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1.
Cell Biol Int ; 47(7): 1259-1266, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36959746

RESUMO

Glutamate receptor, ionotropic, kainate 5 (GRIK5) is a member of glutamate receptors participating, and the kainate receptor family has been proved to regulate cell proliferation and transformation. Our study aimed at exploring the role of GRIK5 in colon tumor progression. Three hundred and ninety eight colon cancer patients in The Cancer Genome Atlas Program (TCGA) data set and 26 clinical colon cancer patients were included for GRIK5 expression and prognosis analysis. GRIK5 overexpressed HCT116 and CT26 cell lines were established for cell proliferation and Transwell assay. Western blot analysis and immunostaining assay was conducted to evaluate the activation of activation of cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA)/cell adhesion molecular 3 (CADM3) signaling in cell lines and tumor tissues. Subcutaneous CT26-bearing mice model was established to examine GRIK5-induced tumor growth and metastasis in vivo. Our study identified GRIK5 to be upregulated in patients with colon cancer, and higher GRIK5 levels correlated with the poor overall survival in patients. In vitro, GRIK5 overexpression markedly enhanced the proliferative properties and aggressive behaviors of colon cancer cells. Mechanistically, GRIK5 induced the activation of cAMP/PKA signaling, proceeded with augmented CADM3 expression, eventually resulting in sustained tumor growth. GRIK5 was a crucial scaffold in enabling colon cancer growth and metastasis, which offered a promising target for therapeutic manipulation of colon cancer.


Assuntos
Neoplasias do Colo , Ácido Caínico , Camundongos , Animais , Neoplasias do Colo/metabolismo , Transdução de Sinais/genética , AMP Cíclico/metabolismo , Receptores de Glutamato , Proliferação de Células , Linhagem Celular Tumoral
2.
Biotechnol Appl Biochem ; 64(1): 43-49, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26592736

RESUMO

Nesfatin-1 is a newly discovered satiety molecule expressed mainly in the hypothalamic nuclei. It suppresses both short-term and long-term appetite. Six synthetic deoxyoligonucleotides overlapped by PCR encoding nesfatin-1 were cloned into a pET28a vector after the hexa-histidine-tagged multiple cloning sites sequence with an enterokinase recognition site incorporated in-between. The recombinant plasmid was transformed into Escherichia coli strain Rosetta to express the fusion protein, which constituted 27% of the total cell proteins. After purified by Ni-sepharose affinity chromatography, the fusion protein was treated with enterokinase to release nesfatin-1. The nesfatin-1 sample was further purified with reverse-phase high performance liquid chromatography (HPLC), and its molecular weight was determined by mass spectrometry. The biological activities of recombinant nesfatin-1 were also assessed using in vivo animal models. The method described here promises to produce about 8 mg biologically active nesfatin-1 with homogeneity over 98% from 1-L shaking flask culture of E. coli, which can be considered as an easy and cost-effective way to synthesize nesfatin-1.


Assuntos
Proteínas de Ligação ao Cálcio , Proteínas de Ligação a DNA , Escherichia coli/química , Escherichia coli/metabolismo , Expressão Gênica , Proteínas do Tecido Nervoso , Animais , Proteínas de Ligação ao Cálcio/biossíntese , Proteínas de Ligação ao Cálcio/química , Proteínas de Ligação ao Cálcio/genética , Proteínas de Ligação ao Cálcio/isolamento & purificação , Proteínas de Ligação a DNA/biossíntese , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/isolamento & purificação , Escherichia coli/genética , Camundongos , Proteínas do Tecido Nervoso/biossíntese , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/isolamento & purificação , Nucleobindinas , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
3.
AJR Am J Roentgenol ; 207(4): 859-864, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27340876

RESUMO

OBJECTIVE: The purpose of this article is to construct classifier models using machine learning algorithms and to evaluate their diagnostic performances for differentiating malignant from benign thyroid nodules. MATERIALS AND METHODS: This study included 970 histopathologically proven thyroid nodules in 970 patients. Two radiologists retrospectively reviewed ultrasound images, and nodules were graded according to a five-tier sonographic scoring system. Statistically significant variables based on an experienced radiologist's observations were obtained with attribute optimization using fivefold cross-validation and applied as the input nodes to build models for predicting malignancy of nodules. The performances of the machine learning algorithms and radiologists were compared using ROC curve analysis. RESULTS: Diagnosis by the experienced radiologist achieved the highest predictive accuracy of 88.66% with a specificity of 85.33%, whereas the radial basis function (RBF)-neural network (NN) achieved the highest sensitivity of 92.31%. The AUC value for diagnosis by the experienced radiologist (AUC = 0.9135) was greater than those for diagnosis by the less experienced radiologist, the naïve Bayes classifier, the support vector machine, and the RBF-NN (AUC = 0.8492, 0.8811, 0.9033, and 0.9103, respectively; p < 0.05). CONCLUSION: The machine learning algorithms underperformed with respect to the experienced radiologist's readings used to construct them, and the RBF-NN outperformed the other machine learning algorithm models.

5.
BMC Cancer ; 15: 158, 2015 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-25896668

RESUMO

BACKGROUND: Although microRNAs offer great potential as cancer biomarkers, effective clinical dignostics and tumor maker have not been verified to diagnose with colorectal cancer (CRC). The purpose of our study is to systematically assess the expression of miRNAs in matched cancer and normal tissue samples to identify promising diagnostic microRNA (miRNA) biomarkers for CRC. METHODS: In our study, we examined by Real-Time PCR the expression levels of 96 mature miRNA in 32 CRC patients with differently expressed tumors versus normal colon tissues. Using enter and stepwise variable selection methods separately, conditional logistic regression was conducted to identify miRNAs associated with CRC. The classification performance of these indicators was assessed under the Fisher discriminant analysis. Receiver operating characteristic curve analyses were applied to obtain diagnostic utility of the differentially expressed miRNAs. RESULTS: In this study, we confirmed 11 overexpressed miRNAs with no less than twofold difference, and 85 downexpressed miRNAs with up to 0.5-fold difference in CRC from 96 aberrantly expressed miRNAs being identified by real-time PCR. Conditional logistic regression results confirmed that miRNA-378 and miRNA-145 expression profile was statistically significant. The error diagnosis rate of these two miRNAs are 0.194 and 0.113, separeately, showing by discriminant analysis. CONCLUSIONS: MiRNA-145 and miRNA-378* are potential biomarkers for early detection of CRC, which may help in diagnosing CRC in early period.


Assuntos
Biomarcadores Tumorais/biossíntese , Neoplasias Colorretais/genética , MicroRNAs/biossíntese , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/genética , Neoplasias Colorretais/patologia , Detecção Precoce de Câncer , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , MicroRNAs/genética , Pessoa de Meia-Idade , Estadiamento de Neoplasias
6.
Gels ; 9(2)2023 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-36826340

RESUMO

The undesirable inherent natural characteristics of wood, such as low mechanical strength, flammability, and hygroscopicity, limit its potential applications in the thermal insulation industry. Overcoming these disadvantages can greatly expand the application scope of wood. A new attempt at wood modification, the directional-freezing-assisted in situ sol-gel strategy, was used to obtain wood-silica composite aerogels with the unique multi-level ordered porous structure of wood. This method enables silica nanoparticles to successfully replace lignin and facilitates the formation of strong hydrogen bonds between the silica and cellulose molecules. This results in improved mechanical properties for the composite with a density similar to that of natural wood but a mechanical strength that can be up to five times greater. The thermal conductivity coefficient is also reduced to 0.032 W (m·K)-1 compared to 0.066 W (m·K)-1 for natural wood. This aerogel composite exhibits improved fire resistance and hygroscopicity, with a decomposition temperature increase of approximately 45 °C compared to natural wood. Additionally, the composite demonstrates self-extinguishing behavior, with the structure remaining intact after combustion, and thus enhanced fire resistance. Simultaneously, the enhanced aerogel composite hydrophobicity, with water contact angle of up to 120°, is beneficial to a prominent thermal insulation performance in a high-humidity environment. The successful synthesis of wood-based composite aerogels provides a new and innovative approach for the utilization of wood resources in the thermal insulation industry.

7.
Gels ; 9(6)2023 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-37367138

RESUMO

The use of energy-saving materials is an effective strategy for decreasing energy consumption and carbon emission. Wood is a type of biomass material with a natural hierarchical structure, which results in its high thermal insulation. It has been widely used in construction. However, developing wood-based materials without flammability and dimensional instability is still a challenge. Herein, we developed a wood/polyimide composite aerogel with a well-preserved hierarchical pore structure and dense hydrogen bonds inside, resulting in its excellent chemical compatibility and strong interfacial interactions between its two components. This novel wood-based composite was fabricated by removing most hemicellulose and lignin from natural wood, followed by the fast impregnation using an 'in situ gel' process. The introduction of polyimide into delignified wood substantially improved its mechanical properties, with the compression resistance being improved by over five times. Notably, the thermal conductivity coefficient of the developed composite was approximately half that of natural wood. Furthermore, the composite exhibited excellent fire-retardancy, hydrophobicity, thermal insulation, and mechanical properties. This study provides a novel method for wood modification, which not only aids interfacial compatibility between wood and polyimide but also retains the properties of the two components. The developed composite can effectively reduce energy consumption, making it promising for practical and complex thermal insulation applications.

8.
J Cancer Res Clin Oncol ; 149(11): 8699-8709, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37127827

RESUMO

PURPOSE: Prostate cancer (PCa) is one of the most common malignancies in men and one of the leading causes of cancer-related deaths; circulating tumor cells (CTC) are malignant cells that have broken off from original tumor or metastatic sites and extravasated into the blood vessels either naturally or maybe as a consequence of surgical procedures. This study aims to explore the feasibility of liquid biopsy technique to diagnose prostate cancer. METHOD: We constructed an assay platform integrating magnetic separation and fluorescence in situ hybridization (FISH) to effectively capture prostate cancer CTCs and evaluate the distribution between healthy volunteers and prostate cancer patients, respectively. RESULTS: There was a significant difference in the number of CTCs between the healthy population and prostate cancer patients (P < 0.001). The results of the study showed that the CTCs capture identification system has good sensitivity and specificity in identifying prostate cancer patients. CONCLUSION: The CTCs test allows us to accurately identify patients who are at high risk for prostate cancer, allowing for early intervention and treating patients effectively.


Assuntos
Células Neoplásicas Circulantes , Neoplasias da Próstata , Humanos , Masculino , Molécula de Adesão da Célula Epitelial/genética , Estudos de Viabilidade , Vimentina , Hibridização in Situ Fluorescente , Biomarcadores Tumorais/genética , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/genética , Células Neoplásicas Circulantes/patologia
9.
Front Oncol ; 13: 1175518, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37876972

RESUMO

Extraosseous osteosarcoma is a rare malignant tumor, most commonly occurring in the thigh, upper limbs, and retroperitoneum. However, there are only a few reported cases of renal osteosarcoma. Herein, we present the case of a 54-year-old woman with malignant extraosseous osteosarcoma of the left kidney. CT and MR imaging revealed a soft tissue mass originating from the left kidney.

10.
Front Med (Lausanne) ; 10: 1239053, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37809339

RESUMO

We report displacement of the distal end of a ureteral double-J stent into the contralateral ureter after percutaneous nephrolithotripsy (PCNL) in a 71-year-old man with a history of left kidney stones. Postoperative computed tomography imaging showed that the distal end of the left ureteral double-J stent was displaced into the right ureter, which resulted in persistent right renal colic when the nephrostomy tube was clipped and continuous urine leakage from the nephrostomy opening after the nephrostomy tube was removed. After the cystoscopic adjustment of the ureteral stent, the patient recovered uneventfully and was discharged home the next day.

11.
Front Med (Lausanne) ; 10: 1202486, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37601775

RESUMO

Obstructive: To develop and validate radiomics and machine learning models for identifying encrusted stents and compare their recognition performance with multiple metrics. Methods: A total of 354 patients with ureteral stent placement were enrolled from two medical institutions and divided into the training cohort (n = 189), internal validation cohort (n = 81) and external validation cohort (n = 84). Based on features selected by Wilcoxon test, Spearman Correlation Analysis and least absolute shrinkage and selection operator (LASSO) regression algorithm, six machine learning models based on radiomics features were established with six classifiers (LR, DT, SVM, RF, XGBoost, KNN). After comparison with those models, the most robust model was selected. Considering its feature importance as radscore, the combined model and a nomogram were constructed by incorporating indwelling time. Accuracy, sensitivity, specificity, area under the curve (AUC), decision curve analysis (DCA) and calibration curve were used to evaluate the recognition performance of models. Results: 1,409 radiomics features were extracted from 641 volumes of interest (VOIs) and 20 significant radiomics features were selected. Considering the superior performance (AUC 0.810, 95%CI, 0.722-0.888) in the external validation cohort, feature importance of XGBoost was used as a radscore, constructing a combined model and a nomogram with indwelling time. The accuracy, sensitivity, specificity and AUC of the combined model were 98, 100, 97.3% and 0.999 for the training cohort, 83.3, 80, 84.5% and 0.867 for the internal cohort and 78.2, 76.3, 78.8% and 0.820 for the external cohort, respectively. DCA indicates the favorable clinical utility of models. Conclusion: Machine learning model based on radiomics features enables to identify ureteral stent encrustation with high accuracy.

12.
Synth Syst Biotechnol ; 8(3): 378-385, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37692204

RESUMO

Owing to the feature of strong α-glucosidase inhibitory activity, 1-deoxynojirimycin (1-DNJ) has broad application prospects in areas of functional food, biomedicine, etc., and this research wants to construct an efficient strain for 1-DNJ production, basing on Bacillus amyloliquefaciens HZ-12. Firstly, using the temperature-sensitive shuttle plasmid T2 (2)-Ori, gene ptsG in phosphotransferase system (PTS) was weakened by homologous recombination, and non-PTS pathway was strengthened by deleting its repressor gene iolR, and 1-DNJ yield of resultant strain HZ-S2 was increased by 4.27-fold, reached 110.72 mg/L. Then, to increase precursor fructose-6-phosphate (F-6-P) supply, phosphofructokinase was weaken, fructose phosphatase GlpX and 6-phosphate glucose isomerase Pgi were strengthened by promoter replacement, moreover, regulator gene nanR was deleted, 1-DNJ yield was further increased to 267.37 mg/L by 2.41-fold. Subsequently, promoter of 1-DNJ synthetase cluster was optimized, as well as 5'-UTRs of downstream genes in synthetase cluster, and 1-DNJ produced by the final strain reached 478.62 mg/L. Last but not the least, 1-DNJ yield of 1632.50 mg/L was attained in 3 L fermenter, which was the highest yield of 1-DNJ reported to date. Taken together, our results demonstrated that metabolic engineering was an effective strategy for 1-DNJ synthesis, this research laid a foundation for industrialization of functional food and drugs based on 1-DNJ.

13.
Front Oncol ; 13: 1260706, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38023229

RESUMO

In this report, we present a case study of a 64-year-old female who was diagnosed with gastrointestinal stromal tumors (GISTs) and subsequently developed liver metastases despite undergoing radical resection. Next-generation sequencing (NGS) assays indicated that the tumor lacked KIT/PDGFRA/SDH/RAS-P (RAS pathways, RAS-P) mutations, thereby classifying this patient as quadruple WT GIST (qGIST). Treatment with imatinib was initiated, and after 2.5 months, recurrence of the tumor and multiple metastases around the surgical site were observed. Consequently, the patient was switched to sunitinib treatment and responded well. Although she responded well to sunitinib, the patient died of tumor dissemination within 4 months. This case study highlights the potential efficacy of imatinib and the VEGFR-TKI sunitinib in treating qGIST patients harboring a TP53 missense mutation.

14.
Am J Rhinol Allergy ; 36(6): 708-718, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35695194

RESUMO

Sinonasal squamous cell carcinoma (SNSCC) is one of the least frequent carcinomas in the head and neck and accounts for 60% to 75% of sinonasal malignancies. The role of long non-coding RNAs (lncRNAs) in cancer development has drawn great attention over the years. The current study intended to assess the role and specific mechanism of lncRNA double homeobox A pseudogene 8 (DUXAP8) in SNSCC. Quantitative real-time PCR (qRT-PCR) analysis was implemented to assess the expression level of DUXAP8, microRNA-584-5p (miR-584-5p), and fibronectin type III domain containing 3B (FNDC3B). Proliferation assays included colony formation assay, Cell Counting Kit-8 (CCK-8) assay, and 5-ethynyl-2'-deoxyuridine (EdU) assay. Transwell assays were implemented to monitor cell migration and invasion. Cell apoptosis was evaluated via terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling (TUNEL) and JC-1 experiments. Mechanism experiments included RNA pull-down assay, RNA binding protein immunoprecipitation (RIP) assay, and luciferase reporter assay. DUXAP8 is overexpressed in SNSCC cells. Functionally, DUXAP8 silencing suppresses the malignant progression of SNSCC. Furthermore, DUXAP8 up-regulates the expression of FNDC3B via sponging miR-584-5p. Rescue experiments demonstrated that DUXAP8 mediates the progression of SNSCC via up-regulating FNDC3B expression. In conclusion, DUXAP8 acts as an oncogene in SNSCC, which may be a new molecular marker for SNSCC.


Assuntos
Carcinoma de Células Escamosas , MicroRNAs , RNA Longo não Codificante , Carcinoma de Células Escamosas/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , DNA Nucleotidilexotransferase/genética , DNA Nucleotidilexotransferase/metabolismo , Fibronectinas/metabolismo , Regulação Neoplásica da Expressão Gênica , Genes Homeobox , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Oncogenes , Pseudogenes , RNA Longo não Codificante/genética
15.
J Cardiothorac Surg ; 16(1): 87, 2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33858482

RESUMO

BACKGROUND: The identification of targeted intersegmental planes and resection with adequate surgical margins are among the crucial steps in anatomical pulmonary segmentectomy, and technical improvements are still needed. CASE PRESENTATION: We reported three cases of intersegmental plane identification using highly selective independent segmental ventilation during segmentectomy. All cases required cooperation with an anesthesiologist who was able to perform segmental ventilation and double confirmation of segmental bronchus branches by the surgeon. The surgical procedure provides a direct visualization of spare segment inflation and saves time in deflation over the conventional residual segment inflation method. CONCLUSIONS: Highly selective independent segmental ventilation could be considered a suitable option for pulmonary intersegmental plane identification and could be universally used for lung segmentectomy.


Assuntos
Anestesia em Procedimentos Cardíacos/métodos , Neoplasias Pulmonares/cirurgia , Pulmão/cirurgia , Pneumonectomia/métodos , Respiração Artificial/métodos , Cirurgia Torácica Vídeoassistida/métodos , Idoso , Humanos , Cuidados Intraoperatórios , Intubação Intratraqueal/métodos , Pulmão/anatomia & histologia , Pulmão/diagnóstico por imagem , Neoplasias Pulmonares/diagnóstico por imagem , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios X
16.
Front Genet ; 12: 755629, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35154239

RESUMO

Background: Bowel cancer is the third-most common cancer and the second leading cause of cancer-related death worldwide. Bowel cancer has a substantial hereditary component; however, additional hereditary risk factors involved in bowel cancer pathogenesis have not been systematically defined. Materials and Methods: A total of 573 patients with bowel cancer were enrolled in the present study, of whom 93.72% had colorectal cancer (CRC). Germline mutations were integrated with somatic mutation information via utilizing target next-generation sequencing. Results: Pathogenic/Likely Pathogenic (P/LP) germline alterations were identified in 47 (8.2%) patients with bowel cancer and the ratio of the number of these patients with family history was significantly higher in the P/LP group than that noted in the non-pathogenic (Non-P) group. Certain rare germline alterations were noted, such as those noted in the following genes: FANCD2, CDH1, and FLCN. A total of 32 patients (68.1%) had germline alterations in the DNA-damage repair (DDR) genes and homologous recombination (HR) accounted for the highest proportion of this subgroup. By comparing 573 patients with bowel cancer with reference controls (China_MAPs database), significant associations (p < 0.01) were observed between the incidence of bowel cancer and the presence of mutations in APC, ATM, MLH1, FANCD2, MSH3, MSH6, PMS1, and RAD51D. Somatic gene differential analysis revealed a marked difference in 18 genes and a significant difference was also noted in tumor mutation burden (TMB) between germline mutation carriers and non-germline mutation subjects (p < 0.001). In addition, TMB in DDR mutation groups indicated a dramatic difference compared with the non-DDR mutation group (p < 0.01). However, no statistically significant differences in TMB were noted among detailed DDR pathways for patients with bowel cancer, irrespective of the presence of germline mutations. Moreover, a significantly higher level (p < 0.0001) of mutation count was observed in the DDR group from The Cancer Genome Atlas (TCGA) database and the DDR and non-DDR alteration groups displayed various immune profiles. Conclusion: Chinese patients with bowel cancer exhibited a distinct spectrum of germline variants, with distinct molecular characteristics such as TMB and DDR. Furthermore, the information on somatic mutations obtained from TCGA database indicated that a deeper understanding of the interactions among DDR and immune cells would be useful to further investigate the role of DDR in bowel cancer.

17.
Polymers (Basel) ; 12(3)2020 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-32111054

RESUMO

Hydroxyethyl cellulose (HEC) was introduced to activate the surface of polyurethane (PU) sponge to successfully prepare a hydrophobic ternary composite PU/HEC/SiO2. The hydrophobic layer of the composite was realized by in-situ polymerization of methyltriethoxysilane (MTES) onto the surface of PU sponge. The formation of a stable hydrophobic SiO2 layer solved successfully the problem of ease of SiO2 particles shedding from the composite. Moreover, the amphiphilic molecules produced by the hydrolysis of MTES monomers facilitated the preparation of hydrophobic materials by aqueous dispersion polymerization. Aqueous synthesis made the reaction process environmentally-friendly and pollution-free. The as-prepared composite PU/HEC/SiO2 not only retains high porosity and low density of the PU sponge, but also considerably reduced the surface free energy and increased the surface roughness of the PU sponge. Therefore, outstanding hydrophobicity and high porosity endow the composite with excellent oil removal capability as a high-efficiency absorbent. Moreover, the hydrophobic composite that had absorbed oil could be regenerated easily by squeezing and recycling.

18.
Protein Expr Purif ; 65(2): 238-43, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19152836

RESUMO

Aprotinin is a Kunitz-type inhibitor with a relatively broad specificity. It has been shown to be clinically useful for the management of hemorrhagic complications. In this report, small ubiquitin-related modifier (SUMO) linked with a hexa-histidine tag was used as a fusion partner for the production of recombinant aprotinin and a human aprotinin analogue (cloned form human cDNA library). Both fusion proteins were overexpressed mainly as inclusion bodies in Escherichia coli and accounted for approximately 28% of the total cell proteins. After purification by Ni-Sepharose affinity chromatography and renaturation, the fusion proteins were cleaved with SUMO protease 1. Aprotinin and its analogue were separated from the fusion partner by the subtractive chromatography using Ni-Sepharose and then further purified with CM-cellulose. Kinetic studies demonstrated that the amidolytic activity of plasmin was competitively inhibited by recombinant aprotinin with a K(i) of 8.6+/-2.4 nM, which was similar to the K(i) (7.5+/-2.7 nM) of natural aprotinin. The K(i) of human aprotinin analogue was 22.7+/-6.5 nM. The expression strategy described in this study allows convenient high yield and easy purification of small recombinant protease inhibitors with complete native sequences.


Assuntos
Aprotinina/isolamento & purificação , Aprotinina/farmacologia , Fibrinolisina/antagonistas & inibidores , Proteínas Recombinantes de Fusão/isolamento & purificação , Proteínas Recombinantes de Fusão/farmacologia , Aprotinina/biossíntese , Aprotinina/química , Cromatografia de Afinidade , Cromatografia Líquida de Alta Pressão , Escherichia coli/genética , Escherichia coli/metabolismo , Biblioteca Gênica , Humanos , Cinética , Reação em Cadeia da Polimerase , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/química , Proteína SUMO-1/metabolismo , Solubilidade
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