elusive. We report the X-ray crystal structures of bone marrow kinase in the X chromosome in complex with dasatinib at 2.4 Å resolution and PP2 at 1.9 Å resolution. The bone marrow kinase in the X chromosome structures reveal a typical kinase protein fold; with well-ordered protein conformation that includes an open/extended activation loop and a stabilized DFG-motif rendering the kinase in an inactive conformation. Dasatinib and PP2 bind to bone marrow kinase in the X chromosome in the ATP binding pocket and display similar binding modes to that observed in other Tec and Src protein kinases. The bone marrow kinase in the X chromosome structures identify conformational elements of the DFG-motif that could potentially be utilized to design potent and/or selective bone marrow kinase in the X chromosome inhibitors.


Assuntos
Cromossomos Humanos X , Proteínas Tirosina Quinases/química , Tirosina Quinase da Agamaglobulinemia , Sítios de Ligação , Cristalografia por Raios X , Dasatinibe , Humanos , Ligação Proteica , Inibidores de Proteínas Quinases/química , Estrutura Terciária de Proteína , Proteínas Tirosina Quinases/metabolismo , Pirimidinas/química , Tiazóis/química , Quinases da Família src/química , Quinases da Família src/metabolismo
19.
Artigo em Inglês | MEDLINE | ID: mdl-21795790

RESUMO

Protein tyrosine phosphatase γ is a membrane-bound receptor and is designated RPTPγ. RPTPγ and two mutants, RPTPγ(V948I, S970T) and RPTPγ(C858S, S970T), were recombinantly expressed and purified for X-ray crystallographic studies. The purified enzymes were crystallized using the hanging-drop vapor-diffusion method. Crystallographic data were obtained from several different crystal forms in the absence and the presence of inhibitor. In this paper, a description is given of how three different crystal forms were obtained that were used with various ligands. An orthorhombic crystal form and a trigonal crystal form were obtained both with and without ligand, and a monoclinic crystal form was only obtained in the presence of a particularly elaborated inhibitor.


Assuntos
Domínio Catalítico , Proteínas Tirosina Fosfatases Semelhantes a Receptores/química , Sequência de Aminoácidos , Clonagem Molecular , Cristalização , Cristalografia por Raios X , Humanos , Dados de Sequência Molecular , Proteínas Tirosina Fosfatases Semelhantes a Receptores/genética , Proteínas Tirosina Fosfatases Semelhantes a Receptores/isolamento & purificação
20.
Virology ; 388(1): 103-11, 2009 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-19339032

RESUMO

The Rev protein of HIV-1 is essential for HIV-1 proliferation due to its role in exporting viral RNA from the nucleus. We used a modified version of tandem affinity purification (TAP) tagging to identify proteins interacting with HIV-1 Rev in human cells and discovered a prominent interaction between Rev and nucleosome assembly protein 1 (Nap1). This interaction was also observed by specific retention of Nap1 from human cell lysates on a Rev affinity column. Nap1 was found to bind Rev through the Rev arginine-rich domain and altered the oligomerization state of Rev in vitro. Overexpression of Nap1 stimulated the ability of Rev to export RNA, reduced the nucleolar localization of Rev, and affected Rev nuclear import rates. The results suggest that Nap-1 may influence Rev function by increasing the availability of Rev.


Assuntos
Proteínas/metabolismo , Produtos do Gene rev do Vírus da Imunodeficiência Humana/metabolismo , Sistema Livre de Células , Cromatografia de Afinidade , Células HeLa , Humanos , Produtos do Gene rev do Vírus da Imunodeficiência Humana/genética , tRNA Metiltransferases
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