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1.
Eur J Med Chem ; 186: 111864, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31767136

RESUMO

A series of indazolyl-substituted piperidin-4-yl-aminopyrimidines (IPAPYs) were designed from two potent HIV-1 NNRTIs piperidin-4-yl-aminopyrimidine 3c and diaryl ether 4 as the lead compounds by molecular hybridization strategy. The target molecules 5a-q were synthesized and evaluated for their anti-HIV activities and cytotoxicities in MT-4 cells. 5a-q displayed moderate to excellent activities against wild-type (WT) HIV-1 with EC50 values ranging from 1.5 to 0.0064 µM. Among them, 5q was regarded as the most excellent compound against WT HIV-1 (EC50 = 6.4 nM, SI = 2500). And also, it displayed potent activities against K103 N (EC50 = 0.077 µM), Y181C (EC50 = 0.11 µM), E138K (EC50 = 0.057 µM), and moderate activity against double mutants RES056 (EC50 = 8.7 µM). Moreover, the structure-activity relationships (SARs) were summarized, and the molecular docking was performed to investigate the binding mode of IPAPYs and HIV-1 reverse transcriptase.


Assuntos
Fármacos Anti-HIV/farmacologia , Desenho de Drogas , Transcriptase Reversa do HIV/antagonistas & inibidores , HIV/efeitos dos fármacos , Indazóis/farmacologia , Piperidinas/farmacologia , Pirimidinas/farmacologia , Inibidores da Transcriptase Reversa/farmacologia , Fármacos Anti-HIV/síntese química , Fármacos Anti-HIV/química , Relação Dose-Resposta a Droga , Transcriptase Reversa do HIV/metabolismo , Humanos , Indazóis/química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Piperidinas/síntese química , Piperidinas/química , Pirimidinas/síntese química , Pirimidinas/química , Inibidores da Transcriptase Reversa/síntese química , Inibidores da Transcriptase Reversa/química , Relação Estrutura-Atividade
2.
Sci Prog ; : 36850419875662, 2019 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-31829861

RESUMO

To improve the dynamic response performance of a high-flow electro-hydraulic servo system, scholars have conducted considerable research on the synchronous and time-sharing controls of multiple valves. However, most scholars have used offline optimization to improve control performance. Thus, control performance cannot be dynamically adjusted or optimized. To repeatedly optimize the performance of multiple valves online, this study proposes a method for connecting a high-flow proportional valve in parallel with a low-flow servo valve. Moreover, this study proposes an algorithm in which a proportional-integral-derivative system and multivariable predictive control system are used as an inner loop and outer loop, respectively. The simulation and experimental results revealed that dual-valve parallel control could effectively improve the control accuracy and dynamic response performance of an electro-hydraulic servo system and that the proportional-integral-derivative-multivariable predictive control controller could further dynamically improve the control accuracy.

3.
Huan Jing Ke Xue ; 40(12): 5191-5201, 2019 Dec 08.
Artigo em Chinês | MEDLINE | ID: mdl-31854589

RESUMO

This paper discusses the concentration characteristics of PM2.5, as well as its relationship with meteorological factors in autumn and winter (from September to the following February), from 2013 to 2018 in the Beijing-Tianjin-Hebei (BTH) region. The accuracy and uncertainty of the air quality forecast models NAQPMS(nested air quality prediction modeling system), CMAQ(community multiscale air quality modeling system), and CAMx (comprehensive air quality model with extensions) were analyzed based on the model-predicted and measured PM2.5 concentration in autumn and winter from 2015 to 2018. The accuracy of NAQPMS, CMAQ, and CAMx during typical heavy air pollution was also tested. Moreover, methods to improve the accuracy of the model forecast were discussed. The results showed that the mean concentrations of PM2.5 in the BTH region were 122, 98, 82, 99, and 65 µg·m-3 in the five autumn and winter periods, respectively. When the air quality index (AQI) exceeded 150 during each autumn and winter, it reached 229, 198, 210, 204, and 180 µg·m-3, respectively. There were 64 occurrences of heavy regional PM2.5 air pollution in autumn and winter from 2013 to 2018. The average duration was longest in the 2013 to 2014 period, and shortest in the 2017 to 2018 period. The peak concentration and average concentration of PM2.5 decreased year on year, except for the period from 2016 to 2017. In autumn and winter, PM2.5 concentration had a relatively close relationship with relative humidity, wind and sunshine duration, compared with a weak relationship with temperature and air pressure. Regional heavy air pollution always happened under the condition of low wind speed(less than 2 m·s-1),higher relative humidity(greater than 65%),and southwest and northeast wind direction. In addition, the heavy air pollution of PM2.5 in BTH in autumn and winter can be effectively forecasted by NAQPMS, CMAQ, and CAMx. The predicted and measured PM2.5 concentration showed a close relationship. The models performed well in forecasting Zhangjiakou, Chengde, and Qinhuangdao, but by contrast overestimated in Tangshan, Shijiazhuang, Baoding, Beijing, and Tianjin. The uncertainty of emission sources, measured and predicted meteorological data, and the atmospheric chemical reaction mechanism may be the main reasons for the overestimate.

4.
Eur J Pharmacol ; 864: 172717, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31586637

RESUMO

Homocysteine (Hcy) is an independent risk factor in the development of cardiovascular diseases (CVD). Hyperhomocysteinemia (HHcy), induces the injury of vascular endothelial cells via oxidative stress. Oxymatrine (OMT), one of the main components of Sophora flavescens, has displayed anti-inflammatory, anti-oxidant and anti-apoptotic activity. However, the effect of OMT on the Hcy-induced endothelial injury is not clearly defined yet. The aim of this study was to determine the protective effect of OMT on the Hcy-induced endothelial injury and its mechanisms involved. Human umbilical vein endothelial cells (HUVECs) were cultured in vitro. Methyl thiazolyl tetrazolium assay (MTT), fluorescence staining, flow cytometry and western blotting were used in this study. OMT prevented the Hcy-induced toxicity and apoptosis in HUVECs. Moreover, OMT suppressed Hcy-induced increases in reactive oxygen species, lactate dehydrogenase, malondialdehyde levels and increased superoxide dismutase levels. OMT reversed the Hcy-induced decrease in the protein expression of nuclear factor erythroid-2-related factor 2 (Nrf2). In addition, OMT reversed the Hcy-induced apoptosis related biochemical changes such as decreased mitochondrial membrane potential and Bcl-2/Bax protein ratio, and increased protein expression of caspase-9 and caspase-3. Furthermore, OMT elevated the phosphorylation levels of Akt and eNOS, and the formation of nitric oxide (NO) in injured cells. These results suggest that OMT prevents Hcy-induced endothelial injury by regulating mitochondrial-dependent apoptosis and Akt-eNOS-NO signaling pathways concomitantly with accentuation of Nrf2 expression.

5.
J Orthop Sci ; 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31607516

RESUMO

BACKGROUND: The use of 3D-printed scaffolds in repairing bone defects remains unexplored. We aimed to determine whether the duration of electrochemical deposition (ECD) affects the properties of hydroxyapatite (HA) coatings on 3D-printed titanium (TI) scaffolds as well as the corresponding phenotype of MC3T3-E1 cells seeded on these surfaces. METHODS: Five groups of HA-coated TI scaffolds were produced using different durations of ECD (0, 5, 10, 20, and 30 min) and examined under scanning electron microscopy (SEM). MC3T3-E1 cell adhesion to the HA-coated scaffolds and subsequent proliferation and viability were assessed using SEM, DAPI staining, EdU staining, and Alamar Blue assay, respectively. MC3T3-E1 cell expression of osteogenic genes was analyzed by fluorescence RT-PCR. RESULTS: On SEM, longer ECD durations resulted in more compact HA crystals of differing morphology coated onto the TI scaffolds. MC3T3-E1 cell adhesion differed among the five groups (p < 0.05), with the largest number of cells adhered to the scaffolds prepared with 30 min of ECD, followed by the group prepared with 20 min of ECD. However, the ECD duration of 20 min was associated with the highest cell viability and proliferation rate (both p < 0.05) as well as the highest mRNA expression levels of alkaline phosphatase, collagen I, osteocalcin and runt-related transcription factor 2 among the five groups (p < 0.05). CONCLUSIONS: In the fabrication of HA-coated 3D printed TI scaffolds, an ECD duration of 20 min resulted in scaffolds that best promoted MC3T3-E1 cell viability, proliferation and osteogenic gene expression.

6.
Eur J Neurosci ; 2019 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-31491043

RESUMO

The role of the fibroblast growth factor (FGF) system in depression has received considerable attention in recent years. To understand the role of this system, it is important to identify the specific members of the FGF family that have been implicated and the various mechanisms that they modulated. Here, we review the role of FGFs in depression and integrate evidence from clinical and basic research. These data suggest that changes in the FGF family are involved in depression and possibly in a wider range of psychiatric disorders. We analyse the abnormalities of FGF family members in depression and their roles in modulating depression-related molecules. The role of the FGF family in depression and related disorders needs to be studied in more detail.

7.
Eur J Med Chem ; 174: 277-291, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31051402

RESUMO

Since the entrance channel was proposed as a new binding site in non-nucleoside reverse transcriptase inhibitor binding pocket (NNIBP) of HIV-1 reverse transcriptase (RT) in 2012, a huge number of HIV-1 inhibitors acting on this target have sprung up, aiming to discover promising inhibitors with excellent antiviral activities, physicochemical properties, and so on. From 2012 to 2018, many noteworthy compounds have been continuously discovered. In this review, the recent progress in HIV-1 inhibitors targeting the entrance channel of HIV-1 NNIBP was summarized and reviewed, which would provide useful clues and inspiration for further design of HIV-1 inhibitors.


Assuntos
Fármacos Anti-HIV/farmacologia , Transcriptase Reversa do HIV/antagonistas & inibidores , HIV-1/efeitos dos fármacos , Compostos Heterocíclicos/farmacologia , Inibidores da Transcriptase Reversa/farmacologia , Animais , Fármacos Anti-HIV/química , Sítios de Ligação , Linhagem Celular Tumoral , Transcriptase Reversa do HIV/química , Compostos Heterocíclicos/química , Humanos , Simulação de Acoplamento Molecular , Inibidores da Transcriptase Reversa/química
8.
Dalton Trans ; 48(19): 6323-6327, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-30990479

RESUMO

Spin crossover and structural phase transition in three pairs of homochiral and heterochiral [Fe(pybox)2]2+ diastereomers were investigated through magnetic and crystallographic studies. Herein, we show that the spin transition properties of these compounds are strongly related to the homochiral or heterochiral assembly of the ligands and structural phase transition. Our work demonstrates that chirality is a feasible factor to modulate and influence the molecular geometry and thus the spin-crossover properties of complexes.

9.
Chemistry ; 25(33): 7866-7873, 2019 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-30893491

RESUMO

A fluorophilic fluorescent probe based on a perfluoroalkyl-substituted bis(binaphthyl) compound was designed and synthesized. It displayed a highly enantioselective fluorescence response toward structurally diverse amino acids in a biphasic fluorous/aqueous system with enantiomeric fluorescent enhancement ratio (ef; ΔID /ΔIL ) values up to 45.2 (histidine). It can be used to determine the enantiomeric compositions of amino acids and also allows the amino acid enantiomers to be visually discriminated. NMR and mass-spectroscopic investigations provided insights into the observed high enantioselectivity. This biphasic fluorescent recognition was used to determine the enantiomeric composition of the crude phenylalanine products generated by an enzyme-catalyzed asymmetric hydrolysis under various reaction conditions. The fluorous-phase-based fluorescence measurement under the biphasic conditions was able to minimize the interference of other reaction components and thus has potential in asymmetric reaction screening.

10.
J Am Chem Soc ; 141(1): 175-181, 2019 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-30525565

RESUMO

A novel fluorescent probe based on a bisbinaphthyl structure has been designed and synthesized. This compound in combination with Zn(II) has exhibited highly enantioselective fluorescence enhancement with 13 common free amino acids. For example, its enantiomeric fluorescent enhancement ratios ( ef or Δ IL/Δ ID) in the presence of the following amino acids are extremely high: 177 for valine, 199 for methionine, 186 for phenylalanine, 118 for leucine, and 89 for alanine. The observed high enantioselectivity and the extent of the substrate scope are unprecedented in the fluorescent recognition of free amino acids. This fluorescent probe can be applied to determine the enantiomeric composition of the structurally diverse chiral amino acids. NMR and mass spectroscopic investigations have provided clues to elucidate the observed high enantioselectivity.

11.
Eur J Med Chem ; 158: 371-392, 2018 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-30223123

RESUMO

HIV-1 nonnucleoside reverse transcriptase inhibitors (NNRTIs) have been playing an important role in the fight against acquired immunodeficiency syndrome (AIDS). Diarylpyrimidines (DAPYs) as the second generation NNRTIs, represented by etravirine (TMC125) and rilpivirine (TMC278), have attracted extensive attention due to their extraordinary potency, high specificity and low toxicity. However, the rapid emergence of drug-resistant virus strains and dissatisfactory pharmacokinetics of DAPYs present new challenges. In the past two decades, an increasing number of novel DAPY derivatives have emerged, which significantly enriched the structure-activity relationship of DAPYs. Studies of crystallography and molecular modeling have afforded a lot of useful information on structural requirements of NNRTIs, which contributes greatly to the improvement of their resistance profiles. In this review, we reviewed the discovery history and their evolution of DAPYs including their structural modification, derivatization and scaffold hopping in continuous pursuit of excellent anti-HIV drugs. And also, we discussed the prospect of DAPYs and the directions of future efforts.


Assuntos
Transcriptase Reversa do HIV/antagonistas & inibidores , HIV-1/enzimologia , Pirimidinas/química , Pirimidinas/farmacologia , Inibidores da Transcriptase Reversa/química , Inibidores da Transcriptase Reversa/farmacologia , Fármacos Anti-HIV/química , Fármacos Anti-HIV/farmacologia , Infecções por HIV/tratamento farmacológico , Infecções por HIV/virologia , Transcriptase Reversa do HIV/metabolismo , HIV-1/efeitos dos fármacos , Humanos , Simulação de Acoplamento Molecular , Relação Estrutura-Atividade
12.
J Am Chem Soc ; 140(39): 12369-12373, 2018 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-30220196

RESUMO

Metal-organic layers (MOLs), a free-standing monolayer version of two-dimensional metal-organic frameworks (MOFs), have emerged as a new class of 2D materials for many potential applications. Here we report the design of a new photosensitizing MOL, Hf12-Ru, based on Hf12 secondary building units (SBUs) and [Ru(bpy)3]2+ (bpy = 2,2'-bipyridine) derived dicarboxylate ligands. After modifying the SBU surface of Hf12-Ru with M(bpy)(CO)3X (M = Re and X = Cl or M = Mn and X = Br) derived capping molecules through carboxylate exchange reactions, the resultant Hf12-Ru-Re and Hf12-Ru-Mn MOLs possess both [Ru(bpy)3]2+ photosensitizers and M(bpy)(CO)3X catalysts for efficient photocatalytic CO2 reduction. The proximity of the MOL skeleton to the capping ligands (1-2 nm) facilitates electron transfer from the reduced photosensitizer [Ru(bpy)3]+ to MI(bpy)(CO)3X (M = Re, Mn) catalytic centers, resulting in CO2 reduction turnover numbers of 8613 under artificial visible light and of 670 under sunlight. MOLs thus represent a novel platform to assemble multifunctional materials for studying artificial photosynthesis.

13.
Angew Chem Int Ed Engl ; 57(43): 14090-14094, 2018 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-30129281

RESUMO

Metal-organic frameworks (MOFs) have been extensively used for single-site catalysis and light harvesting, but their application in multicomponent photocatalysis is unexplored. We report here the successful incorporation of an IrIII photoredox catalyst and a NiII cross-coupling catalyst into a stable Zr12 MOF, Zr12 -Ir-Ni, to efficiently catalyze C-S bond formation between various aryl iodides and thiols. The proximity of the IrIII and NiII catalytic components to each other (ca. 0.6 nm) in Zr12 -Ir-Ni greatly facilitates electron and thiol radical transfers from Ir to Ni centers to reach a turnover number of 38 500, an order of magnitude higher than that of its homogeneous counterpart. This work highlights the opportunity in merging photoredox and organometallic catalysts in MOFs to effect challenging organic transformations.

14.
Cell Death Dis ; 9(7): 774, 2018 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-29991678

RESUMO

Downregulation of suppressor of cytokine signalling-1 (SOCS1) is one of the vital reasons for JAK1-STAT3 pathway activation in acute myeloid leukaemia (AML). CUE domain-containing 2 (CUEDC2) was a novel interacting partner of SOCS1 and a positive correlation between the expression of CUEDC2 and SOCS1 was confirmed in primary AML cells and AML cell lines without SOCS1 promoter methylation. We aimed to explore roles of CUEDC2 in regulating ubiquitin-mediated degradation of SOCS1 in the leukaemogenesis of AML.According to in vitro experiments, CUEDC2 overexpression increased the level of SOCS1 protein, suppressed JAK1-STAT3 pathway activation. The suppression of this pathway inhibited AML cells' proliferation by causing G1 arrest and enhanced AML cells' sensitivity to cytarabine and idarubicin. Similarity, downregulation of CUEDC2 produced opposite results. Knockout or low expression of CUEDC2 in mouse or AML patients displayed lower overall survival and event-free survival rates, compared with these mouse and AML patients had high-CUEDC2 expression. Mechanistic studies revealed that CUEDC2 overexpression attenuated SOCS1 ubiquitination, facilitated its stabilisation by enhancing SOCS1, Elongin C and Cullin-2 (CUL2) interactions, thus inhibited JAK1-STAT3 pathway and leukaemogenesis of AML. Therefore, our novel findings indicated that CUEDC2 interacted with SOCS1 to suppress SOCS1's ubiquitin-mediated degradation, JAK1-STAT3 pathway activation and leukaemogenesis of AML.


Assuntos
Proteínas de Transporte/metabolismo , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/patologia , Proteínas de Membrana/metabolismo , Proteína 1 Supressora da Sinalização de Citocina/metabolismo , Animais , Apoptose/genética , Apoptose/fisiologia , Proteínas de Transporte/genética , Ciclo Celular/genética , Ciclo Celular/fisiologia , Linhagem Celular , Proliferação de Células/genética , Proliferação de Células/fisiologia , Sobrevivência Celular/genética , Sobrevivência Celular/fisiologia , Células HL-60 , Humanos , Imunoprecipitação , Células K562 , Leucemia Mieloide Aguda/genética , Proteínas de Membrana/genética , Camundongos , Ligação Proteica , Proteína 1 Supressora da Sinalização de Citocina/genética , Células U937
15.
Int J Biol Macromol ; 116: 1064-1073, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29782975

RESUMO

Janus tyrosine kinase 2 (JAK2) mediates downstream signaling of cytokine receptors in all hematological lineages, constitutively active somatic JAK2 mutations play key roles in the pathology of myeloproliferative neoplasms (MPNs). Recently, germline JAK2 mutations are also associated with triple-negative MPNs. A novel germline mutation JAK2 V625F is reported to be involved in a subset of MPNs patients. However, the pathogenesis of this mutation caused MPN is still unclear. In this study, the homology models of JAK2 V625F showed that the newly formed interaction between F625 and Y613 disrupted the JAK2 JH1-JH2 domain interactions was responsible for its activation, when F625 and Y613 interaction was disrupted, its activity significantly decreased. While, when this interaction was repaired whether by forming hydrogen bond or salt bond, it would cause JAK2 activation. Biochemical studies also demonstrated that JAK2 V625F mutation led to JAK2-STAT5 pathway activation and promoted the proliferation of BaF3 cells. Thus, our results herein provide clues to understand the mechanism JAK2 V625F mutation caused MPNs and give information for the development of JAK2 mutation specific inhibitors.


Assuntos
Mutação em Linhagem Germinativa , Neoplasias Hematológicas , Janus Quinase 2 , Mutação de Sentido Incorreto , Transtornos Mieloproliferativos , Proteínas de Neoplasias , Transdução de Sinais , Substituição de Aminoácidos , Linhagem Celular Tumoral , Neoplasias Hematológicas/enzimologia , Neoplasias Hematológicas/genética , Neoplasias Hematológicas/patologia , Humanos , Ligações de Hidrogênio , Janus Quinase 2/química , Janus Quinase 2/genética , Janus Quinase 2/metabolismo , Transtornos Mieloproliferativos/enzimologia , Transtornos Mieloproliferativos/genética , Transtornos Mieloproliferativos/patologia , Proteínas de Neoplasias/química , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Fator de Transcrição STAT5/genética , Fator de Transcrição STAT5/metabolismo
16.
Int J Biol Macromol ; 117: 271-279, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-29842959

RESUMO

Although roles of somatic JAK2 mutations in clonally myeloproliferative neoplasms (MPNs) are well established, roles of germline JAK2 mutations in the pathogenesis of MPNs remain unclear. Recently, a novel activating, germline JAK2 F556V mutation was identified and involved in the pathogenesis of MPNs, but, its pathogenesis mechanism was still unknown. In this study, homology models of JAK2 demonstrated that F556 located between two threonine residues which interacted with ATP phosphate groups by hydrogen bonds, Thr555 with the γ-phosphate and Thr557 with the ß-phosphate in the active site of JAK2's JH2 domain. Moreover, the hydrogen bond between Thr557 and Arg715 played vital roles in sustaining the structural conformation of JH2's active site and JH1-JH2 domains' interactions. When F556 was replaced by other amino acids except Trp, the hydrogen bond, JH2 domain's structural conformation and JH1-JH2 domains' interactions disrupted for changing the helix between ß2 and ß3 strands which finally caused JAK2 activation. Mechanistic and functional studies showed that JAK2 F556V mutation disrupted JAK2 JH2 domain's activity, caused JAK2-STAT5 pathway activation and promoted the proliferation of BaF3 cells. Thus, our results herein may provide clues to understand the pathogenesis mechanism of JAK2 F556V mutation in the MPNs.


Assuntos
Transformação Celular Neoplásica , Janus Quinase 2/química , Janus Quinase 2/genética , Mutação , Domínio Catalítico , Proliferação de Células , Estabilidade Enzimática , Humanos , Simulação de Dinâmica Molecular , Fosforilação , Redobramento de Proteína
17.
J Am Chem Soc ; 140(16): 5326-5329, 2018 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-29578703

RESUMO

We report the design of two new metal-organic frameworks (MOFs), Ru-TBP and Ru-TBP-Zn, based on Ru2 secondary building units (SBUs) and porphyrin-derived tetracarboxylate ligands. The proximity of Ru2 SBUs to porphyrin ligands (∼1.1 nm) facilitates multielectron transfer from excited porphyrins to Ru2 SBUs to enable efficient visible-light-driven hydrogen evolution reaction (HER) in neutral water. Photophysical and electrochemical studies revealed oxidative quenching of excited porphyrin by Ru2 SBUs as the initial step of the HER process and the energetics of key intermediates in the catalytic cycle. Our work provides a new strategy to building multifunctional MOFs with synergistic ligands and SBUs for efficient photocatalysis.

18.
Int J Biol Macromol ; 111: 247-254, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29325742

RESUMO

Arginine kinase (AK) catalyzes the reversible phosphorylation of arginine by ATP, yielding the phosphoarginine. Amino acid residues in the guanidine specificity (GS) region play important roles in the guanidine-recognition. However, little is known about roles of amino acid residue G66 in the GS region in proteins folding, activity and structural stability. In this study, a series of G66 mutations were constructed to investigate its roles in AK's structural stability and activity. Our studies revealed that mutations in this conserved site could cause pronounced loss of activity, conformational changes and structural stability. Spectroscopic experiments indicate that G66 mutations influences AK transition from the molten globule intermediate to the native state in folding process. These results provided herein may suggest that amino acid residue G66 may play a relatively important role in AK's activity and structural stability.


Assuntos
Aminoácidos/genética , Arginina Quinase/química , Gafanhotos/enzimologia , Guanidina/química , Aminoácidos/química , Animais , Arginina Quinase/genética , Estabilidade Enzimática , Gafanhotos/química , Cinética , Mutação , Desnaturação Proteica , Dobramento de Proteína , Estrutura Terciária de Proteína
19.
Int J Biol Macromol ; 107(Pt A): 512-520, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28916380

RESUMO

Creatine kinase (CK) is a key enzyme for cellular energy metabolism, catalyzing the reversible phosphoryl transfer from phosphocreatine to ADP in vertebrates. CK contains a pair of highly conserved amino acids (H66 and D326) which might play an important role in sustaining the compact structure of CK by linking its N- and C- terminal domains; however the mechanism is still unclear. In this study, spectroscopic, structural modeling and protein folding experiments suggested that D326A, H66P and H66P/D326A mutations led to disruption of the hydrogen bond between those two amino acid residues and form the partially unfolded state which made it easier to be inactivated and unfolded under environmental stresses, and more prone to form insoluble aggregates. The formation of insoluble aggregates would decrease levels of active CKs which may provide clues in CK deficiency disease. Moreover, these results indicated that the degree of synergism had closely relationship to the conformational changes of CK. Thus, our results provided clues for understanding the mechanism of amino acid residues outside the active site in regulating substrate synergism.


Assuntos
Aminoácidos/química , Creatina Quinase/química , Metabolismo Energético/genética , Conformação Proteica , Aminoácidos/genética , Domínio Catalítico , Sequência Conservada/genética , Creatina Quinase/genética , Humanos , Cinética , Mutação , Agregados Proteicos/genética , Domínios Proteicos , Dobramento de Proteína , Especificidade por Substrato
20.
Viral Immunol ; 31(1): 34-39, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-28514189

RESUMO

The attenuated C-strain vaccine against classical swine fever virus (CSFV) is one of the safest and most effective attenuated vaccines. However, little is known of the host immune response after vaccination with the C-strain vaccine. Blood samples from vaccinated pigs were collected to evaluate the number of immune cells, the level of specific CSFV antibody, and related cytokines induced by the vaccination of C-strain vaccine. The C-strain nucleic acid was gradually removed and specific antibody to vaccine kept increasing; the amount of the lymphocyte, Tc cell, and Th cell increased; some inflammatory cytokines such as interleukin (IL)-1 and tumor necrosis factor-α mainly showed downregulated trends, but IL-6 and IL-8 were upregulated greatly; IL-2, IL-4, IL-5, IL-12p40, IL-13, interferon (IFN)-I, and Toll-like receptors (TLRs) kept high expression level after 28 days postvaccination (dpv); IFN-γ was upregulated slightly at 5 and 9 dpv, respectively. These results suggest that the C-strain vaccine induces a Th2 cell response to produce the specific antibody. The vaccine virus replicates at very low level. C-strain vaccine burden has close relationship with the expression of TLRs. The overexpression of TLRs initiates the innate immune system to clear up the vaccine. Meanwhile, ILs expressed by immune system induce the differentiation of B cells and produce specific antibody.


Assuntos
Vírus da Febre Suína Clássica/imunologia , Peste Suína Clássica/prevenção & controle , Citocinas/genética , Suínos/imunologia , Subpopulações de Linfócitos T/imunologia , Vacinação/veterinária , Vacinas Virais/imunologia , Animais , Anticorpos Antivirais/sangue , Peste Suína Clássica/sangue , Peste Suína Clássica/imunologia , Regulação da Expressão Gênica , Cinética , Contagem de Linfócitos , Masculino , RNA Viral/análise , Suínos/virologia , Linfócitos T Citotóxicos/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Receptores Toll-Like/genética , Vacinas Atenuadas/administração & dosagem , Vacinas Atenuadas/imunologia , Vacinas Virais/administração & dosagem
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