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2.
Carbohydr Polym ; 337: 122163, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-38710557

RESUMEN

Prion diseases are fatal transmissible neurodegenerative disorders. Among known anti-prions, hydroxypropyl methylcellulose compounds (HPMCs) are unique in their chemical structure and action. They have several excellent anti-prion properties but the effectiveness depends on the prion-infected mouse model. In the present study, we investigated the effects of stearoxy-modified HPMCs on prion-infected cells and mice. Stearoxy modification improved the anti-prion efficacy of HPMCs in prion-infected cells and significantly prolonged the incubation period in a lower HPMC-responding mouse model. However, stearoxy modification showed no improvement over nonmodified HPMCs in an HPMC-responding mouse model. These results offer a new line of inquiry for use with prion-infected mice that do not respond well to HPMCs.


Asunto(s)
Derivados de la Hipromelosa , Enfermedades por Prión , Animales , Derivados de la Hipromelosa/química , Ratones , Enfermedades por Prión/tratamiento farmacológico , Modelos Animales de Enfermedad
3.
Mol Neurobiol ; 2023 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-38114760

RESUMEN

Prion diseases are fatal transmissible neurodegenerative disorders. Tremendous efforts have been made for prion diseases; however, no effective treatment is available. Several anti-prion compounds have a preference for which prion strains or prion-infected animal models to target. Styrylbenzoazole compound called cpd-B is effective in RML prion-infected mice but less so in 263K prion-infected mice, whereas hydroxypropyl methylcellulose is effective in 263K prion-infected mice but less so in RML prion-infected mice. In the present study, we developed a combination therapy of cpd-B and hydroxypropyl methylcellulose expecting synergistic effects in both RML prion-infected mice and 263K prion-infected mice. A single subcutaneous administration of this combination had substantially a synergistic effect in RML prion-infected mice but had no additive effect in 263K prion-infected mice. These results showed that the effect of cpd-B was enhanced by hydroxypropyl methylcellulose. The complementary nature of the two compounds in efficacy against prion strains, chemical properties, pharmacokinetics, and physical properties appears to have contributed to the effective combination therapy. Our results pave the way for the strategy of new anti-prion agents.

4.
Heliyon ; 9(3): e13974, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36915552

RESUMEN

The polymorphic heterozygosity of PRNP at codon 129 or 219 prevents the onset of sporadic Creutzfeldt-Jakob disease (sCJD). We investigated the association between polymorphic genotypes at codon 129 or 219 and comprehensive prion disease onset using non-CJD as a reference. EK heterozygotes at codon 219, versus EE homozygotes, showed a preventive effect on the extensive prion diseases-sCJD, genetic CJD (gCJD) with V180I or M232R mutation, and Gerstmann-Straussler-Scheinker disease with P102L mutation. No preventive effect was observed for E200K-gCJD and dura-grafted CJD (dCJD) in 129 MV and 219 EK heterozygotes. It was suggested that unlike other prion diseases, E200K-gCJD may not benefit from the preventive effect of 219 EK heterozygosity because complementary electrostatic interactions between PrP molecules at K200 and E219 might make homodimer formation easier. Comparison of sCJD and dCJD indicates that 219 EK heterozygosity strongly inhibits de novo synthesis of PrPSc (initial PrPSc formation), but does not inhibit accelerated propagation of existing PrPSc.

5.
Cell Tissue Res ; 392(1): 349-365, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35307792

RESUMEN

Prion diseases, also known as transmissible spongiform encephalopathies, are caused by the accumulation of abnormal isoforms of the prion protein (scrapie isoform of the prion protein, PrPSc) in the central nervous system. Many compounds with anti-prion activities have been found using in silico screening, in vitro models, persistently prion-infected cell models, and prion-infected rodent models. Some of these compounds include several types of polymers. Although the inhibition or removal of PrPSc production is the main target of therapy, the unique features of prions, namely protein aggregation and assembly accompanied by steric structural transformation, may require different strategies for the development of anti-prion drugs than those for conventional therapeutics targeting enzyme inhibition, agonist ligands, or modulation of signaling. In this paper, we first overview the history of the application of polymers to prion disease research. Next, we describe the characteristics of each type of polymer with anti-prion activity. Finally, we discuss the common features of these polymers. Although drug delivery of these polymers to the brain is a challenge, they are useful not only as leads for therapeutic drugs but also as tools to explore the structure of PrPSc and are indispensable for prion disease research.


Asunto(s)
Enfermedades por Prión , Priones , Scrapie , Animales , Ovinos , Proteínas Priónicas , Polímeros , Enfermedades por Prión/tratamiento farmacológico
6.
Molecules ; 27(5)2022 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-35268749

RESUMEN

In this study, the effects of side-chain configurations of D-Ile residues of a retro-inverso (RI)-type inhibitor on the human T-cell leukemia virus type 1 (HTLV-1) protease containing a hydroxyethylamine dipeptide isostere were clarified. Prior to evaluation using the RI-type inhibitor, the effects of side-chain configurations of Ile residues of the substrate peptide on the HTLV-1 protease were examined to estimate the influence of side-chain configurations on enzyme activity. Based on the estimation of the influence of side-chain configurations on protease affinity, the RI-type inhibitors containing a D-allo-Ile residue in the corresponding substrate sequence, instead of a D-Ile residue, were synthesized via 9-fluorenylmethoxycarbonyl-based solid-phase peptide synthesis. Refolded recombinant HTLV-1 protease (1-116, L40I) was used for the simple and short evaluation of the inhibitory activities of the synthesized RI-type inhibitors. The results clearly indicated that mimicking the whole topology, comprising both the main- and side-chain structures of the parent inhibitor, is effective for the design of potent RI-modified protease inhibitors.


Asunto(s)
Péptido Hidrolasas
7.
Int Immunopharmacol ; 107: 108672, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35279511

RESUMEN

The anti-prion activity of cellulose ether (CE) has been reported in rodents, but the mechanism of action is not well understood. As defects in early T-cell development have been reported in Tga20 mice which show only a slight effect of CE administration, we investigated the involvement of immune functions in the CE action. We confirmed an insertion of the prion protein transgene into the pre T-cell antigen receptor α gene of Tga20 mice, and its impaired expression in the thymus and other tissues. The influence of immune suppression on the CE effect was then examined in high CE-responder mice treated with immunosuppressive agents or neonatal thymectomy. As neonatal thymectomy significantly reduced the CE effect, we compared the influence of various T-cell defects in mice with similar genetic backgrounds. The CE effect was increased or unchanged in mice with defects in the αß T-cell lineage, whereas it was abolished in T-cell receptor δ deficient mice. Further, when other immune defects were examined, the CE effect was reduced in mice with lysosomal trafficking dysfunction, but was unchanged in mice deficient in B-cell differentiation or toll-like receptor 4 signaling. These findings collectively suggest that the mechanism of CE action may involve γδ T cells and lytic granule function, as well as immune factors like natural killer T cells which are lacking in pre T-cell antigen receptor α deficient mice and neonatally thymectomized mice.


Asunto(s)
Priones , Animales , Celulosa , Éter , Éteres , Ratones , Ratones Endogámicos C57BL , Receptores de Antígenos de Linfocitos T alfa-beta/genética , Receptores de Antígenos de Linfocitos T gamma-delta
8.
Biochim Biophys Acta Gen Subj ; 1866(4): 130094, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35065183

RESUMEN

BACKGROUND: Cultured cell lines infected with prions produce an abnormal isoform of the prion protein (PrPSc). In this study, two types of cells persistently infected with prion were treated with curcumin-related compounds. We found that the compounds behave differently in neuroblastoma neuro-2a (N2a) cells infected with different prion strains. METHODS: Curcumin and related compounds were applied to the two types of persistently prion infected cells to analyze the different activities of the compounds. RESULTS: In ScN2a cells, which were infected with the Rocky Mountain Laboratory prion strain, two of the six compounds significantly reduced the PrPSc level in a dose-dependent manner. On the other hand, in N167 cells, effective suppression of the total amount of PrPSc was not observed; instead, two other compounds promoted the formation of covalently linked PrPSc dimers. CONCLUSIONS: Chemometric analysis was used to determine the factors that contributed to the different effects of the six compounds. It showed that the ability to form hydrogen bonds, such as phenolic hydroxyl groups, and hydrophobic molecular properties predominantly contributed to the reduction of the PrPSc level in the ScN2a cells and the dimer formation of PrPSc in the N167 cells, respectively. GENERAL SIGNIFICANCE: The extracted information can be used to delineate the differences among prion strains and to design compounds that are directed toward their respective activities.


Asunto(s)
Curcumina , Priones , Línea Celular , Curcumina/farmacología , Proteínas PrPSc/metabolismo , Proteínas Priónicas , Priones/química , Priones/metabolismo
9.
Biochem Biophys Res Commun ; 560: 105-111, 2021 06 30.
Artículo en Inglés | MEDLINE | ID: mdl-33984767

RESUMEN

Anti-prion effects of cellulose ether (CE) are reported in rodents, but the molecular mechanism is fully unknown. Here, we investigated the genetic background of CE effectiveness by proteomic and genetic analysis in mice. Proteomic analysis in the two mouse lines showing a dramatic difference in CE effectiveness revealed a distinct polymorphism in the glia maturation factor ß gene. This polymorphism was significantly associated with the CE effectiveness in various prion-infected mouse lines. Sequencing of this gene and its vicinity genes also revealed several other polymorphisms that were significantly related to the CE effectiveness. These polymorphisms are useful as genetic markers for finding more suitable mouse lines and exploring the genetic factors of CE effectiveness.


Asunto(s)
Factor de Maduración de la Glia/genética , Derivados de la Hipromelosa/uso terapéutico , Enfermedades por Prión/tratamiento farmacológico , Animales , Encéfalo/metabolismo , Marcadores Genéticos , Genómica , Masculino , Ratones , Polimorfismo Genético , Enfermedades por Prión/genética , Enfermedades por Prión/metabolismo , Proteómica
10.
Mol Neurobiol ; 58(9): 4280-4292, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33983547

RESUMEN

Previous studies have revealed that the infectious scrapie isoform of prion protein (PrPSc) harbored in the skin tissue of patients or animals with prion diseases can be amplified and detected through the serial protein misfolding cyclic amplification (sPMCA) or real-time quaking-induced conversion (RT-QuIC) assays. These findings suggest that skin PrPSc-seeding activity may serve as a biomarker for the diagnosis of prion diseases; however, its utility as a biomarker for prion therapeutics remains largely unknown. Cellulose ethers (CEs, such as TC-5RW), widely used as food and pharmaceutical additives, have recently been shown to prolong the lifespan of prion-infected mice and hamsters. Here we report that in transgenic (Tg) mice expressing hamster cellular prion protein (PrPC) infected with the 263K prion, the prion-seeding activity becomes undetectable in the skin tissues of TC-5RW-treated Tg mice by both sPMCA and RT-QuIC assays, whereas such prion-seeding activity is readily detectable in the skin of untreated mice. Notably, TC-5RW exhibits an inhibitory effect on the in vitro amplification of PrPSc in both skin and brain tissues by sPMCA and RT-QuIC. Moreover, we reveal that TC-5RW is able to directly decrease protease-resistant PrPSc and inhibit the seeding activity of PrPSc from chronic wasting disease and various human prion diseases. Our results suggest that the level of prion-seeding activity in the skin may serve as a useful biomarker for assessing the therapeutic efficacy of compounds in a clinical trial of prion diseases and that TC-5RW may have the potential for the prevention/treatment of human prion diseases.


Asunto(s)
Proteínas PrPSc/metabolismo , Enfermedades por Prión/metabolismo , Piel/metabolismo , Animales , Biomarcadores , Encéfalo/metabolismo , Encéfalo/patología , Ratones , Ratones Transgénicos , Enfermedades por Prión/patología
11.
J Pharm Sci ; 108(8): 2814-2820, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-30914271

RESUMEN

Prion accumulation in the brain and lymphoreticular system causes fatal neurodegenerative diseases. Our previous study revealed that cellulose ethers (CE) have anti-prion activities in vivo and in prion-infected cells when administered at high doses. This study aims to improve the bioavailability of a representative CE using a liposomal formulation and characterized CE-loaded liposomes in cultured cells. The liposomal formulation reduced the EC50 dose of CE by <1/200-fold in prion-infected cells. Compared to empty liposomes, CE-loaded liposomes were taken up much more highly by prion-infected cells and less by macrophage-like cells. Phosphatidylserine modification reduced the uptake of CE-loaded liposomes in prion-infected cells and did not change the anti-prion activity, whereas increased the uptake in macrophage-like cells. Polyethylene glycol modification reduced the uptake of CE-loaded liposomes in both types of cells and reduced the anti-prion activity in prion-infected cells. These results suggest that a liposomal formulation of CE is more practical than unformulated CE and showed that the CE-loaded liposome uptake levels in prion-infected cells were not associated with anti-prion activity. Although further improvement of the stealth function against phagocytic cells is needed, the liposomal formulation is useful to improve CE efficacy and elucidate the mechanism of CE action.


Asunto(s)
Celulosa/administración & dosificación , Éteres/administración & dosificación , Liposomas/química , Priones/antagonistas & inhibidores , Animales , Línea Celular , Celulosa/farmacocinética , Celulosa/farmacología , Éteres/farmacocinética , Éteres/farmacología , Humanos , Ratones , Fosfatidilserinas/química , Polietilenglicoles/química , Células RAW 264.7
12.
Biochim Biophys Acta Gen Subj ; 1863(2): 384-394, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30447252

RESUMEN

In prion diseases, infectious pathogenic particles that are composed of abnormal prion proteins (PrPSc) accumulate in the brain. PrPSc is biochemically characterized by its protease-resistance core (PrPres), but its structural features have not been fully elucidated. Here, we report that primuline, a fluorescent dye with photosensitization activity, dramatically enhances UV-irradiation-induced SDS-resistant PrPSc/res oligomer formation that can be detected by immunoblot analysis of prion-infected materials. This oligomer formation occurs specifically with PrPSc/res but not with normal prion protein, and it was demonstrated using purified PrPSc/res as well as unpurified materials. The oligomer formation proceeded in both primuline-dose- and UV irradiation time-dependent manners. Treatment with urea or formic acid did not break oligomers into monomers. Neither did the presence of aromatic amino acids modify oligomer formation. Analysis with a panel of anti-prion protein antibodies showed that the antibodies against the N-terminal region of PrPres were less reactive in the dimer than the monomer. These findings suggest that the primuline-sensitized photoreaction enhances intermolecular crosslinking of PrPSc/res molecules at a hydrophobic area of the N-terminal region of PrPres. In the screening of other compounds, photoreactive compounds such as luciferin exhibited a similar but lower activity with respect to oligomer formation than primuline. The enhanced photoreaction with these compounds will be useful for evaluating the structural features of PrPSc/res, especially the interactions between PrPSc/res molecules.


Asunto(s)
Fármacos Fotosensibilizantes/química , Enfermedades por Prión/metabolismo , Enfermedades por Prión/patología , Proteínas Priónicas/química , Tiazoles/química , Rayos Ultravioleta , Animales , Anticuerpos/inmunología , Encéfalo/metabolismo , Encéfalo/patología , Línea Celular Tumoral , Relación Dosis-Respuesta a Droga , Ratones , Ratones Endogámicos ICR , Proteínas Priónicas/análisis , Proteínas Priónicas/inmunología , Proteínas Priónicas/metabolismo , Factores de Tiempo
13.
PLoS One ; 12(9): e0185357, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28934337

RESUMEN

Our previous study on prion-infected rodents revealed that hydroxypropyl methylcellulose compounds (HPMCs) with different molecular weights but similar composition and degree of substitution have different levels of long-lasting anti-prion activity. In this study, we searched these HPMCs for a parameter specifically associated with in vivo anti-prion activity by analyzing in vitro chemical properties and in vivo tissue distributions. Infrared spectroscopic and thermal analyses revealed no differences among HPMCs, whereas pyrene conjugation and spectroscopic analysis revealed that the fluorescence intensity ratio of peak III/peak I correlated with anti-prion activity. This correlation was more clearly demonstrated in the anti-prion activity of the 1-year pre-infection treatment than that of the immediate post-infection treatment. In addition, the intensity ratio of peak III/peak I negatively correlated with the macrophage uptake level of HPMCs in our previous study. However, the in vivo distribution pattern was apparently not associated with anti-prion activity and was different in the representative tissues. These findings suggest that pyrene conjugation and spectroscopic analysis are powerful methods to successfully demonstrate local dielectric differences in HPMCs and provide a feasible parameter denoting the long-lasting anti-prion activity of HPMCs in vivo.


Asunto(s)
Derivados de la Hipromelosa/química , Derivados de la Hipromelosa/farmacología , Proteínas Priónicas/antagonistas & inhibidores , Pirenos/química , Animales , Transporte Biológico , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Impedancia Eléctrica , Derivados de la Hipromelosa/metabolismo , Derivados de la Hipromelosa/farmacocinética , Macrófagos/metabolismo , Ratones , Peso Molecular , Proteínas Priónicas/metabolismo , Espectroscopía Infrarroja por Transformada de Fourier , Bazo/efectos de los fármacos , Bazo/metabolismo , Relación Estructura-Actividad , Distribución Tisular
14.
Bioorg Med Chem Lett ; 27(12): 2746-2751, 2017 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-28454669

RESUMEN

Synthesis and evaluation of new scaffold phenylisoserine derivatives connected with the essential functional groups against SARS CoV 3CL protease are described. The phenylisoserine backbone was found by simulation on GOLD software and the structure activity relationship study of phenylisoserine derivatives gave SK80 with an IC50 value of 43µM against SARS CoV 3CL R188I mutant protease.


Asunto(s)
Inhibidores de Proteasas/farmacología , Serina/análogos & derivados , Proteínas Virales/antagonistas & inhibidores , Proteasas 3C de Coronavirus , Cisteína Endopeptidasas/genética , Cisteína Endopeptidasas/metabolismo , Relación Dosis-Respuesta a Droga , Humanos , Modelos Moleculares , Estructura Molecular , Inhibidores de Proteasas/síntesis química , Inhibidores de Proteasas/química , Serina/síntesis química , Serina/química , Serina/farmacología , Relación Estructura-Actividad , Proteínas Virales/genética , Proteínas Virales/metabolismo
15.
J Virol ; 91(6)2017 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-28077650

RESUMEN

Prion diseases are progressive fatal neurodegenerative illnesses caused by the accumulation of transmissible abnormal prion protein (PrP). To find treatments for prion diseases, we searched for substances from natural resources that inhibit abnormal PrP formation in prion-infected cells. We found that high-molecular-weight components from insect cuticle extracts reduced abnormal PrP levels. The chemical nature of these components was consistent with that of melanin. In fact, synthetic melanin produced from tyrosine or 3-hydroxy-l-tyrosine inhibited abnormal PrP formation. Melanin did not modify cellular or cell surface PrP levels, nor did it modify lipid raft or cellular cholesterol levels. Neither did it enhance autophagy or lysosomal function. Melanin was capable of interacting with PrP at two N-terminal domains. Specifically, it strongly interacted with the PrP region of amino acids 23 to 50 including a positively charged amino acid cluster and weakly interacted with the PrP octarepeat peptide region of residues 51 to 90. However, the in vitro and in vivo data were inconsistent with those of prion-infected cells. Abnormal PrP formation in protein misfolding cyclic amplification was not inhibited by melanin. Survival after prion infection was not significantly altered in albino mice or exogenously melanin-injected mice compared with that of control mice. These data suggest that melanin, a main determinant of skin color, is not likely to modify prion disease pathogenesis, even though racial differences in the incidence of human prion diseases have been reported. Thus, the findings identify an interaction between melanin and the N terminus of PrP, but the pathophysiological roles of the PrP-melanin interaction remain unclear.IMPORTANCE The N-terminal region of PrP is reportedly important for neuroprotection, neurotoxicity, and abnormal PrP formation, as this region is bound by many factors, such as metal ions, lipids, nucleic acids, antiprion compounds, and several proteins, including abnormal PrP in prion disease and the Aß oligomer in Alzheimer's disease. In the present study, melanin, a main determinant of skin color, was newly found to interact with this N-terminal region and inhibits abnormal PrP formation in prion-infected cells. However, the data for prion infection in mice lacking melanin production suggest that melanin is not associated with the prion disease mechanism, although the incidence of prion disease is reportedly much higher in white people than in black people. Thus, the roles of the PrP-melanin interaction remain to be further elucidated, but melanin might be a useful competitive tool for evaluating the functions of other ligands at the N-terminal region.


Asunto(s)
Melaninas/metabolismo , Enfermedades por Prión/prevención & control , Priones/metabolismo , Animales , Línea Celular , Melaninas/administración & dosificación , Ratones , Neuronas/metabolismo , Enfermedades por Prión/tratamiento farmacológico , Unión Proteica , Mapeo de Interacción de Proteínas , Análisis de Supervivencia
16.
Artículo en Inglés | MEDLINE | ID: mdl-27836910

RESUMEN

Although an effective therapy for prion disease has not yet been established, many advances have been made toward understanding its pathogenesis, which has facilitated research into therapeutics for the disease. Several compounds, including flupirtine, quinacrine, pentosan polysulfate, and doxycycline, have recently been used on a trial basis for patients with prion disease. Concomitantly, several lead antiprion compounds, including compound B (compB), IND series, and anle138b, have been discovered. However, clinical trials are still far from yielding significantly beneficial results, and the findings of lead compound studies in animals have highlighted new challenges. These efforts have highlighted areas that need improvement or further exploration to achieve more effective therapies. In this work, we review recent advances in prion-related therapeutic research and discuss basic scientific issues to be resolved for meaningful medical intervention of prion disease.


Asunto(s)
Síndrome de Creutzfeldt-Jakob/diagnóstico , Síndrome de Creutzfeldt-Jakob/tratamiento farmacológico , Síndrome de Creutzfeldt-Jakob/historia , Aminopiridinas/uso terapéutico , Animales , Modelos Animales de Enfermedad , Doxiciclina/uso terapéutico , Descubrimiento de Drogas , Historia del Siglo XX , Historia del Siglo XXI , Humanos , Poliéster Pentosan Sulfúrico/uso terapéutico , Quinacrina/uso terapéutico , Ensayos Clínicos Controlados Aleatorios como Asunto , Investigación Biomédica Traslacional
17.
PLoS Pathog ; 12(12): e1006045, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27973536

RESUMEN

Prion diseases are fatal, progressive, neurodegenerative diseases caused by prion accumulation in the brain and lymphoreticular system. Here we report that a single subcutaneous injection of cellulose ethers (CEs), which are commonly used as inactive ingredients in foods and pharmaceuticals, markedly prolonged the lives of mice and hamsters intracerebrally or intraperitoneally infected with the 263K hamster prion. CEs provided sustained protection even when a single injection was given as long as one year before infection. These effects were linked with persistent residues of CEs in various tissues. More effective CEs had less macrophage uptake ratios and hydrophobic modification of CEs abolished the effectiveness. CEs were significantly effective in other prion disease animal models; however, the effects were less remarkable than those observed in the 263K prion-infected animals. The genetic background of the animal model was suggested to influence the effects of CEs. CEs did not modify prion protein expression but inhibited abnormal prion protein formation in vitro and in prion-infected cells. Although the mechanism of CEs in vivo remains to be solved, these findings suggest that they aid in elucidating disease susceptibility and preventing prion diseases.


Asunto(s)
Derivados de la Hipromelosa/farmacología , Enfermedades por Prión/patología , Animales , Celulosa/farmacología , Cricetinae , Modelos Animales de Enfermedad , Éteres/farmacología , Inyecciones Subcutáneas , Masculino , Mesocricetus , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos
18.
Biopolymers ; 106(4): 391-403, 2016 Nov 04.
Artículo en Inglés | MEDLINE | ID: mdl-26572934

RESUMEN

Design of inhibitors against severe acute respiratory syndrome (SARS) chymotrypsin-like protease (3CL(pro) ) is a potentially important approach to fight against SARS. We have developed several synthetic inhibitors by structure-based drug design. In this report, we reveal two crystal structures of SARS 3CL(pro) complexed with two new inhibitors based on our previous work. These structures combined with six crystal structures complexed with a series of related ligands reported by us are collectively analyzed. To these eight complexes, the structural basis for inhibitor binding was analyzed by the COMBINE method, which is a chemometrical analysis optimized for the protein-ligand complex. The analysis revealed that the first two latent variables gave a cumulative contribution ratio of r(2) = 0.971. Interestingly, scores using the second latent variables for each complex were strongly correlated with root mean square deviations (RMSDs) of side-chain heavy atoms of Met(49) from those of the intact crystal structure of SARS-3CL(pro) (r = 0.77) enlarging the S2 pocket. The substantial contribution of this side chain (∼10%) for the explanation of pIC50 s was dependent on stereochemistry and the chemical structure of the ligand adapted to the S2 pocket of the protease. Thus, starting from a substrate mimic inhibitor, a design for a central scaffold for a low molecular weight inhibitor was evaluated to develop a further potent inhibitor. © 2015 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 391-403, 2016.


Asunto(s)
Cisteína Endopeptidasas , Peptidomiméticos/química , Inhibidores de Proteasas/química , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo/enzimología , Proteínas Virales , Proteasas 3C de Coronavirus , Cristalografía por Rayos X , Cisteína Endopeptidasas/química , Proteínas Virales/antagonistas & inhibidores , Proteínas Virales/química
19.
Virology ; 486: 63-70, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26402376

RESUMEN

The prion strain-specific mechanism by which normal prion protein is converted to abnormal prion protein remains largely unknown. This study found that insect juvenile hormone III reduced abnormal prion protein levels only in cells infected with the RML prion. We conducted a structure-activity analysis using juvenile hormone III biosynthetic intermediates in the isoprenoid pathway. Both farnesol and geranylgeraniol, the most potent inhibitors of abnormal prion protein formation, behaved in an RML prion-dependent fashion. Neither of them modified cellular and cell surface prion protein levels. Events downstream of this pathway include cholesterol biosynthesis and protein prenylation. However, neither of these isoprenoid compounds modified lipid raft microdomains and cellular cholesterol levels and neither affected the representative prenylated protein expression levels of prenylation pathways. Therefore, these isoprenoid compounds are a new class of prion strain-dependent antiprion compounds. They are useful for exploring strain-specific prion biology.


Asunto(s)
Priones/antagonistas & inhibidores , Terpenos/química , Terpenos/farmacología , Animales , Línea Celular Tumoral , Ratones , Estructura Molecular , Priones/genética , Priones/metabolismo , Prenilación de Proteína/efectos de los fármacos , Relación Estructura-Actividad
20.
Bioorg Med Chem ; 23(17): 5626-40, 2015 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-26264846

RESUMEN

A superior substrate sequence for BACE1 containing transition-state mimics at the scissile site was evaluated as a protease inhibitor. Hydroxymethylcarbonyl (HMC) and hydroxyethylamine (HEA) isosteres were selected as the transition state mimics, and incorporated into the scissile site of the superior sequence covering the P4 to P1' sites (Glu-Ile-Thi-Thi(*)Nva; (*)denotes the cleavage site). Isosteres having different absolute configurations of the hydroxyl group were synthesized separately, and the effect of the configuration was evaluated. Configuration of the hydroxyl group of each isostere showed a marked effect on the inhibitory activity; anti-configuration to the scissile site substituent had potent inhibitory activity in an HMC-type inhibitor, whereas anti-configuration of HEA-type inhibitors showed no inhibitory activity. Structural evaluations based on X-ray crystallographic analyses of recombinant BACE1 in complex with each inhibitor provided insights into the protein-ligand interactions, especially at the prime sites.


Asunto(s)
Enfermedad de Alzheimer/genética , Secretasas de la Proteína Precursora del Amiloide/genética , Secretasas de la Proteína Precursora del Amiloide/metabolismo , Ácido Aspártico Endopeptidasas/genética , Ácido Aspártico Endopeptidasas/metabolismo , Péptidos/química , Sitios de Unión , Modelos Moleculares
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