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1.
BMC Geriatr ; 24(1): 250, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38475701

RESUMO

BACKGROUND: An increasing number of older patients require emergency abdominal surgery for acute abdomen. They are susceptible to surgical stress and lose their independence in performing daily activities. Laparoscopic surgery is associated with faster recovery, less postoperative pain, and shorter hospital stay. However, few studies have examined the relationship between laparoscopic surgery and physical functional decline. Thus, we aimed to examine the relationship between changes in physical function and the surgical procedure. METHODS: In this was a single-center, retrospective cohort study, we enrolled patients who were aged ≥ 65 years and underwent emergency abdominal surgery for acute abdomen between January 1, 2019, and December 31, 2021. We assessed their activities of daily living using the Barthel Index. Functional decline was defined as a decrease of ≥ 20 points in Barthel Index at 28 days postoperatively, compared with the preoperative value. We evaluated an association between functional decline and surgical procedures among older patients, using multiple logistic regression analysis. RESULTS: During the study period, 852 patients underwent emergency abdominal surgery. Among these, 280 patients were eligible for the analysis. Among them, 94 underwent laparoscopic surgery, while 186 underwent open surgery. Patients who underwent laparoscopic surgery showed a less functional decline at 28 days postoperatively (6 vs. 49, p < 0.001). After adjustments for other covariates, laparoscopic surgery was an independent preventive factor for postoperative functional decline (OR, 0.22; 95% CI, 0.05-0.83; p < 0.05). CONCLUSIONS: In emergency abdominal surgery, laparoscopic surgery reduces postoperative physical functional decline in older patients. Widespread use of laparoscopic surgery can potentially preserve patient quality of life and may be important for the better development of emergency abdominal surgery.


Assuntos
Abdome Agudo , Laparoscopia , Humanos , Idoso , Estudos de Coortes , Estudos Retrospectivos , Qualidade de Vida , Atividades Cotidianas , Laparoscopia/métodos , Complicações Pós-Operatórias
2.
J Med Chem ; 67(5): 3741-3763, 2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38408347

RESUMO

In research focused on protein-protein interaction (PPI) inhibitors, the optimization process to achieve both high inhibitory activity and favorable physicochemical properties remains challenging. Our previous study reported the discovery of novel and bioavailable Keap1-Nrf2 PPI inhibitor 8 which exhibited moderate in vivo activity in rats. In this work, we present our subsequent efforts to optimize this compound. Two distinct approaches were employed, targeting high energy water molecules and Ser602 as "hot spots" from the anchor with good aqueous solubility, metabolic stability, and membrane permeability. Through ligand efficiency (LE)-guided exploration, we identified two novel inhibitors 22 and 33 with good pharmacokinetics (PK) profiles and more potent in vivo activities, which appear to be promising chemical probes among the existing inhibitors.


Assuntos
Descoberta de Drogas , Fator 2 Relacionado a NF-E2 , Ratos , Animais , Ligação Proteica , Fator 2 Relacionado a NF-E2/metabolismo , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo
3.
SLAS Discov ; 2023 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-37935317

RESUMO

Protein-protein interactions (PPIs) play a crucial role in most biological processes and are important targets in the development of therapeutic agents. However, small molecule drug discovery that targets PPIs remains very challenging. Targeting hot spot residues is considered the best option for inhibiting such interactions, but there are few examples of how knowledge of hot spots can be used in high throughput screening to find hit compounds. A substrate adaptor protein for a ubiquitin ligase complex, Kelch-like ECH-associated protein 1 (Keap1), negatively modulates the expression of genes involved in cellular protection against oxidative stress. Here, we focused on three arginine hot spot residues in the Keap1 substrate binding pocket (Arg380, Arg415, and Arg483), and screened the carboxylic acid library owned by Japan Tobacco Inc. for compounds that interact with the arginine residues in differential scanning fluorescence assays. Furthermore, we identified several small molecule compounds that specifically bind to the Keap1 Kelch domain hot spots by comparing binding to alanine mutant proteins (R380A, R415A, and R483A) with binding to the wild-type protein using surface plasmon resonance (SPR) screening. These compounds inhibited the protein-protein interaction between the Keap1 Kelch domain and the nuclear factor erythroid 2-related factor 2 (Nrf2) peptide, and the ubiquitination of Nrf2 catalyzed by the Cul3/RINGBox 1 E3 ligase. In addition, the binding mode of one compound (Compound 4) was determined by X-ray crystallography after validation of binding by isothermal titration calorimetry, native mass spectrometry, and nuclear magnetic resonance. Compound 4 had favorable thermodynamic properties, and noncovalently bound to Keap1 with a stoichiometry of 1:1. Our results suggest that Compound 4 could potentially be developed into effective therapeutic or preventive agents for a variety of diseases and conditions such as oxidative stress response, inflammation, and carcinogenesis. We believe that the use of a set of complementary biophysical techniques including the SPR assay with single alanine mutant of hot spots provides opportunities to identify hit compounds for developing inhibitors of PPIs.

4.
BMC Surg ; 23(1): 171, 2023 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-37355574

RESUMO

BACKGROUND: Older individuals increasingly require emergency abdominal surgeries. They are susceptible to surgical stress and loss of independence in performing daily activities. We hypothesized that the psoas muscle volume would be significantly associated with postoperative functional decline (FD) in older patients undergoing emergency abdominal surgery and aimed to evaluate the use of the psoas muscle volume on computed tomography (CT) scans. METHODS: A retrospective, single-center study of patients aged ≥ 65 years who had undergone emergency abdominal surgery between January 2019 and June 2021 was performed. We assessed patients' activities of daily living using the Barthel Index. FD was defined as a ≥ 5-point decrease between preoperative and 28-day postoperative values. The psoas muscle volume was measured by CT, which was used for diagnosis, and normalized by height to calculate total psoas muscle index (TPI). We evaluated associations between FD and TPI using receiver operating characteristics (ROC) analysis and multiple logistic regression analysis. RESULTS: Of 238 eligible patients, 71 (29.8%) had clinical postoperative FD. Compared to the non-FD group, the FD group was significantly older and had a higher proportion of females, higher Charlson Comorbidity Index, lower body mass index, higher American Society of Anesthesiology score, lower serum albumin level, and lower TPI. ROC analyses revealed that TPI had the highest area under the curve (0.802; 95% confidence interval [CI], 0.75-0.86). A multivariable logistic regression model revealed that low TPI was an independent predictor of postoperative FD (odds ratio, 0.14; 95% CI, 0.06-0.32). CONCLUSIONS: TPI can predict postoperative FD due to emergency abdominal surgery. Identification of patients who are at high risk of FD before surgery may be useful for enhancing the regionalized system of care for emergency general surgery.


Assuntos
Músculos Psoas , Sarcopenia , Feminino , Humanos , Idoso , Músculos Psoas/diagnóstico por imagem , Estudos Retrospectivos , Atividades Cotidianas , Fatores de Risco , Sarcopenia/complicações , Sarcopenia/diagnóstico , Complicações Pós-Operatórias/epidemiologia
5.
ACS Med Chem Lett ; 14(5): 658-665, 2023 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-37197451

RESUMO

Oxidative stress is one of the causes of progression of chronic kidney disease (CKD). Activation of the antioxidant protein regulator Nrf2 by inhibition of the Keap1-Nrf2 protein-protein interaction (PPI) is of interest as a potential treatment for CKD. We report the identification of the novel and weak PPI inhibitor 7 with good physical properties by a high throughput screening (HTS) campaign, followed by structural and computational analysis. The installation of only methyl and fluorine groups successfully provided the lead compound 25, which showed more than 400-fold stronger activity. Furthermore, these dramatic substituent effects can be explained by the analysis of using isothermal titration calorimetry (ITC). Thus, the resulting 25, which exhibited high oral absorption and durability, would be a CKD therapeutic agent because of the dose-dependent manner for up-regulation of the antioxidant protein heme oxigenase-1 (HO-1) in rat kidneys.

6.
J Biochem ; 173(2): 115-127, 2023 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-36413757

RESUMO

The continuous emergence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) variants associated with the adaptive evolution of the virus is prolonging the global coronavirus disease 2019 (COVID-19) pandemic. The modification of neutralizing antibodies based on structural information is expected to be a useful approach to rapidly combat emerging variants. A dimerized variable domain of heavy chain of heavy chain antibody (VHH) P17 that has highly potent neutralizing activity against SARS-CoV-2 has been reported but the mode of interaction with the epitope remains unclear. Here, we report the X-ray crystal structure of the complex of monomerized P17 bound to the SARS-CoV-2 receptor binding domain (RBD) and investigated the binding activity of P17 toward various variants of concern (VOCs) using kinetics measurements. The structure revealed details of the binding interface and showed that P17 had an appropriate linker length to have an avidity effect and recognize a wide range of RBD orientations. Furthermore, we identified mutations in known VOCs that decrease the binding affinity of P17 and proposed methods for the acquisition of affinity toward the Omicron RBD because Omicron is currently the most predominant VOC. This study provides information for the rational design of effective VHHs for emerging VOCs.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , Dimerização , Epitopos , Cadeias Pesadas de Imunoglobulinas
7.
Commun Biol ; 5(1): 669, 2022 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-35794202

RESUMO

We are amid the historic coronavirus infectious disease 2019 (COVID-19) pandemic. Imbalances in the accessibility of vaccines, medicines, and diagnostics among countries, regions, and populations, and those in war crises, have been problematic. Nanobodies are small, stable, customizable, and inexpensive to produce. Herein, we present a panel of nanobodies that can detect the spike proteins of five SARS-CoV-2 variants of concern (VOCs) including Omicron. Here we show via ELISA, lateral flow, kinetic, flow cytometric, microscopy, and Western blotting assays that our nanobodies can quantify the spike variants. This panel of nanobodies broadly neutralizes viral infection caused by pseudotyped and authentic SARS-CoV-2 VOCs. Structural analyses show that the P86 clone targets epitopes that are conserved yet unclassified on the receptor-binding domain (RBD) and contacts the N-terminal domain (NTD). Human antibodies rarely access both regions; consequently, the clone buries hidden crevasses of SARS-CoV-2 spike proteins that go undetected by conventional antibodies.


Assuntos
COVID-19 , Anticorpos de Domínio Único , Anticorpos Antivirais , Humanos , Glicoproteínas de Membrana/metabolismo , Testes de Neutralização , SARS-CoV-2/genética , Anticorpos de Domínio Único/genética , Glicoproteína da Espícula de Coronavírus/genética , Proteínas do Envelope Viral/metabolismo
8.
J Trauma Acute Care Surg ; 92(5): 873-879, 2022 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-34711794

RESUMO

BACKGROUND: Extravasation on contrast-enhanced computed tomography (CECT) is a helpful indicator of the need for transcatheter arterial embolization (TAE) for pelvic fractures. However, previous reports were inconsistent on cases in which angiography is necessary, even though there is no extravasation on computed tomography. This study aimed to describe and analyze the contradictory findings in cases where extravasation is observed on angiography but not on CECT, to contribute to improved management of patients with pelvic fractures. METHODS: This was a retrospective single-center study. Patients with pelvic fractures who underwent CECT and TAE between 2014 and 2020 were included. We classified the patients into three groups: CECT and angiography with extravasation (CT+Angio+), CECT with no extravasation and angiography with extravasation (CT-Angio+), and CECT with extravasation and angiography without extravasation (CT+Angio-). RESULTS: A total of 113 patients were included in the study: the CT+Angio+ group had 54 patients, CT-Angio+ group, 47; and CT+Angio- group, 12. The CT-Angio+ group had a significantly longer time from arrival to CECT than the CT+Angio+ group (27 minutes vs. 23 minutes, p < 0.05). The CT-Angio+ group had significantly more blood transfusions (fresh frozen plasma, platelets) within 24 hours than the CT+Angio- group did (p < 0.05), and ventilator management days (p < 0.05) and intensive care unit stays (p < 0.05) were significantly longer. CONCLUSION: There was no significant difference in outcomes among the three groups. There was no difference in severity, transfusion volume, or mortality in patients with pelvic fractures needing TAE, classified as CT-Angio+, compared with that of CT+Angio+ patients. Even in the absence of extravasation in the pelvic region on CECT, angiography or TAE may still be necessary. LEVEL OF EVIDENCE: Therapeutic/Care Management, Level IV.


Assuntos
Embolização Terapêutica , Fraturas Ósseas , Angiografia/métodos , Fraturas Ósseas/diagnóstico por imagem , Fraturas Ósseas/terapia , Hemorragia/terapia , Humanos , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/métodos
9.
Aust Crit Care ; 35(1): 66-71, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-33926788

RESUMO

BACKGROUND: Initial fluid resuscitation is presumed to be important for treating shock in the resuscitation phase. However, little is known how quickly and easily a physician could perform a rapid infusion with a syringe. OBJECTIVES: We hypothesised that using a high-flow three-way stopcock (HTS) makes initial fluid resuscitation faster and easier than using a normal-flow three-way stopcock (NTS). METHODS: This was a simulation study with a prospective, nonblinded randomised crossover design. Twenty physicians were randomly assigned into two groups. Each participant used six peripheral intravenous infusion circuits, three with the HTS and the others with the NTS, and three cannulae, 22, 20, and 18 gauge (G). The first group started with the HTS first, while the other started with the NTS first. They were asked to inject the fluid as quick as possible. We compared the time until the participants finished rapid infusions of 500 ml of 0.9% saline and the practitioner's effort. RESULTS: In infusion circuits attached with the 22G cannula, the mean difference using the HTS and the NTS (95% confidence interval [CI]) was 16.30 ml/min (7.65-24.94) (p < 0.01). In those attached with the 20G cannula, the mean difference (95% CI) was 23.47 (12.43-34.51) (p < 0.01). In those attached with the 18G cannula, the mean difference (95% CI) was 42.53 (28.68-56.38) (p < 0.01). CONCLUSIONS: This study revealed that the push-and-pull technique using the HTS was faster, easier, and less tiresome than using the NTS, with a statistically significant difference. In the resuscitation phase, initial and faster infusion is important. If only a single physician or other staff member such as a nurse is attending or does not have accessibility to any other devices in such an environment where medical resources are scarce, performing the push-and-pull technique using the HTS could help a physician to perform fluid resuscitation faster. By setting up the HTS instead of the NTS from the beginning, we would be able to begin fluid resuscitation immediately while preparing other devices.


Assuntos
Ressuscitação , Choque , Estudos Cross-Over , Hidratação/métodos , Humanos , Estudos Prospectivos , Ressuscitação/métodos
10.
Sci Rep ; 11(1): 23880, 2021 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-34903816

RESUMO

Anastomotic leakage after intestinal resection is one of the most serious complications of surgical intervention for hollow viscus injury. Adequate vascular perfusion of the anastomotic site is essential to prevent anastomotic leakage. Near-infrared imaging using indocyanine green (NIR-ICG) is useful for the objective assessment of vascular perfusion. The aim of this study was to evaluate the association of NIR-ICG with intestinal and mesenteric injuries. This was a retrospective, single-center study of patients undergoing surgery for intestinal and mesenteric injuries. NIR-ICG was used to evaluate vascular perfusion. Postoperative complications were assessed between NIR-ICG and non-NIR-ICG groups.The use of NIR-ICG was associated with a lower incidence of Clavien-Dindo grade ≥ III complications with a statistical tendency (p = 0.076). When limited to patients that underwent intestinal resection, the use of NIR-ICG was significantly associated with a lower risk of perioperative complications (p = 0.009). The use of NIR-ICG tended to associate with the lower incidence of postoperative complications after intestinal and mesenteric trauma surgery. NIR-ICG was associated with a significantly lower risk of complications in patients undergoing intestinal resection. The NIR-ICG procedure is simple and quick and is expected to be useful for intestinal and mesenteric trauma.


Assuntos
Fístula Anastomótica/epidemiologia , Procedimentos Cirúrgicos do Sistema Digestório/métodos , Intestinos/cirurgia , Mesentério/cirurgia , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Adulto , Idoso , Procedimentos Cirúrgicos do Sistema Digestório/efeitos adversos , Feminino , Corantes Fluorescentes , Humanos , Verde de Indocianina , Intestinos/lesões , Masculino , Mesentério/lesões , Pessoa de Meia-Idade
12.
Acute Med Surg ; 7(1): e509, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32313662

RESUMO

BACKGROUND: Veno-venous extracorporeal membrane oxygenation (VV-ECMO) is one of the ultimate treatments for acute respiratory failure. However, the effectiveness of ECMO in patients with novel coronavirus disease (COVID-19) is unknown. CASE PRESENTATION: A 72-year-old woman who was a passenger of a cruise ship tested positive for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) while in quarantine on board using throat swab. Three days after admission, her condition deteriorated, and she was subsequently intubated. On day 6, VV-ECMO was introduced. Lopinavir/ritonavir was given; continuous renal replacement therapy was also introduced. On day 10, her chest radiography and lung compliance improved. She was weaned off ECMO on day 12. CONCLUSION: Treatment of severe pneumonia in COVID-19 by ECMO should recognize lung plasticity considering time to ECMO introduction and interstitial biomarkers. In Japan, centralization of ECMO patients has not been sufficient. Thus, we suggest nationwide centralization and further research to respond to the crisis caused by COVID-19.

13.
World J Emerg Surg ; 14: 35, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31346347

RESUMO

Background: Resuscitative endovascular balloon occlusion of the aorta (REBOA) for patients with traumatic torso hemorrhagic shock is available to keep a minimum level of circulatory status as a bridge to definitive therapy. However, the trajectory for placement of REBOA in the aorta has not yet been clearly defined. Methods: We conducted a retrospective observational cohort study in the two tertiary critical care and emergency center from December 2014 to October 2018. A total of 28 patients who underwent focused assessment with sonography for trauma (FAST) were studied via contrast computed tomography (CT), and 27 were analyzed. Results: We divided patients into two groups based on our CT findings. The REBOA deflate group included 16 patients, and the inflate group included 11 patients. The median trace value (interquartile range) of the blood vessel center line from the common femoral artery to the tip of REBOA (blood vessel length) and the length of REBOA itself from the common femoral artery to the tip of REBOA (REBOA insertion length) were 56.2 cm (54.5-57.2) and 55.2 cm (54.2-55.6), respectively (p < 0.0001) for the deflated group, and 51.4 cm (42.1-56.6) and 50.3 cm (42.3-55.0) (p = 0.594), respectively, for the inflated group. Conclusions: If REBOA was deflated, it was placed 1.0 cm longer than the insertion length of REBOA catheter itself, but that was not the case when inflating REBOA. The individual difference was large to the extent that the balloon inflated and the extent to which the balloon was pushed back toward the caudal depending on the degree of blood pressure. Further studies would be needed to validate the study findings.


Assuntos
Pontos de Referência Anatômicos , Aorta/anatomia & histologia , Oclusão com Balão/métodos , Cateterismo/métodos , Adulto , Oclusão com Balão/normas , Cateterismo/normas , Estudos de Coortes , Procedimentos Endovasculares/métodos , Procedimentos Endovasculares/normas , Feminino , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Ressuscitação/métodos , Ressuscitação/normas , Estudos Retrospectivos
14.
J Cardiothorac Surg ; 14(1): 88, 2019 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-31060587

RESUMO

INTRODUCTION: The use of veno-venous extracorporeal membrane oxygenation (VV-ECMO) in trauma patients has been controversial, but VV-ECMO plays a crucial role when the lungs are extensively damaged and when conventional management has failed. VV-ECMO provides adequate tissue oxygenation and an opportunity for lung recovery. However, VV-ECMO remains contraindicated in patients with a risk of bleeding because of systemic anticoagulation during the treatment. The most important point is controlling the bleeding from severe trauma. CASE: A 32-year-old male experienced blunt trauma due to a traffic accident. He presented with bilateral hemopneumothorax and bilateral flail chest. We performed emergency thoracotomy for active bleeding and established circulatory stability. After surgery, the oxygenation deteriorated under mechanical ventilation, so we decided to establish VV-ECMO. However, bleeding from the bilateral lung contusions increased after VV-ECMO was established, and the patient was switched to heparin-free ECMO. After conversion, we could control the bronchial bleeding, especially the lung hematomas, and the oxygenation recovered. The patient was discharged without significant complications. VV-ECMO and mechanical ventilation were stopped on days 10 and 11, respectively. He was discharged from the ICU on day 15. CONCLUSION: When we consider the use of ECMO for patients with uncontrollable, severe bleeding caused by blunt trauma, it may be necessary to use a higher flow setting for heparin-free ECMO than typically used for patients without trauma to prevent thrombosis.


Assuntos
Oxigenação por Membrana Extracorpórea/métodos , Hemorragia/terapia , Traumatismos Torácicos/terapia , Ferimentos não Penetrantes/terapia , Acidentes de Trânsito , Adulto , Tórax Fundido/terapia , Hemopneumotórax/terapia , Hemorragia/etiologia , Humanos , Masculino , Motocicletas , Respiração Artificial , Toracotomia
15.
Sci Rep ; 8(1): 17374, 2018 11 26.
Artigo em Inglês | MEDLINE | ID: mdl-30478402

RESUMO

Retinoic acid-related orphan receptor gamma (RORγ) plays pivotal roles in autoimmune diseases by controlling the lineage of interleukin 17 (IL-17)-producing CD4+ T cells (Th17 cells). Structure-based drug design has proven fruitful in the development of inhibitors targeting the ligand binding domain (LBD) of RORγ. Here, we present the crystal structure of a novel RORγ inhibitor co-complex, in the presence of a corepressor (CoR) peptide. This ternary complex with compound T reveals the structural basis for an inhibitory mechanism different from the previously reported inverse agonist. Compared to the inverse agonist, compound T induces about 2 Šshift of helix 5 (H5) backbone and side-chain conformational changes of Met365 on H5. These conformational changes correlate to reduced CoR peptide binding to RORγ-LBD in the presence of compound T, which suggests that the shift of H5 is responsible. This crystal structure analysis will provide useful information for the development of novel and efficacious drugs for autoimmune disorders.


Assuntos
Proteínas Correpressoras/metabolismo , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/química , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Domínios Proteicos/fisiologia , Doenças Autoimunes/metabolismo , Humanos , Interleucina-17/metabolismo , Peptídeos/metabolismo , Ligação Proteica , Relação Estrutura-Atividade , Células Th17/metabolismo
16.
Genes Cells ; 22(6): 535-551, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28493531

RESUMO

Retinoid-related orphan receptor gamma (RORγ) directly controls the differentiation of Th17 cell and the production of interleukin-17, which plays an integral role in autoimmune diseases. To obtain insight into RORγ, we have determined the first crystal structure of a ternary complex containing RORγ ligand-binding domain (LBD) bound with a novel synthetic inhibitor and a repressor peptide, 22-mer peptide from silencing mediator of retinoic acid and thyroid hormone receptor (SMRT). Comparison of a binary complex of nonliganded (apo) RORγ-LBD with a nuclear receptor co-activator (NCoA-1) peptide has shown that our inhibitor displays a unique mechanism different from those caused by natural inhibitor, ursolic acid (UA). The compound unprecedentedly induces indirect disruption of a hydrogen bond between His479 on helix 11 (H11) and Tyr502 on H12, which is crucial for active conformation. This crystallographic study will allow us to develop novel synthetic compounds for autoimmune disease therapy.


Assuntos
Correpressor 2 de Receptor Nuclear/metabolismo , Coativador 1 de Receptor Nuclear/metabolismo , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Sítios de Ligação , Humanos , Ligação de Hidrogênio , Modelos Moleculares , Mutação , Correpressor 2 de Receptor Nuclear/agonistas , Correpressor 2 de Receptor Nuclear/química , Correpressor 2 de Receptor Nuclear/genética , Coativador 1 de Receptor Nuclear/química , Coativador 1 de Receptor Nuclear/genética , Fragmentos de Peptídeos , Ligação Proteica , Conformação Proteica , Triterpenos/farmacologia
17.
J Biochem ; 150(5): 563-8, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21840922

RESUMO

Old yellow enzyme (OYE) is an NADPH oxidoreductase capable of reducing a variety of compounds. It contains flavin mononucleotide (FMN) as a prosthetic group. A ternary complex structure of OYE from Trypanosoma cruzi (TcOYE) with FMN and one of the substrates, p-hydroxybenzaldehyde, shows a striking movement around the active site upon binding of the substrate. From a structural comparison of other OYE complexed with 12-oxophytodienoate, we have constructed a complex structure with another substrate, prostaglandin H(2) (PGH(2)), to provide a proposed stereoselective reaction mechanism for the reduction of PGH(2) to prostaglandin F(2α) by TcOYE.


Assuntos
Dinoprosta/metabolismo , NADPH Desidrogenase/química , NADPH Desidrogenase/metabolismo , Proteínas de Protozoários/química , Proteínas de Protozoários/metabolismo , Trypanosoma cruzi/enzimologia , Benzaldeídos/química , Benzaldeídos/metabolismo , Domínio Catalítico , Cristalografia por Raios X , Dinoprosta/química , Mononucleotídeo de Flavina/química , Mononucleotídeo de Flavina/metabolismo , NADPH Desidrogenase/genética , Proteínas de Protozoários/genética
18.
J Plant Physiol ; 168(16): 1972-9, 2011 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-21680053

RESUMO

The cell wall protein fraction (CWP) isolated from the biocontrol agent Pythium oligandrum induces defense reactions in tomato. CWP contains two novel elicitin-like proteins, POD-1 and POD-2, both with seven cysteines. To determine the essential structure in the defense-eliciting components of CWP, five fractions (F1, F2, F3, F4 and F5) were fractionated from CWP using cation chromatography and their components and disulfide bond compositions were analyzed. The expression levels of three defense-related genes (PR-6, LeCAS and PR-2b) were determined in tomato roots treated with each of the five fractions. Of the five fractions, F4 containing a heterohexamer of POD-1 and POD-2, and F5 containing a homohexamer of POD-1, both with disulfide bonds formed between all cysteine residues, induced the expression of three genes. F4 treatment also induced the accumulation of ethylene in tomato. The predicted three-dimensional structures of POD-1 and POD-2, and the results of SEC and MALDI-TOF MS analyses suggest that F4 consists of three POD-1 and POD-2 disulfide-bonded heterodimers that interleave into a hexameric ring through noncovalent association. These results suggest that this structure, which F5 also appears to form, is essential for stimulating defense responses in tomato.


Assuntos
Pythium/fisiologia , Solanum lycopersicum/genética , Solanum lycopersicum/imunologia , Parede Celular/metabolismo , Etilenos/metabolismo , Solanum lycopersicum/fisiologia , Modelos Moleculares , Controle Biológico de Vetores , Imunidade Vegetal/genética , Raízes de Plantas/genética , Raízes de Plantas/imunologia , Raízes de Plantas/fisiologia , Multimerização Proteica , Pythium/genética , Plântula/genética , Plântula/imunologia , Plântula/fisiologia , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
19.
J Synchrotron Radiat ; 18(1): 66-9, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21169695

RESUMO

Old yellow enzyme (OYE) is an NADPH oxidoreductase which contains flavin mononucleotide as prosthetic group. The X-ray structures of OYE from Trypanosoma cruzi (TcOYE) which produces prostaglandin (PG) F(2α) from PGH(2) have been determined in the presence or absence of menadione. The binding motif of menadione, known as one of the inhibitors for TcOYE, should accelerate the structure-based development of novel anti-chagasic drugs that inhibit PGF(2α) production specifically.


Assuntos
Hidroxiprostaglandina Desidrogenases/antagonistas & inibidores , NADPH Desidrogenase/antagonistas & inibidores , NADPH Desidrogenase/química , Trypanosoma cruzi/enzimologia , Vitamina K 3/química , Sítios de Ligação , Cristalografia por Raios X , Mononucleotídeo de Flavina/química , Hidroxiprostaglandina Desidrogenases/metabolismo , Modelos Moleculares , Vitamina K 3/farmacologia
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