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DEAD box helicase proteins are a family of RNA helicases that participate in various RNA metabolisms such as RNA unwinding, RNA processing, and RNPase activities. A particular DEAD box protein, the DDX53 protein, is primarily expressed in cancer cells and plays a crucial role in tumorigenesis. Numerous studies have revealed that DDX53 interacts with various microRNA and Histone deacetylases. However, its molecular structure and the detailed binding interaction between DDX53 and microRNA or HDAC is still unclear. In this study, we used X-ray crystallography to investigate the 3D structure of the hlicase C-terminal domain of DDX53, and successfully determined its crystal structure at a resolution of 1.97 Å. Subsequently, a functional analysis of RNA was conducted by examining the binding properties thereof with DDX53 by transmission electron microscopy and computing-based molecular docking simulation. The defined 3D model of DDX53 not only provides a structural basis for the fundamental understanding of DDX53 but is also expected to contribute to the field of anti-cancer drug discovery such as structure-based drug discovery and computer-aided drug design.
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ADN Helicasas , MicroARNs , Humanos , Simulación del Acoplamiento Molecular , ARN Helicasas , Carcinogénesis , ARN Helicasas DEAD-boxRESUMEN
BACKGROUND: Clinically relevant postoperative pancreatic fistula (CR-POPF) is an inherently severe risk of pancreatic resection. Previous research has proposed models that identify risk factors and predict CR-POPF, although these are rarely applicable to minimally invasive pancreaticoduodenectomy (MIPD). This study aimed to evaluate the individual risks of CR-POPF and to propose a nomogram for predicting POPF in MIPD. PATIENTS AND METHODS: We retrospectively reviewed the medical records of 429 patients who underwent MIPD. In the multivariate analysis, the Akaike information criterion stepwise logistic regression method was used to select the final model to develop the nomogram. RESULTS: Of 429 patients, 53 (12.4%) experienced CR-POPF. On multivariate analysis, pancreatic texture (p = 0.001), open conversion (p = 0.008), intraoperative transfusion (p = 0.011), and pathology (p = 0.048) were identified as independent predictors of CR-POPF. The nomogram was developed based on patient, pancreatic, operative, and surgeon factors by using the following four additional clinical factors as variables: American Society of Anesthesiologists class ≥ III, size of pancreatic duct, type of surgical approach, and < 40 cases of MIPD experience. CONCLUSIONS: A multidimensional nomogram was developed to predict CR-POPF after MIPD. This nomogram and calculator can help surgeons anticipate, select, and manage critical complications.
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Fístula Pancreática , Pancreaticoduodenectomía , Humanos , Fístula Pancreática/diagnóstico , Fístula Pancreática/etiología , Pancreaticoduodenectomía/efectos adversos , Pancreaticoduodenectomía/métodos , Nomogramas , Estudios Retrospectivos , Páncreas/cirugía , Factores de Riesgo , Complicaciones Posoperatorias/patologíaRESUMEN
A highly efficient and regioselective approach to a novel 1,2,4-triazole-fused N-heterocyclic scaffold, pyrrolo[1,2-a][1,2,4]triazolo[3,4-c]pyrazine, was established by base-promoted reaction of pyrrole-2-carbonitrile-derived substrate with acyl hydrazide where domino double ring closures comprised of enamine formation, attack on nitrile, and cyclodehydration enabled sequential construction of pyrazine and 1,2,4-triazole ring systems with formation of three C-N bonds.
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OBJECTIVES: No previous studies have explored the effect of folate deficiency on the severity of osteoarthritis (OA). Therefore, we investigated the relationship between folate level and features on knee and hand radiographs in a large, population-based OA cohort. METHODS: Among 9,260 subjects enrolled in the Dong-gu study, 2,489 who had knee and hand joint radiographs were included. Of these, subjects with a history of amputation or total knee replacement were excluded. Serum folate levels were measured using blood samples collected at the time of enrolment and stored. A semi-quantitative system was used to grade the severity of hand and knee x-ray changes. Linear regression was performed to assess relationships between serum folate levels and knee and hand radiographic scores after adjusting for age, sex, body mass index, smoking, alcohol consumption, education, physical activity, occupation, vitamin D, and ferritin. RESULTS: A total of 2,322 subjects were recruited. After adjusting for confounders, participants with folate deficiency (<4 ng/mL) had higher total (p<0.001), osteophyte (p<0.001), joint space narrowing (p=0.002), tibial attrition (p<0.001), and sclerosis (p=0.005) scores for knee joint radiographs compared to participants with a normal folate level. After adjusting for confounders, the radiographic scores for hand joints did not differ between the groups. CONCLUSIONS: Folate deficiency is associated with increased radiographic severity of OA in knee joints, but not in hand joints. Further studies are needed to explore the differential effects of folate on the severity of knee and hand OA.
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Articulaciones de la Mano , Osteoartritis de la Rodilla , Humanos , Osteoartritis de la Rodilla/diagnóstico por imagen , Articulaciones de la Mano/diagnóstico por imagen , Articulación de la Rodilla/diagnóstico por imagen , Mano/diagnóstico por imagen , Ácido FólicoRESUMEN
BACKGROUND: Evidence of the advantages of robotic pancreaticoduodenectomy (RPD) over laparoscopic pancreaticoduodenectomy (LPD) is limited. Thus, this study aimed to compare the surgical outcomes of laparoscopic reconstruction L-recon) versus robotic reconstruction (R-recon) in patients with soft pancreas and small pancreatic duct. METHOD: Among 429 patients treated with minimally invasive pancreaticoduodenectomy (MIPD) between October 2012 and June 2020 by three surgeons at three institutions, 201 patients with a soft pancreas and a small pancreatic duct (< 3 mm) were included in this study. RESULTS: Sixty pairs of patients who underwent L-recon and R-recon were selected after propensity score matching. The perioperative outcomes were comparable between the reconstruction approaches, with comparable clinically relevant postoperative pancreatic fistula (CR-POPF) rates (15.0% [L-recon] vs. 13.3% [R-recon]). The sub-analysis according to the type of MIPD procedure also showed comparable outcomes, but only a significant difference in postoperative hospital stay was identified. During the learning curve analysis using the cumulative summation by operation time (CUSUMOT), two surgeons who performed both L-recon and R-recon procedures reached their first peak in the CUSUMOT graph earlier for the R-recon group than for the L-recon group (i.e., 20th L-recon case and third R-recon case of surgeon A and 43rd L-recon case and seventh R-recon case of surgeon B). Surgeon C, who only performed R-recon, demonstrated the first peak in the 22nd case. The multivariate regression analysis for risk factors of CR-POPF showed that the MIPD procedure type, as well as other factors, did not have any significant effect. CONCLUSION: Postoperative pancreatic fistula rates and the overall perioperative outcomes of L-recon and R-recon were comparable in patients with soft-textured pancreas and small pancreatic duct treated by experienced surgeons.
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Laparoscopía , Procedimientos Quirúrgicos Robotizados , Humanos , Pancreaticoduodenectomía/efectos adversos , Pancreaticoduodenectomía/métodos , Fístula Pancreática/cirugía , Procedimientos Quirúrgicos Robotizados/efectos adversos , Puntaje de Propensión , Páncreas/cirugía , Conductos Pancreáticos/cirugía , Laparoscopía/métodos , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/cirugía , Estudios RetrospectivosRESUMEN
BACKGROUND: Osteoporosis is one of the diseases that requires early screening and detection for its management. Common clinical tools and machine-learning (ML) models for screening osteoporosis have been developed, but they show limitations such as low accuracy. Moreover, these methods are confined to limited risk factors and lack individualized explanation. OBJECTIVE: The aim of this study was to develop an interpretable deep-learning (DL) model for osteoporosis risk screening with clinical features. Clinical interpretation with individual explanations of feature contributions is provided using an explainable artificial intelligence (XAI) technique. METHODS: We used two separate data sets: the National Health and Nutrition Examination Survey data sets from the United States (NHANES) and South Korea (KNHANES) with 8274 and 8680 respondents, respectively. The study population was classified according to the T-score of bone mineral density at the femoral neck or total femur. A DL model for osteoporosis diagnosis was trained on the data sets and significant risk factors were investigated with local interpretable model-agnostic explanations (LIME). The performance of the DL model was compared with that of ML models and conventional clinical tools. Additionally, contribution ranking of risk factors and individualized explanation of feature contribution were examined. RESULTS: Our DL model showed area under the curve (AUC) values of 0.851 (95% CI 0.844-0.858) and 0.922 (95% CI 0.916-0.928) for the femoral neck and total femur bone mineral density, respectively, using the NHANES data set. The corresponding AUC values for the KNHANES data set were 0.827 (95% CI 0.821-0.833) and 0.912 (95% CI 0.898-0.927), respectively. Through the LIME method, significant features were induced, and each feature's integrated contribution and interpretation for individual risk were determined. CONCLUSIONS: The developed DL model significantly outperforms conventional ML models and clinical tools. Our XAI model produces high-ranked features along with the integrated contributions of each feature, which facilitates the interpretation of individual risk. In summary, our interpretable model for osteoporosis risk screening outperformed state-of-the-art methods.
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Aprendizaje Profundo , Osteoporosis , Humanos , Inteligencia Artificial , Encuestas Nutricionales , Osteoporosis/diagnósticoRESUMEN
BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS) virus is an emerging infectious virus which causes severe hemorrhage, thrombocytopenia, and leukopenia, with a high fatality rate. Since there is no approved therapeutics or vaccines for SFTS, early diagnosis is essential to manage this infectious disease. METHODS: Here, we tried to detect SFTS virus in serum samples from SFTS patients by proteomic analysis. Firstly, in order to obtain the reference MS/MS spectral data of SFTS virus, medium from infected Vero cell culture was used for shotgun proteomic analysis. Then, tryptic peptides in sera from SFTS patients were confirmed by comparative analysis with the reference MS/MS spectral data of SFTS virus. RESULTS: Proteomic analysis of culture medium successfully discovered tryptic peptides from all the five antigen proteins of SFTS virus. The comparative spectral analysis of sera of SFTS patients revealed that the N-terminal tryptic peptide of the nucleocapsid (N) protein is the major epitope of SFTS virus detected in the patient samples. The prevalence of the peptides was strongly correlated with the viral load in the clinical samples. CONCLUSIONS: Proteomic analysis of SFTS patient samples revealed that nucleocapsid (N) protein is the major antigen proteins in sera of SFTS patients and N-terminal tryptic peptide of the N protein might be a useful proteomic target for direct detection of SFTS virus. These findings suggest that proteomic analysis could be an alternative tool for detection of pathogens in clinical samples and diagnosis of infectious diseases.
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BACKGROUND: Alcohol consumption is a major risk factor for esophageal cancer; however, a high incidence of esophageal cancer is observed particularly among Eastern Asians, although they consume relatively less alcohol, presumably due to the high frequency of aldehyde dehydrogenase 2 (ALDH2) rs671 polymorphisms. Nevertheless, the association between ALDH2 polymorphisms and esophageal cancer remains under debate. In the present study, we evaluated the association between ALDH2 rs671 polymorphisms and the risk of esophageal cancer in the South Korean population. METHODS: This study included 783 hospital based-cases and 8732 population-based controls. Information on smoking history and alcohol consumption was obtained from the medical records or interview questionnaires. Age-adjusted logistic regression analysis was performed to assess the association between ALDH2 rs671 polymorphisms and esophageal cancer. RESULTS: Odds ratios (ORs) for esophageal cancer in men with GA and AA genotypes were 2.75 (95% confidence interval [CI]: 2.34-3.23) and 0.08 (95% CI: 0.00-0.35), respectively; whereas, in women, these ratios were 2.99 (95% CI: 1.43-6.34) and 6.18 (95% CI: 1.40-19.62), respectively, taking subjects with the ALDH2 GG genotype as a reference. In men, the association between ALDH2 polymorphisms and esophageal cancer was modified by alcohol consumption. CONCLUSION: In Eastern Asians, ALDH2 rs671 polymorphisms are associated with esophageal cancer, which may be linked to acetaldehyde accumulation.
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Aldehído Deshidrogenasa Mitocondrial/genética , Neoplasias Esofágicas/genética , Predisposición Genética a la Enfermedad , Polimorfismo Genético , Anciano , Estudios de Casos y Controles , Neoplasias Esofágicas/etiología , Femenino , Genotipo , Humanos , Masculino , Persona de Mediana Edad , RiesgoRESUMEN
Microtubule-associated protein (MAP) 2 has been perceived as a static cytoskeletal protein enriched in neuronal dendritic shafts. Emerging evidence indicates dynamic functions for various MAPs in activity-dependent synaptic plasticity. However, it is unclear how MAP2 is associated with synaptic plasticity mechanisms. Here, we demonstrate that specific silencing of high-molecular-weight MAP2 in vivo abolished induction of long-term potentiation (LTP) in the Schaffer collateral pathway of CA1 pyramidal neurons and in vitro blocked LTP-induced surface delivery of AMPA receptors and spine enlargement. In mature hippocampal neurons, we observed rapid translocation of a subpopulation of MAP2, present in dendritic shafts, to spines following LTP stimulation. Time-lapse confocal imaging showed that spine translocation of MAP2 was coupled with LTP-induced spine enlargement. Consistently, immunogold electron microscopy revealed that LTP stimulation of the Schaffer collateral pathway promoted MAP2 labeling in spine heads of CA1 neurons. This translocation depended on NMDA receptor activation and Ras-MAPK signaling. Furthermore, LTP stimulation led to an increase in surface-expressed AMPA receptors specifically in the neurons with MAP2 spine translocation. Altogether, this study indicates a novel role for MAP2 in LTP mechanisms and suggests that MAP2 participates in activity-dependent synaptic plasticity in mature hippocampal networks.
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Región CA1 Hipocampal/citología , Región CA1 Hipocampal/metabolismo , Potenciación a Largo Plazo/fisiología , Proteínas Asociadas a Microtúbulos/metabolismo , Células Piramidales/metabolismo , Animales , Células Cultivadas , Espinas Dendríticas/metabolismo , Espinas Dendríticas/ultraestructura , Técnicas In Vitro , Sistema de Señalización de MAP Quinasas , Masculino , Ratones Endogámicos C57BL , Microscopía Inmunoelectrónica , Proteínas Asociadas a Microtúbulos/antagonistas & inhibidores , Proteínas Asociadas a Microtúbulos/genética , Plasticidad Neuronal/fisiología , Transporte de Proteínas , Células Piramidales/ultraestructura , Interferencia de ARN , ARN Interferente Pequeño/genética , Ratas , Receptores AMPA/metabolismoRESUMEN
Cytological examination of urine is the most widely used noninvasive pathologic screen for bladder urothelial carcinoma (BLCA); however, inadequate diagnostic accuracy remains a major challenge. We performed mass spectrometry-based proteomic analysis of urine samples of ten patients with BLCA and ten paired patients with benign urothelial lesion (BUL) to identify ancillary proteomic markers for use in liquid-based cytology (LBC). A total of 4,839 proteins were identified and 112 proteins were confirmed as expressed at significantly different levels between the two groups. We also performed an independent proteomic profiling of tumor tissue samples where we identified 7,916 proteins of which 758 were differentially expressed. Cross-platform comparisons of these data with comparative mRNA expression profiles from The Cancer Genome Atlas identified four putative candidate proteins, AHNAK, EPPK1, MYH14 and OLFM4. To determine their immunocytochemical expression levels in LBC, we examined protein expression data from The Human Protein Atlas and in-house FFPE samples. We further investigated the expression of the four candidate proteins in urine cytology samples from two independent validation cohorts. These analyses revealed AHNAK as a unique intracellular protein differing in immunohistochemical expression and subcellular localization between tumor and non-tumor cells. In conclusion, this study identified a new biomarker, AHNAK, applicable to discrimination between BLCA and BUL by LBC. To our knowledge, the present study provides the first identification of a clinical biomarker for LBC based on in-depth proteomics.
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Biomarcadores de Tumor/metabolismo , Técnicas Citológicas/métodos , Proteínas de la Membrana/metabolismo , Proteínas de Neoplasias/metabolismo , Proteómica/métodos , Neoplasias de la Vejiga Urinaria/diagnóstico , Neoplasias de la Vejiga Urinaria/metabolismo , Urotelio/patología , Anciano , Anciano de 80 o más Años , Femenino , Formaldehído , Humanos , Masculino , Persona de Mediana Edad , Adhesión en Parafina , Proteoma/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Curva ROC , Reproducibilidad de los Resultados , Fijación del Tejido , Neoplasias de la Vejiga Urinaria/patología , Flujo de TrabajoRESUMEN
O-Glycosylation occurs in recombinant proteins produced by CHO cells, but this phenomenon has not been studied extensively. Here, we report that rituximab is an O-linked N-acetyl-glucosaminylated (O-GlcNAcylated) protein and the production of rituximab is increased by thiamet G, an inhibitor of O-GlcNAcase. The production of rituximab doubled with OGA inhibition and decreased with O-GlcNAc transferase inhibition. O-GlcNAc-specific antibody and metabolic labelling with azidO-GlcNAc confirmed the increased O-GlcNAcylation with thiamet G. Protein mass analysis revealed that serine 7, 12, and 14 of the rituximab light chain were O-GlcNAcylated. S12A mutation of the light chain decreased rituximab stability and failed to increase the production with thiamet G without any significant changes of mRNA level. Cytotoxicity and thermal stability assays confirmed that there were no differences in the biological and physical properties of rituximab produced by thiamet G treatment. Therefore, thiamet G treatment improves the production of rituximab without significantly altering its function.
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Mutación Missense , N-Acetilglucosaminiltransferasas/antagonistas & inhibidores , Piranos/farmacología , Rituximab , Tiazoles/farmacología , Sustitución de Aminoácidos , Animales , Células CHO , Cricetulus , Glicosilación/efectos de los fármacos , Humanos , N-Acetilglucosaminiltransferasas/metabolismo , Rituximab/biosíntesis , Rituximab/genéticaRESUMEN
The plant protein production system is a platform that can not only reduce production costs but also produce monoclonal antibodies that do not have the risk of residual proteins from the host. However, due to the difference between post-translational processes in plants and animals, there may be a modification in the Fab region of the monoclonal antibody produced in the plant; thus, it is necessary to compare the antigen affinity of this antibody with that of the prototype. In this study, ofatumumab, a fully human anti-CD20 IgG1κ monoclonal antibody used for its non-cross resistance to rituximab, was expressed in Nicotiana benthamiana, and its affinities and efficacies were compared with those of native ofatumumab produced from CHO cells. Two forms of plant ofatumumab (with or without HDEL-tag) were generated and their production yields were compared. The HDEL-tagged ofatumumab was more expressed in plants than the form without HDEL-tag. The specificity of the target recognition of plant-derived ofatumumab was confirmed by mCherry-CD20-expressing HEK cells via immuno-staining, and the capping of CD20 after ofatumumab binding was also confirmed using Ramos B cells. In the functional equivalence tests, the binding affinities and complement-dependent cell cytotoxicity efficacy of plant-ofatumumab-HDEL and plant-ofatumumab without HDEL were significantly reduced compared to those of CHO-derived ofatumumab. Therefore, we suggest that although ofatumumab is not a good candidate as a template for plant-derived monoclonal antibodies because of its decreased affinity when produced in plants, it is an interesting target to study the differences between post-translational modifications in mammals and plants.
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Anticuerpos Monoclonales Humanizados/genética , Fragmentos Fab de Inmunoglobulinas/química , Nicotiana/metabolismo , Hojas de la Planta/metabolismo , Animales , Anticuerpos Monoclonales Humanizados/química , Anticuerpos Monoclonales Humanizados/metabolismo , Antígenos CD20/metabolismo , Antineoplásicos/química , Antineoplásicos/metabolismo , Apoptosis , Linfocitos B , Células CHO , Muerte Celular/efectos de los fármacos , Línea Celular Tumoral , Cricetulus , Citotoxicidad Inmunológica/efectos de los fármacos , Células HEK293 , Humanos , Conformación Proteica , Rituximab/metabolismoAsunto(s)
Fístula Pancreática , Pancreaticoduodenectomía , Humanos , Pancreaticoduodenectomía/efectos adversos , Pancreaticoduodenectomía/métodos , Fístula Pancreática/diagnóstico , Fístula Pancreática/etiología , Páncreas/cirugía , Pancreatectomía , Anastomosis Quirúrgica , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/cirugíaRESUMEN
BACKGROUND: Outer membrane vesicles (OMVs) of Acinetobacter baumannii are cytotoxic and elicit a potent innate immune response. OMVs were first identified in A. baumannii DU202, an extensively drug-resistant clinical strain. Herein, we investigated protein components of A. baumannii DU202 OMVs following antibiotic treatment by proteogenomic analysis. METHODS: Purified OMVs from A. baumannii DU202 grown in different antibiotic culture conditions were screened for pathogenic and immunogenic effects, and subjected to quantitative proteomic analysis by one-dimensional electrophoresis and liquid chromatography combined with tandem mass spectrometry (1DE-LC-MS/MS). Protein components modulated by imipenem were identified and discussed. RESULTS: OMV secretion was increased > twofold following imipenem treatment, and cytotoxicity toward A549 human lung carcinoma cells was elevated. A total of 277 proteins were identified as components of OMVs by imipenem treatment, among which ß-lactamase OXA-23, various proteases, outer membrane proteins, ß-barrel assembly machine proteins, peptidyl-prolyl cis-trans isomerases and inherent prophage head subunit proteins were significantly upregulated. CONCLUSION: In vitro stress such as antibiotic treatment can modulate proteome components in A. baumannii OMVs and thereby influence pathogenicity.
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The periplasmic domain of OmpA from Acinetobacter baumannii (AbOmpA-PD) binds to diaminopimelate and anchors the outer membrane to the peptidoglycan layer in the cell wall. Although the crystal structure of AbOmpA-PD with its ligands has been reported, the mechanism of ligand-mediated folding of AbOmpA remains elusive. Here, we report that in vitro refolded apo-AbOmpA-PD in the absence of ligand exists as a mixture of two partially folded forms in solution: mostly unfolded (apo-state I) and hololike (apo-state II) states. Binding of the diaminopimelate or glycine ligand induced complete folding of AbOmpA-PD. The apo-state I was highly flexible and contained some secondary structural elements, whereas the apo-state II closely resembled the holo-state in terms of both structure and backbone dynamics, except for the ligand-binding region. 15N-relaxation-dispersion analyses for apo-state II revealed substantial motion on a millisecond timescale of residues in the H3 helix near the ligand-binding site, with this motion disappearing upon ligand binding. These results provide an insight into the ligand-mediated folding mechanism of AbOmpA-PD in solution.
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Proteínas de la Membrana Bacteriana Externa/metabolismo , Acinetobacter baumannii , Secuencia de Aminoácidos , Proteínas de la Membrana Bacteriana Externa/química , Proteínas de la Membrana Bacteriana Externa/genética , Cromatografía en Gel , Dicroismo Circular , Escherichia coli , Fluorometría , Glicina/química , Glicina/metabolismo , Simulación de Dinámica Molecular , Método de Montecarlo , Resonancia Magnética Nuclear Biomolecular , Unión Proteica , Dominios Proteicos , Pliegue de Proteína , SolucionesRESUMEN
3,6-Anydro-l-galatonate cycloisomerase (ACI) catalyzes the cycloisomerization of a 3,6-anhydro-l-galactonic acid known as a novel metabolite in agarolytic bacteria. Here, we present 3-D structures of ACI from Vibrio sp. strain EJY3 (VejACI) in native and mutant forms at 2.2 Å and 2.6 Å resolutions, respectively. The enzyme belongs to the mandelate racemase subgroup of the enolase superfamily catalyzing common ß-elimination reactions by α-carbon deprotonation of substrates. The structure of VejACI revealed a notable 20s loop region in the capping domain, which can be a highly conserved structural motif in ACI homologs of agar metabolism. By comparing mutant (mVejAC/H300 N) and native VejACI structures, we identified a conformational change of Ile142 in VejACI that causes spatial expansion in the binding pocket. These observations imply that Ile142 and the 20s loop play important roles in enzymatic reactivity and substrate specificity. The structural phylogenetic analysis of the enolase superfamily including ACIs revealed sequential, structural, and functional relationships related to the emergence of novel substrate specificity.
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Galactosa/análogos & derivados , Modelos Químicos , Modelos Moleculares , Fosfopiruvato Hidratasa/química , Fosfopiruvato Hidratasa/ultraestructura , Sitios de Unión , Simulación por Computador , Activación Enzimática , Galactosa/química , Unión Proteica , Conformación Proteica , Dominios Proteicos , Relación Estructura-Actividad , Especificidad por SustratoRESUMEN
The atomic structure of a bacterial aryl acylamidase (EC 3.5.1.13; AAA) is reported and structural features are investigated to better understand the catalytic profile of this enzyme. Structures of AAA were determined in its native form and in complex with the analgesic acetanilide, p-acetaminophenol, at 1.70 Å and 1.73 Å resolutions, respectively. The overall structural fold of AAA was identified as an α/ß fold class, exhibiting an open twisted ß-sheet core surrounded by α-helices. The asymmetric unit contains one AAA molecule and the monomeric form is functionally active. The core structure enclosing the signature sequence region, including the canonical Ser-cisSer-Lys catalytic triad, is conserved in all members of the Amidase Signature enzyme family. The structure of AAA in a complex with its ligand reveals a unique organization in the substrate-binding pocket. The binding pocket consists of two loops (loop1 and loop2) in the amidase signature sequence and one helix (α10) in the non-amidase signature sequence. We identified two residues (Tyr(136) and Thr(330)) that interact with the ligand via water molecules, and a hydrogen-bonding network that explains the catalytic affinity over various aryl acyl compounds. The optimum activity of AAA at pH > 10 suggests that the reaction mechanism employs Lys(84) as the catalytic base to polarize the Ser(187) nucleophile in the catalytic triad.
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Acetaminofén/química , Amidohidrolasas/química , Proteínas Bacterianas/química , Amidohidrolasas/genética , Secuencias de Aminoácidos , Proteínas Bacterianas/genética , Dominio Catalítico , Cristalografía por Rayos X , Escherichia coli/genética , Escherichia coli/metabolismo , Expresión Génica , Enlace de Hidrógeno , Ligandos , Datos de Secuencia Molecular , Unión Proteica , Estructura Secundaria de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Alineación de Secuencia , Especificidad por Sustrato , Agua/químicaRESUMEN
Despite recent progress in research on the Hippo signalling pathway, the structural information available in this area is extremely limited. Intriguingly, the homodimeric and heterodimeric interactions of mammalian sterile 20-like (MST) kinases through the so-called `SARAH' (SAV/RASSF/HPO) domains play a critical role in cellular homeostasis, dictating the fate of the cell regarding cell proliferation or apoptosis. To understand the mechanism of the heterodimerization of SARAH domains, the three-dimensional structures of an MST1-RASSF5 SARAH heterodimer and an MST2 SARAH homodimer were determined by X-ray crystallography and were analysed together with that previously determined for the MST1 SARAH homodimer. While the structure of the MST2 homodimer resembled that of the MST1 homodimer, the MST1-RASSF5 heterodimer showed distinct structural features. Firstly, the six N-terminal residues (Asp432-Lys437), which correspond to the short N-terminal 310-helix h1 kinked from the h2 helix in the MST1 homodimer, were disordered. Furthermore, the MST1 SARAH domain in the MST1-RASSF5 complex showed a longer helical structure (Ser438-Lys480) than that in the MST1 homodimer (Val441-Lys480). Moreover, extensive polar and nonpolar contacts in the MST1-RASSF5 SARAH domain were identified which strengthen the interactions in the heterodimer in comparison to the interactions in the homodimer. Denaturation experiments performed using urea also indicated that the MST-RASSF heterodimers are substantially more stable than the MST homodimers. These findings provide structural insights into the role of the MST1-RASSF5 SARAH domain in apoptosis signalling.
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Quinasas Quinasa Quinasa PAM/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Transducción de Señal , Secuencia de Aminoácidos , Cristalografía por Rayos X , Dimerización , Vía de Señalización Hippo , Humanos , Datos de Secuencia Molecular , Conformación Proteica , Homología de Secuencia de AminoácidoRESUMEN
BACKGROUND: The results of epidemiologic studies of the association between serum γ-glutamyltransferase (GGT) and brachial-ankle pulse wave velocity (baPWV) have been inconsistent. We examined the association between serum GGT and arterial stiffness in a general population of Korean adults. METHODS: The study population consisted of 6314 community-dwelling Koreans who participated in the baseline survey of the Namwon Study. We analyzed sex-specific association between serum GGT and arterial stiffness, as measured by baPWV. RESULTS: There was a significant progressive increase in age-adjusted mean baPWV across quartiles of GGT in both sexes. In fully adjusted analysis, as compared with the lowest quartile, the odds ratios (95% CI) for high baPWV (ie, sex-specific fifth quintile) were 1.51 (1.03-2.23), 1.82 (1.22-2.72), and 2.80 (1.79-4.40) among men (P-trend <0.001), and 1.11 (0.81-1.52), 1.29 (0.94-1.76), and 1.47 (1.04-2.08) among women (P-trend <0.001), for the second, third, and fourth quartiles of GGT, respectively. CONCLUSIONS: This population-based study examined the dose-response relationship between GGT and arterial stiffness as measured by baPWV in both sexes. The association between GGT and arterial stiffness was stronger among men. Additional longitudinal studies are needed to examine the relationship between GGT and arterial stiffness and clarify the mechanism underlying the association.
Asunto(s)
Rigidez Vascular/fisiología , gamma-Glutamiltransferasa/sangre , Anciano , Índice Tobillo Braquial , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Análisis de la Onda del Pulso , República de Corea/epidemiología , Distribución por SexoRESUMEN
BACKGROUND AND OBJECTIVES: Familial hypercholesterolemia (FH) increases the risk of premature cardiovascular disease through disrupted low-density lipoprotein cholesterol (LDL-C) metabolism. Although FH is a severe condition, it remains widely underdiagnosed, which can be attributed to barriers in genetic testing and a lack of awareness. This study aims to propose and evaluate a targeted screening program for FH in South Korea by integrating the General Health Screening Program (GHSP) with cascade genetic screening. METHODS: The study included individuals with LDL-C levels ≥190 mg/dL identified during the 2021 GHSP (primary participants). Data on demographics, lifestyle, medical history, and family history were collected through questionnaires. Targeted next-generation sequencing was used to identify pathogenic mutations in the PCSK9, APOB, LDLRAP1, and LDLR genes associated with FH. Pathogenic mutations found in primary participants were confirmed in their relatives (secondary participants) using Sanger sequencing. Participant characteristics were analyzed based on the presence of pathogenic mutations. RESULTS: Among 83 individuals with severe hypercholesterolemia identified through the GHSP, 7 primary participants (8.4%) carried pathogenic mutations in the LDLR and PCSK9 genes. In secondary participants, pathogenic mutations were identified in 61.1% of the relatives of 4 patients with pathogenic mutations. The prevalence of pathogenic mutations was significantly higher in primary participants compared to secondary participants. CONCLUSIONS: Integrating community resources with FH screening can enhance the early detection and treatment of FH. By utilizing GHSP data and adding genetic screening, the proposed model provides a strategy to reduce the cardiovascular risks associated with FH, supporting its wider adoption at the national level.