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1.
Int Arch Allergy Immunol ; : 1-12, 2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38797160

RESUMO

INTRODUCTION: Kamebakaurin is an active constituent of both Rabdosia japonica and Rabdosia excisa, which are utilized in Chinese traditional medicine for improving symptoms in patients with allergies. We investigated the molecular mechanisms of the anti-allergic effects of kamebakaurin using BMMCs. METHODS: The degranulation ratio, histamine release, and the interleukin (IL)-4, leukotriene B4 (LTB4), and cysteinyl leukotriene productions on antigen-triggered BMMC were investigated. Additionally, the effects of kamebakaurin on signal transduction proteins were examined by Western blot and binding to the Syk and Lyn kinase domain was calculated. The effects of kamebakaurin on antigen-induced hyperpermeability were investigated using mouse model. RESULTS: At 10 µm, kamebakaurin partially inhibited degranulation, histamine release, and IL-4 production. At 30 µm, kamebakaurin partially reduced LTB4 and cysteinyl leukotriene productions and suppressed degranulation, histamine release, and IL-4 production. Phosphorylation of both Syk Y519/520 and its downstream protein, Gab2, was reduced by kamebakaurin, and complete inhibition was observed with 30 µm kamebakaurin. In contrast, phosphorylation of Erk was only partially inhibited, even in the presence of 30 µm kamebakaurin. Syk Y519/520 is known to be auto-phosphorylated via intramolecular ATP present in its own ATP-binding site, and this auto-phosphorylation triggers degranulation, histamine release, and IL-4 production. Docking simulation study indicated kamebakaurin blocked ATP binding to the ATP-binding site in Syk. Therefore, inhibition of Syk auto-phosphorylation by kamebakaurin binding to the Syk ATP-binding site appeared to cause a reduction of histamine release and IL-4 production. Kamebakaurin inhibited antigen-induced vascular hyperpermeability in a dose-dependent fashion but did not reduce histamine-induced vascular hyperpermeability. CONCLUSION: Kamebakaurin ameliorates allergic symptoms via inhibition of Syk phosphorylation; thus, kamebakaurin could be a lead compound for the new anti-allergic drug.

2.
Chem Pharm Bull (Tokyo) ; 71(7): 545-551, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37394603

RESUMO

We designed and synthesized a chiral ligand N-(anthracen-9-ylmethyl)-1-(pyridin-2-yl)-N-(pyridin-2-ylmethyl)ethanamine (APPE) DNA photocleavage agent to investigate the effects of chirality of bis(2-picolyl)amine on the DNA photocleavage activity of metal complexes. The structures of ZnII and CoII complexes in APPE were analyzed via X-ray crystallography and fluorometric titration. APPE formed metal complexes with a 1 : 1 stoichiometry in both the crystalline and solution states. Fluorometric titration was used to show that the ZnII and CoII association constants of these complexes (log Kas) were 4.95 and 5.39, respectively. The synthesized complexes were found to cleave pUC19 plasmid DNA when irradiated at 370 nm. The DNA photocleavage activity of the ZnII complex was higher than that of the CoII complex. The absolute configuration of the methyl-attached carbon did not affect DNA cleavage activity and, unfortunately, an achiral APPE derivative without the methyl group (ABPM) was found to perform DNA photocleavage more effectively than APPE. One reason for this may be that the methyl group suppressed the structural flexibility of the photosensitizer. These results will be useful for the design of new photoreactive reagents.


Assuntos
Complexos de Coordenação , Zinco , Zinco/química , Cobalto/química , Complexos de Coordenação/farmacologia , Complexos de Coordenação/química , Cobre/química , Aminas/química , DNA/química , Cristalografia por Raios X , Ligantes
3.
Int Arch Allergy Immunol ; 183(10): 1050-1055, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35810745

RESUMO

BACKGROUND: Mast cells play a central role in allergic responses such as food allergy, asthma, allergic rhinitis, and allergic conjunctivitis. Symptoms in the early phase of these allergic diseases are primarily caused by histamine. However, due to the high histidine content in the cytosol and low histamine content in secretory granules, separating and quantifying histamine from histidine is often difficult. OBJECTIVES: We studied a method for rapid and sensitive quantitation of mast cell-derived histamine and evaluated its application to allergic disease research. METHODS: Bone marrow-derived mouse mast cells (BMMCs) were employed in this study. IgE-sensitized BMMCs were activated by FcεRI cross-linking. After activation, both the histamine released to the supernatant and histamine remaining in BMMCs were didansylated and then analyzed by high-performance liquid chromatography with fluorescence detection (HPLC-FD). Didansyl histamine was synthesized as a standard material. RESULTS: Synthetic didansyl histamine was detected by HPLC-FD with a peak retention time of 18.5 min. Very high linearity of the standard curve was maintained at concentrations of 10 pg/µL or less when the didansyl histamine method was used. This method enables detection of histamine released from 1 × 105 BMMCs. In addition, the histamine concentration in the supernatant due to spontaneous release was also determined. Finally, the ratio of histamine release was highly correlated with the degranulation ratio. CONCLUSION: These results indicate that the proposed method using didansylated histamine to determine mast cell-derived histamine is highly useful for allergy research applications.


Assuntos
Hipersensibilidade , Mastócitos , Animais , Degranulação Celular , Histamina , Histidina , Imunoglobulina E , Camundongos , Receptores de IgE
4.
Planta Med ; 88(12): 1069-1077, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35081628

RESUMO

The liverwort Radula perrottetii contains various bibenzyl derivatives which are known to possess various biological activities, such as anti-inflammatory effects. Mast cells (MC) play crucial roles in allergic and inflammatory diseases; thus, inhibition of MC activation is pivotal for the treatment of allergic and inflammatory disorders. We investigated the effects of perrottetin D (perD), isolated from Radula perrottetii, and perD diacetate (Ac-perD) on antigen-induced activation of MCs. Bone marrow-derived MCs (BMMCs) were generated from C57BL/6 mice. The degranulation ratio, histamine release, and the interleukin (IL)-4 and leukotriene B4 productions on antigen-triggered BMMC were investigated. Additionally, the effects of the bibenzyls on binding of IgE to FcεRI were observed by flow cytometry, and signal transduction proteins was examined by Western blot. Furthermore, binding of the bibenzyls to the Fyn kinase domain was calculated. At 10 µM, perD decreased the degranulation ratio (p < 0.01), whereas 10 µM Ac-perD down-regulated IL-4 production (p < 0.05) in addition to decreasing the degranulation ratio (p < 0.01). Both compounds tended to decrease histamine release at a concentration of 10 µM. Although 10 µM perD reduced only Syk phosphorylation, 10 µM Ac-perD diminished phosphorylation of Syk, Gab2, PLC-γ, and p38. PerD appeared to selectively bind Fyn, whereas Ac-perD appeared to act as a weak but broad-spectrum inhibitor of kinases, including Fyn. In conclusion, perD and Ac-perD suppressed the phosphorylation of signal transduction molecules downstream of the FcεRI and consequently inhibited degranulation, and/or IL-4 production. These may be beneficial potential lead compounds for the development of novel anti-allergic and anti-inflammatory drugs.


Assuntos
Antialérgicos , Bibenzilas , Hepatófitas , Animais , Antialérgicos/farmacologia , Bibenzilas/metabolismo , Bibenzilas/farmacologia , Degranulação Celular , Imunoglobulina E , Interleucina-4/metabolismo , Interleucina-4/farmacologia , Leucotrieno B4/metabolismo , Leucotrieno B4/farmacologia , Mastócitos , Camundongos , Camundongos Endogâmicos C57BL , Fosfolipase C gama/metabolismo , Fosfolipase C gama/farmacologia , Receptores de IgE/metabolismo
5.
Bioorg Med Chem Lett ; 35: 127782, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33422608

RESUMO

It is necessary to design a ligand that is compatible with the target molecule to optimally use the DNA-cleaving ability of metal complexes. In this study, we synthesized an optically active dinuclear ligand, (1R,1'R,2R,2'R)-N1,N1'-(anthracene-1,8-diylbis(methylene))bis(N2,N2-bis(pyridin-2-ylmethyl)cyclohexane-1,2-diamine) (R-ABDC, 4a) and its enantiomer (S-ABDC, 4b). We then prepared their Fe(II) complexes by mixing the ligand with FeSO4·7H2O in situ and investigated DNA-cleaving activities using plasmid DNA in the presence of excess sodium ascorbate at atmospheric conditions. The Fe(II) complexes efficiently cleaved DNA and selectively recognized two consecutive A and/or T sequences.


Assuntos
DNA/efeitos dos fármacos , Desenho de Fármacos , Compostos Ferrosos/farmacologia , Clivagem do DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Compostos Ferrosos/síntese química , Compostos Ferrosos/química , Ligantes , Estrutura Molecular , Plasmídeos , Relação Estrutura-Atividade
6.
Bioorg Med Chem Lett ; 36: 127834, 2021 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-33540045

RESUMO

DNA-cleavage agents such as bleomycin have potential anticancer applications. The development of a DNA-cleavage reagent that recognizes specific sequences allows the development of cancer therapy with reduced side effects. In this study, to develop novel compounds with specific DNA-cleavage activities, we synthesized optically active binuclear ligands, (1R,1'R,2R,2'R)-N1,N1'-(meta/para-phenylenebis(methylene))bis(N2,N2-bis(pyridin-2-ylmethyl)cyclohexane-1,2-diamine) and their enantiomers. The DNA-cleavage activities of these compounds were investigated in the presence of Fe(II)SO4 and sodium ascorbate. The obtained results indicated that the Fe(II) complexes of those compounds efficiently cleave DNA and that their cleavage was subtle sequence-selective. Therefore, we succeeded in developing compounds that can be used as small-molecule drugs for cancer chemotherapy.


Assuntos
Cicloexilaminas/farmacologia , Compostos Ferrosos/farmacologia , Cicloexilaminas/síntese química , Cicloexilaminas/química , Clivagem do DNA , Relação Dose-Resposta a Droga , Compostos Ferrosos/síntese química , Compostos Ferrosos/química , Ligantes , Estrutura Molecular , Plasmídeos , Estereoisomerismo , Relação Estrutura-Atividade
7.
Bioorg Med Chem Lett ; 30(7): 127002, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32044184

RESUMO

Induction of heat shock protein 70 (HSP70) is known to be effective against various diseases. We are interested in HSP70 induction capability of an antitumor antibiotic bleomycin which produces oxidative stress by iron chelate formation and oxygen activation in a cell. The HSP70 induction activity of bleomycin and its six metal core analogs was examined, and a compound HPH-1Trt of 10 µM was found to induce this protein in a pheochromocytoma cell line and some T cell and monocytic cell lines. Its mechanism is increase of HSP70 mRNA, but higher concentration of this compound showed toxicity. Two new derivatives were then synthesized, and one of them named DHPH-1Trt was shown to have less toxicity and higher HSP70 induction activity. This study would lead to a clue for new HSP70 inducer clinically used in near future.


Assuntos
Proteínas de Choque Térmico HSP70/metabolismo , Histidina/análogos & derivados , Histidina/farmacologia , Piridinas/farmacologia , Animais , Bleomicina/análogos & derivados , Bleomicina/farmacologia , Bleomicina/toxicidade , Linhagem Celular Tumoral , Proteínas de Choque Térmico HSP70/genética , Histidina/toxicidade , Macaca , Piridinas/síntese química , Piridinas/toxicidade , RNA Mensageiro/metabolismo , Ratos
8.
Chem Pharm Bull (Tokyo) ; 68(8): 713-716, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32741911

RESUMO

With the aim of shedding some light on the still scarcely investigated mechanism of transformation of imines in metal complexes, this study describes the investigation of the hydrogen-deuterium (H/D) exchange reaction of a bis[2-(pyridylmethylidene)-1-(2-pyridylmethylamine]iron(II) complex ([Fe(PMAP)2]2+), following our previous work on a low-spin iron(II) complex bearing two molecules of S-2-pyridylmethylidene-1-(2-pyridyl)ethylamine. This complex has been proven to undergo successive transiminations in acetonitrile, yielding a bis[1-(2-pyridyl)ethylidene-2-pyridylmethylamine]iron(II) complex. In the analogous [Fe(PMAP)2]2+ complex, a 1,3-hydrogen rearrangement occurs in a 10% deuterium oxide-acetonitrile-d3 (D2O-CD3CN) solution. The H/D exchange reaction of [Fe(PMAP)2]2+ was examined in the presence of various concentrations of 2,6-dimethylpyridine as a base in a 10% D2O-CD3CN solution at 45 °C, and the reaction mechanism was investigated.


Assuntos
Complexos de Coordenação/química , Compostos Ferrosos/química , Complexos de Coordenação/síntese química , Medição da Troca de Deutério , Etilaminas/química , Espectroscopia de Ressonância Magnética , Conformação Molecular , Teoria Quântica
9.
Artigo em Inglês | MEDLINE | ID: mdl-31405855

RESUMO

The number of cases of infection with carbapenem-resistant Enterobacteriaceae (CRE) has been increasing and has become a major clinical and public health concern. Production of metallo-ß-lactamases (MBLs) is one of the principal carbapenem resistance mechanisms in CRE. Therefore, developing MBL inhibitors is a promising strategy to overcome the problems of carbapenem resistance conferred by MBLs. To date, the development and evaluation of MBL inhibitors have focused on subclass B1 MBLs but not on B3 MBLs. In the present study, we searched for B3 MBL (specifically, SMB-1) inhibitors and found thiosalicylic acid (TSA) to be a potent inhibitor of B3 SMB-1 MBL (50% inhibitory concentration [IC50], 0.95 µM). TSA inhibited the purified SMB-1 to a considerable degree but was not active against Escherichia coli cells producing SMB-1, as the meropenem (MEM) MIC for the SMB-1 producer was only slightly reduced with TSA. We then introduced a primary amine to TSA and synthesized 4-amino-2-sulfanylbenzoic acid (ASB), which substantially reduced the MEM MICs for SMB-1 producers. X-ray crystallographic analyses revealed that ASB binds to the two zinc ions, Ser221, and Thr223 at the active site of SMB-1. These are ubiquitously conserved residues across clinically relevant B3 MBLs. ASB also significantly inhibited other B3 MBLs, including AIM-1, LMB-1, and L1. Therefore, the characterization of ASB provides a starting point for the development of optimum B3 MBL inhibitors.


Assuntos
Antibacterianos/farmacologia , Enterobacteriaceae/enzimologia , Inibidores de beta-Lactamases/farmacologia , beta-Lactamases/metabolismo , Animais , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Cristalografia por Raios X , Enterobacteriaceae/efeitos dos fármacos , Enterobacteriaceae/genética , Masculino , Camundongos , Testes de Sensibilidade Microbiana , Salicilatos/farmacologia , Compostos de Sulfidrila/farmacologia
10.
Int J Clin Oncol ; 23(2): 361-367, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29151227

RESUMO

BACKGROUND: To evaluate the relationship between biochemical recurrence and post-radiation prostate-specific antigen (PSA) kinetics in patients with localized prostate cancer treated by radiotherapy with various durations of androgen deprivation therapy (ADT). METHODS: We reviewed our single-institution, retrospectively maintained data of 144 patients with T1c-T3N0M0 prostate cancer who underwent three-dimensional conformal radiotherapy (3D-CRT) between December 2005 and December 2015 and 113 patients were fulfilled the inclusion criteria. In this cohort, 3D-CRT was delivered with a dose in the range from 70.0 to 72.0 Gy with ADT. All patients received ADT as concurrent regimens. Biochemical recurrence was defined on the basis of the following: "PSA nadir + 2.0 ng/ml or the clinical judgement of attending physicians". Kaplan-Meier, log-rank, and Cox regression analyses were carried out. RESULTS: The median follow-up period was 54.0 months. The median duration of ADT was 17 months (interquartile range, 10-24 months). There was a trend toward statistical significant correlation between post-radiation PSA decline rate of ≥ 90% and PSA recurrence (p = 0.056). The same correlation could be observed in D'Amico high-risk patients (p = 0.036). However, it was not observed between PSA nadir and PSA recurrence (p = 0.40) in univariate analysis. Furthermore, multivariate analysis showed that post-radiation PSA decline rate of ≥ 90% was a significant predictor of biochemical recurrence in patients who received radiotherapy with various durations of ADT (p = 0.044). CONCLUSIONS: Post-radiation PSA decline rate of ≥ 90% was a prognostic factor for biochemical recurrence in localized prostate cancer patients received 3D-CRT with various durations of ADT.


Assuntos
Antígeno Prostático Específico/sangue , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/radioterapia , Radioterapia Conformacional/métodos , Idoso , Antagonistas de Androgênios/uso terapêutico , Estudos de Coortes , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Masculino , Recidiva Local de Neoplasia/sangue , Recidiva Local de Neoplasia/patologia , Neoplasias da Próstata/metabolismo , Estudos Retrospectivos
11.
Artigo em Inglês | MEDLINE | ID: mdl-28739781

RESUMO

The development of effective inhibitors that block extended-spectrum ß-lactamases (ESBLs) and restore the action of ß-lactams represents an effective strategy against ESBL-producing Enterobacteriaceae We evaluated the inhibitory effects of the diazabicyclooctanes avibactam and OP0595 against TLA-3, an ESBL that we identified previously. Avibactam and OP0595 inhibited TLA-3 with apparent inhibitor constants (Kiapp) of 1.71 ± 0.10 and 1.49 ± 0.05 µM, respectively, and could restore susceptibility to cephalosporins in the TLA-3-producing Escherichia coli strain. The value of the second-order acylation rate constant (k2/K, where k2 is the acylation rate constant and K is the equilibrium constant) of avibactam [(3.25 ± 0.03) × 103 M-1 · s-1] was closer to that of class C and D ß-lactamases (k2/K, <104 M-1 · s-1) than that of class A ß-lactamases (k2/K, >104 M-1 · s-1). In addition, we determined the structure of TLA-3 and that of TLA-3 complexed with avibactam or OP0595 at resolutions of 1.6, 1.6, and 2.0 Å, respectively. TLA-3 contains an inverted Ω loop and an extended loop between the ß5 and ß6 strands (insertion after Ser237), which appear only in PER-type class A ß-lactamases. These structures might favor the accommodation of cephalosporins harboring bulky R1 side chains. TLA-3 presented a high catalytic efficiency (kcat/Km ) against cephalosporins, including cephalothin, cefuroxime, and cefotaxime. Avibactam and OP0595 bound covalently to TLA-3 via the Ser70 residue and made contacts with residues Ser130, Thr235, and Ser237, which are conserved in ESBLs. Additionally, the sulfate group of the inhibitors formed polar contacts with amino acid residues in a positively charged pocket of TLA-3. Our findings provide a structural template for designing improved diazabicyclooctane-based inhibitors that are effective against ESBL-producing Enterobacteriaceae.


Assuntos
Compostos Azabicíclicos/farmacologia , Escherichia coli/efeitos dos fármacos , Lactamas/farmacologia , Inibidores de beta-Lactamases/farmacologia , beta-Lactamases/metabolismo , Domínio Catalítico , Cefalosporinas/farmacologia , Cristalografia por Raios X , Escherichia coli/enzimologia , Humanos , Testes de Sensibilidade Microbiana , beta-Lactamases/química
12.
Antimicrob Agents Chemother ; 60(7): 4274-82, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27161644

RESUMO

Metallo-ß-lactamases (MBLs) confer resistance to carbapenems, and their increasing global prevalence is a growing clinical concern. To elucidate the mechanisms by which these enzymes recognize and hydrolyze carbapenems, we solved 1.4 to 1.6 Å crystal structures of SMB-1 (Serratia metallo-ß-lactamase 1), a subclass B3 MBL, bound to hydrolyzed carbapenems (doripenem, meropenem, and imipenem). In these structures, SMB-1 interacts mainly with the carbapenem core structure via elements in the active site, including a zinc ion (Zn-2), Q157[113] (where the position in the SMB-1 sequence is in brackets after the BBL number), S221[175], and T223[177]. There is less contact with the carbapenem R2 side chains, strongly indicating that SMB-1 primarily recognizes the carbapenem core structure. This is the first report describing how a subclass B3 MBL recognizes carbapenems. We also solved the crystal structure of SMB-1 in complex with the approved drugs captopril, an inhibitor of the angiotensin-converting enzyme, and 2-mercaptoethanesulfonate, a chemoprotectant. These drugs are inhibitors of SMB-1 with Ki values of 8.9 and 184 µM, respectively. Like carbapenems, these inhibitors interact with Q157[113] and T223[177] and their thiol groups coordinate the zinc ions in the active site. Taken together, the data indicate that Q157[113], S221[175], T223[177], and the two zinc ions in the active site are key targets in the design of SMB-1 inhibitors with enhanced affinity. The structural data provide a solid foundation for the development of effective inhibitors that would overcome the carbapenem resistance of MBL-producing multidrug-resistant microbes.


Assuntos
Antibacterianos/química , Carbapenêmicos/química , beta-Lactamases/química , Inibidores da Enzima Conversora de Angiotensina/química , Captopril/química , Domínio Catalítico , Cristalografia por Raios X , Doripenem , Imipenem/química , Meropeném , Mesna/química , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Serratia marcescens/enzimologia , Tienamicinas/química , beta-Lactamases/metabolismo
13.
J Phys Ther Sci ; 28(2): 525-9, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27065540

RESUMO

[Purpose] This study aimed to compare the efficacy of radiofrequency diathermy with that of microwave diathermy in combination with intra-articular injection of hyaluronic acid into the knee of patients with osteoarthritis (OA). [Subjects] A total of 17 patients with knee OA were enrolled. The participants were randomly divided into two groups: a radiofrequency diathermy group (RF group, 9 subjects), and a microwave diathermy group (MW group, 8 subjects). [Methods] Subjects received radiofrequency or microwave thermal therapy 3 times at 1-week intervals. Intra-articular injection of hyaluronic acid was administered 10 min before every thermal therapy session. The outcome was evaluated using the Japan Orthopaedic Association (JOA) and the Lequesne Index (LI) at baseline, at weeks 1 (1 week after the first thermal therapy) and 3 (1 week after the last thermal therapy). [Results] The JOA scale increased significantly after three sessions of thermal therapy in the RF group, while no significant increase was observed in the MW group. LI decreased significantly after 3 weeks in the RF group. In the MW group, there was no significant difference in LI between the two time points. [Conclusion] This study revealed that symptom relief in patients with knee OA was greater with radiofrequency diathermy than with microwave diathermy with concurrent use of hyaluronic acid injection, presumably due to the different heating characteristics of the two methods.

14.
Bioorg Med Chem ; 23(17): 5476-82, 2015 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-26260338

RESUMO

Previously we have reported a metal chelating histidine-pyridine-histidine system possessing a trityl group on the histidine imidazole, namely HPH-2Trt, which induces apoptosis in human pancreatic adenocarcinoma AsPC-1 cells. Herein the influence of the imidazole substitution of HPH-2Trt was examined. Five related compounds, HPH-1Trt, HPH-2Bzl, HPH-1Bzl, HPH-2Me, and HPH-1Me were newly synthesized and screened for their activity against AsPC-1 and brain tumor cells U87 and U251. HPH-1Trt and HPH-2Trt were highly active among the tested HPH compounds. In vitro DNA cleavage assay showed both HPH-1Trt and HPH-2Trt completely disintegrate pUC19 DNA. The introduction of trityl group decisively potentiated the activity.


Assuntos
DNA/química , Histidina/química , Imidazóis/química , Piridinas/química , Quelantes/química , Humanos
15.
Bioorg Chem ; 62: 8-14, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26159895

RESUMO

A tetrapeptide, l-histidyl-glycyl-glycyl-l-histidine (HGGH), was synthesized and the pUC19 plasmid DNA cleaving activity by copper(II) complex of HGGH (Cu(II)-HGGH) was investigated. Cu(II)-HGGH showed bleomycin-like DNA cleaving activity and, at 50nM, converted a supercoiled DNA efficiently to a linear DNA in the presence of 500µM H2O2/sodium ascorbate through an oxidative pathway.


Assuntos
Complexos de Coordenação/química , Cobre/química , Clivagem do DNA , Oligopeptídeos/síntese química , Ácido Ascórbico , Complexos de Coordenação/síntese química , DNA Super-Helicoidal , Peróxido de Hidrogênio , Conformação de Ácido Nucleico , Oxirredução , Plasmídeos
16.
Biol Pharm Bull ; 38(1): 96-101, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25744464

RESUMO

IMP-2, a subclass B1 metallo-ß-lactamase (MBL), is a Zn(II)-containing hydrolase. This hydrolase, involved in antibiotic resistance, catalyzes the hydrolysis of the C-N bond of the ß-lactam ring in ß-lactam antibiotics such as benzylpenicillin and imipenem. The crystal structure of IMP-2 MBL from Acinetobacter spp. was determined at 2.3 Å resolution. This structure is analogous to that of subclass B1 MBLs such as IMP-1 and VIM-2. Comparison of the structures of IMP-1 and IMP-2, which have an 85% amino acid identity, suggests that the amino acid substitution at position 68 on a ß-strand (ß3) (Pro in IMP-1 versus Ser in IMP-2) may be a staple factor affecting the flexibility of loop 1 (comprising residues at positions 60-66; EVNGWGV). In the IMP-1 structure, loop 1 adopts an open, disordered conformation. On the other hand, loop 1 of IMP-2 forms a closed conformation in which the side chain of Trp64, involved in substrate binding, is oriented so as to cover the active site, even though there is an acetate ion in the active site of both IMP-1 and IMP-2. Loop 1 of IMP-2 has a more flexible structure in comparison to IMP-1 due to having a Ser residue instead of the Pro residue at position 68, indicating that this difference in sequence may be a trigger to induce a more flexible conformation in loop 1.


Assuntos
Acinetobacter/enzimologia , Proteínas de Bactérias/química , beta-Lactamases/química , Domínio Catalítico , Cristalização , Conformação Proteica , Difração de Raios X
17.
J Sep Sci ; 37(13): 1601-9, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24737618

RESUMO

A simple and efficient method based on magnetic-bead technology has been developed for the enrichment of thiol-containing biomolecules, such as l-glutathione and cysteine-containing peptides. The thiol-binding site on the bead is a mononuclear complex of zinc(II) with 1,4,7,10-tetraazacyclododecane (cyclen); this is linked to a hydrophilic cross-linked agarose coating on a particle that has a magnetic core. All steps for the thiol-affinity separation are conducted in aqueous buffers with 0.10 mL of the magnetic beads in a 1.5 mL microtube. The entire separation protocol for thiol-containing compounds, from addition to elution, requires less than one hour per sample, provided the buffers and the zinc(II)-cyclen-functionalized magnetic beads have been prepared in advance. The thiol-affinity magnetic beads are reusable at least 15 times without a decrease in their thiol-binding ability, and they are stable for six months at room temperature.


Assuntos
Glutationa/isolamento & purificação , Compostos Heterocíclicos/química , Magnetismo/métodos , Zinco/química , Ciclamos , Glutationa/química , Fenômenos Magnéticos , Magnetismo/instrumentação , Peptídeos/química , Peptídeos/isolamento & purificação
18.
Cureus ; 16(4): e57417, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38694683

RESUMO

Boron neutron capture therapy (BNCT) has predominantly been performed for brain tumors or head and neck cancers. Although BNCT is known to be applicable to breast cancer, it has only been performed in a few cases involving thoracic region irradiation with reactor-based BNCT systems. Thus, there are very few reports on the effects of BNCT on the thoracic region and no reports of BNCT for breast cancer with accelerator-based BNCT systems. This paper introduces the world's first clinical study employing an accelerator-based BNCT system targeting recurrent breast cancer after radiation therapy. We aim to assess the efficacy and safety of BNCT, focusing on the dose response in the thoracic region, especially concerning the potential for radiation pneumonitis. Preliminary findings from the first three cases indicate no evidence of radiation pneumonitis within three months post treatment. This study not only establishes a foundation for novel breast cancer treatment options but also contributes significantly to the field of BNCT in the thoracic region.

19.
Cureus ; 16(4): e58006, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38738023

RESUMO

Backgrounds and objectives Renal sinus fat (RSF) is an indicator of obesity-related complications. However, the measurement and imaging process are complicated. For a simple measurement of RSF, we focused on the kidney's shape change caused by RSF accumulation. Thus, this study aimed to investigate whether the anteroposterior diameter of the renal sinus (APDRS) on a computed tomography (CT) axial image is useful for evaluating RSF accumulation. Materials and methods The correlation between APDRS and RSF was investigated in 98 outpatients who underwent abdominal CT. In addition, the correlation between APDRS or RSF and obesity indicators (estimated glomerular filtration rate from serum creatinine levels (eGFRcreat), body mass index (BMI), and visceral adipose tissue (VAT)) was also investigated. We classified patients based on the presence or absence of at least one underlying disease (chronic kidney disease (CKD), cardiovascular diseases (CVD), hypertension, and type 2 diabetes (T2D)) and investigated significant differences between the two groups at APDRS and RSF. The intraclass correlation coefficient (ICC) was also calculated for APDRS. Results There was a strong positive correlation between RSF and APDRS (r = 0.802, P < 0.01). The obesity indicators (eGFRcreat, BMI, and VAT) were correlated with RSF and APDRS (P < 0.01). Out of 98 outpatients, 48 had at least one underlying disease. There were statistically significant differences in APDRS and RSF between the patients with and without at least one of the underlying diseases caused by obesity (P < 0.01). The inter-reader ICC for the measurement of the APDRS was 0.98. Conclusions APDRS on a CT axial image may be useful for the evaluation of RSF accumulation.

20.
IUCrdata ; 9(Pt 5): x240431, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38846558

RESUMO

In the structure of the title complex, [Zn(C4H2FN2O2)(C10H24N4)]ClO4, the zinc(II) ion forms coordination bonds with the four nitro-gen atoms of cyclam (1,4,8,11-tetra-aza-cyclo-tetra-decane or [14]aneN4) as well as with the nitro-gen atom of a deprotonated 5-fluoro-uracil ion (FU-). Cyclam adopts a trans-I type conformation within this structure. The coordination structure of the zinc(II) ion is a square pyramid with a distorted base plane formed by the four nitro-gen atoms of the cyclam. FU- engages in inter-molecular hydrogen bonding with neighboring FU- mol-ecules and with the cyclam mol-ecule.

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