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1.
Chronobiol Int ; 41(9): 1239-1247, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39164845

RESUMO

Our study, conducted between April 2022 and January 2024, was aimed at clarifying components of the rest-activity rhythm (RAR) involved in improvement of social frailty state before or after a 3-month multi-component exercise intervention in the elderly. Participants were recruited from the general population in Akita prefecture, Japan. We administered a four-item social frailty screening questionnaire to classify the severity of social frailty in each participant before and after the 3-month intervention. The RAR parameters were measured on an Actiwatch Spectrum Plus device worn by the subjects for 7 continuous days. As the final sample, 65 participants classified into the improved/maintained group (n = 36) or the deteriorated group (n = 29) according to the change in the social frailty classification after the intervention were included in the analysis. The results of a binomial logistic regression analysis showed significantly higher values of interdaily stability (IS) and usual walking speed at the post-test after the intervention. Based on our findings, we propose that stability of the rest-activity rhythm related to synchronization with external stimuli (such as social effect and physical activity) might have clinical impact on improvement of social frailty state in elderly community-dwellers.


Assuntos
Idoso Fragilizado , Fragilidade , Descanso , Caminhada , Humanos , Idoso , Masculino , Feminino , Caminhada/fisiologia , Fragilidade/fisiopatologia , Idoso de 80 Anos ou mais , Descanso/fisiologia , Japão , Exercício Físico/fisiologia , Inquéritos e Questionários , Ritmo Circadiano/fisiologia
2.
Cancer Diagn Progn ; 4(3): 370-378, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38707725

RESUMO

Background/Aim: Nuclear protein in testis (NUT) carcinoma is extremely rare, occurs in the midline of the body, progresses rapidly and is refractory to treatment; most patients die within a year. Here, we describe a case of maxillary sinus NUT carcinoma presenting with epistaxis and nasal obstruction that was treated as a standard head and neck carcinoma. Case Report: The patient was a 41-year-old male with a left buccal swelling; the diagnosis was made of primary NUT carcinoma of the left maxillary sinus and bone metastasis in the cervical spine. After induction chemotherapy with docetaxel plus cisplatin and 5-fluorouracil, the tumor decreased in size, and the patient was further treated with cisplatin and radiation therapy. One month after that, the tumor remained small, however, lung metastasis was observed. Therefore, nivolumab was administered. Cetuximab and paclitaxel were administered after the lung metastasis worsened, but the patient developed progressive disease and died 11 months after diagnosis. Conclusion: Effective treatments for NUT carcinoma have not yet been established. However, early testing to establish the diagnosis may provide useful insights to guide clinical decisions to improve patient outcomes.

3.
SAGE Open Med Case Rep ; 12: 2050313X241253462, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38764912

RESUMO

Malignant otitis externa (skull base osteomyelitis) can be fatal and long-term antibiotic therapy is recommended. Despite being potentially fatal, this infection causes minor changes in inflammatory biomarkers (white blood cell count and C-reactive protein levels) upon blood testing. Computed tomography and magnetic resonance imaging changes persist over a long period. Therefore, it is difficult to determine the optimal time for the discontinuation of antibiotics. We present a 77-year-old male whose medical history included type 2 diabetes mellitus who suffered from chronic otitis media with Pseudomonas aeruginosa infection. His condition did not improve with proper treatment, and imaging revealed malignant otitis media. Intravenous cefepime treatment was administered. Antibiotic treatment was de-escalated to oral levofloxacin treatment after Gallium-67 scintigraphy showed less accumulation after 6 weeks of Cefepime administration; accumulation almost disappeared after 1 year. In this report, we describe the usefulness of gallium scintigraphy in the evaluation of malignant otitis externa.

4.
In Vivo ; 38(3): 1454-1458, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38688641

RESUMO

BACKGROUND/AIM: First bite syndrome (FBS) is a symptom of severe pain at the beginning of a meal that lessens as the meal progresses. It is a common postoperative complication of parapharyngeal space tumors and is rarely reported as the first symptom of parotid carcinoma. The parapharyngeal space is considered a difficult area for approach; hence, preoperative histopathology is often challenging. However, there are hardly any reports on the approach of performing biopsies under computerized tomography (CT) guidance. CASE REPORT: A 28-year-old woman presented to our hospital with the chief complaint of pain in the left parotid region since the past year. Contrast-enhanced magnetic resonance imaging of the parotid gland revealed a 10-mm high-signal area on T2-weighted images extending from the deep lobe of the left parotid gland to the parapharyngeal space, which could not be visualized on ultrasound. She was suspected to have a malignant tumor because of the presence of a parotid tumor with FBS. Therefore, she underwent CT-guided fine-needle aspiration cytology (FNAC) and was diagnosed with adenoid cystic carcinoma. The patient underwent left parotid tumor resection and left cervical dissection, and her pain during feeding improved postoperatively. CONCLUSION: In a patient with parotid tumor extending into the parapharyngeal space with FBS as the initial symptom, CT-guided FNAC was successfully used to diagnose parotid carcinoma. Symptoms of pain, including FBS, should be considered in cases of malignancy. CT-guided FNAC is effective for lesions that cannot be visualized by ultrasound, such as those in the parapharyngeal space.


Assuntos
Biópsia Guiada por Imagem , Neoplasias Parotídeas , Tomografia Computadorizada por Raios X , Adulto , Feminino , Humanos , Biópsia por Agulha Fina , Biópsia Guiada por Imagem/métodos , Imageamento por Ressonância Magnética/métodos , Glândula Parótida/patologia , Glândula Parótida/diagnóstico por imagem , Neoplasias Parotídeas/patologia , Neoplasias Parotídeas/diagnóstico , Neoplasias Parotídeas/diagnóstico por imagem , Neoplasias Parotídeas/cirurgia
5.
J Poult Sci ; 61: 2024011, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38681190

RESUMO

Collagen content is an important parameter affecting meat consistency. Sex differences in collagen were therefore studied in mature and juvenile Shamo chickens. The pectoral (PT), lateral iliotibial (ITL), medial part of puboischiofemoral (PIF), and lateral part of gastrocnemius (GCL) muscles were weighed, and their COL1A1 expression levels and total collagen content were analyzed. Body and muscle weights were significantly higher in males than in females of all ages. Muscle/body weight ratios were also higher in mature males than in females, but this difference was not observed in juveniles. In mature chickens, COL1A1 expression was higher in the PIF and GCL muscles; this was not the case in juvenile chicken muscles. Sex differences in collagen content were observed only in the ITLs of mature chickens. A positive correlation between muscle weight and intramuscular collagen content was found for PT and GCL, but not for ITL and PIF, muscles. These results suggest that the sex difference in intramuscular collagen content only occurs in specific muscles and that COL1A1 expression is not necessarily related to collagen content in mature chickens. Factors that determine the intramuscular collagen content likely differ by muscle type.

6.
J Pharm Health Care Sci ; 9(1): 51, 2023 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-38082333

RESUMO

BACKGROUND: Prescribing with high levels of medical appropriateness and patient satisfaction improves adherence. However, its appropriateness does not always match patient preference. Deprescription is important for ensuring the safety of medication therapy, but is not straightforward. Although successful deprescribing requires knowledge of patients' thoughts on their prescriptions and factors that influence their acceptance of deprescribing, few comprehensive studies have been conducted on this topic. The aim of this study was to identify factors that influence patients' attitudes toward deprescribing and obtain hints on how to achieve higher patient satisfaction and prescribing adequacy. METHODS: A questionnaire was administered to hospitalized patients and a logistic regression analysis was conducted to examine factors that influence their attitude toward deprescribing. Individual factors affecting patients' thoughts and wishes regarding prescribing were extracted and analysed in detail. RESULTS: The analysis included 106 patients, of whom 40 (37.7%) wished deprescribing. Logistic regression analysis showed that "Age", "Wish to reduce the number and types of medications", "Satisfaction", "Concerns about side effects", and "Wish not to have certain medications changed" were factors influencing attitudes toward deprescribing. The results suggested that the factors were influenced by patients' perceptions and individual patient backgrounds. There was a gap between willingness to reduce medication and to change their medications. Seventy-eight percent of all respondents indicated that they would like to reduce the number and type of pills they take if possible. However, only 44.6% of these patients indicated that they would actually like to change their medication. CONCLUSIONS: This study is the only one to comprehensively investigate prescription content, patient background, and patients' thoughts on factors influencing attitudes toward deprescribing. This study revealed five factors that can influence inclination toward deprescribing. In addition, the results suggest that patients want to be able to feel well with fewer medications if possible. This information may be useful in determining prescriptions that have high validity and patient satisfaction. Further research is needed on the gap between willingness to reduce medications and to change medications.

7.
J Poult Sci ; 60: 2023026, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37900358

RESUMO

Collagen content and collagen fiber architecture in the skin of Shamo chickens were compared between sexes and body parts. Cervical, thoracic, dorsal, femoral, and crural skin samples were collected and their collagen content was analyzed. Collagen fiber specimens were prepared for scanning electron microscopy using the cell maceration method with a NaOH solution. Sex differences in collagen content were only observed in the femoral skin of mature chickens, but not in 10-week-old chicks. The difference in collagen content between body parts was obvious; femoral and crural skin had higher collagen content than those of other parts in both sexes. Scanning electron microscopy indicated that the collagen fiber architecture was quite different between the superficial and deep layers in the dermis, with the former consisting of loosely tangled band-like collagen fibers, and the latter composed of thick and dense layers of collagen bundles in a parallel arrangement. The width of collagen fibers in the superficial layer of the dermis differed between sexes in the dorsal, femoral, and crural skin. From these results, it is likely that the difference in collagen content in the femoral skin is not due to sex hormones but other factors, such as mechanical stimulation in daily activity. Additionally, collagen fiber width in the superficial layer is likely related to the difference in collagen content between sexes and between body parts.

8.
J Poult Sci ; 59(2): 162-167, 2022 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-35528379

RESUMO

Skin thickness and strength differ between male and female chickens. This study aimed to clarify the effects of estradiol on the expression of estrogen receptors and collagen mRNA in chicken skin. Estradiol was administered to male chicks for 3 weeks, then cryosections of skin collected from the cervical, thoracic, dorsal, and pelvic limb regions were stained with hematoxylin and eosin, and dermal thickness was measured. Estrogen receptor and collagen mRNA expression was assessed using real-time RT-PCR, and collagen contents were determined. Estradiol did not alter dermal thickness or the collagen content of the skin from any tested region. Among the estrogen receptors, significantly more ESR1 mRNA was expressed in the thoracic skin of chicks administered with estradiol compared with vehicle (control), and in the thoracic skin compared with skin from other regions within each group. Estradiol did not affect ESR2, GPER, and COL1A1 mRNA expression. These results suggested that estradiol stimulates ESR1 expression in thoracic skin, but does not affect collagen synthesis in skin from any other region of male chicks.

9.
Sci Rep ; 11(1): 1715, 2021 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-33462322

RESUMO

To evaluate the impact of pharmacotherapy on efficacy and safety by providing laboratory data information linked to medicines on outpatient prescriptions from the hospital to the community pharmacy. Beginning on October 28, 2014, standardized laboratory data and drug-linking laboratory data were included with outpatient prescriptions at our hospital. We have created a database of drug-linking laboratory data for all drugs that can be prescribed in Japan. We counted the number of prescription inquiries related to laboratory data from community pharmacies, including those leading to prescription changes. Before laboratory data were listed on outpatient prescriptions, 4 prescription inquiries from community pharmacies per year were related to laboratory data. After our hospital started to list laboratory data, this number rose to 643, 576, 563, and 847 in the first, second, third, and fourth year (P < .05). Of these, 132, 143, 152, and 224 inquiries resulted in prescription changes. Listing laboratory data on outpatient prescriptions avoided 153 contraindications and 84 exacerbations of adverse drug reactions in four years by a prescription inquiry that had never been done before. The efficacy and safety of pharmacotherapy can be improved by listing relevant laboratory data on outpatient prescriptions.

10.
Cancer Sci ; 112(2): 563-574, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33211385

RESUMO

Copy number alterations detected by comparative genomic hybridization (CGH) can lead to the identification of novel cancer-related genes. We analyzed chromosomal aberrations in a set of 100 human primary colorectal cancers (CRCs) using CGH and found a solute carrier (SLC) 7A1 gene, which encodes cationic amino acid transporter 1 (CAT1) with 14 putative transmembrane domains, in a chromosome region (13q12.3) with a high frequency of gene amplifications. SLC7A1/CAT1 is a transporter responsible for the uptake of cationic amino acids (arginine, lysine, and ornithine) essential for cellular growth. Microarray and PCR analyses have revealed that mRNA transcribed from CAT1 is overexpressed in more than 70% of human CRC samples, and RNA interference-mediated knockdown of CAT1 inhibited the cell growth of CRCs. Rats were immunized with rat hepatoma cells expressing CAT1 tagged with green fluorescent protein (GFP), and rat splenocytes were fused with mouse myeloma cells. Five rat monoclonal antibodies (mAbs) (CA1 ~ CA5) reacting with HEK293 cells expressing CAT1-GFP in a GFP expression-dependent manner were selected from established hybridoma clones. Novel anti-CAT1 mAbs selectively reacted with human CRC tumor tissues compared with adjacent normal tissues according to immuno-histochemical staining and bound strongly to numerous human cancer cell lines by flow cytometry. Anti-CAT1 mAbs exhibited internalization activity, antibody-dependent cellular cytotoxicity, and migration inhibition activity against CRC cell lines. Furthermore, CA2 inhibited the in vivo growth of human HT29 and SW-C4 CRC tumors in nude mice. This study suggested CAT1 to be a promising target for mAb therapy against CRCs.


Assuntos
Anticorpos Monoclonais/farmacologia , Antineoplásicos Imunológicos/farmacologia , Transportador 1 de Aminoácidos Catiônicos/antagonistas & inibidores , Neoplasias Colorretais/genética , Animais , Transportador 1 de Aminoácidos Catiônicos/genética , Linhagem Celular Tumoral , Amplificação de Genes , Xenoenxertos , Humanos , Camundongos , Camundongos Nus , Ratos
11.
J Pharm Health Care Sci ; 6(1): 27, 2020 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-33292744

RESUMO

BACKGROUND: Generic drugs are heavily promoted in Japan. The aim of this retrospective single-center study was to clarify whether the frequency and reason that patients request a switch from a generic drug to the original drug differ according to therapeutic category and dosage form. METHODS: This study was performed at Chiba University Hospital. Prescription inquiries about 121 generic drugs from community pharmacies over a 3-year period (from July 2014 to June 2017) were analyzed. RESULTS: Approximately 30% of the requests were related to the efficacy, safety, and comfort of the generic drug. The most cited motive was "patient's desire with no reason given" at 44.5%. According to multiple logistic regression analysis, therapeutic categories and dosage forms were associated with the requests. The median request frequency differed according to therapeutic category and dosage form. The frequency was highest for "agents affecting the central nervous system" and "tablets and capsules", respectively. Among the therapeutic categories, "agents affecting the central nervous system" had the highest median number of requests related to "decreased effectiveness"; "cardiovascular agents" had the highest median number of requests related to "physician's instruction"; and "agents for the epidermis" had the highest median number of requests related to "uncomfortable to use". Among dosage forms, the odds ratio for patients' original drug request for "liniment and patch" was about 1.5 times that for "tablets and capsules". "Liniment and patch" had the highest median frequency of requests related to "decreased effectiveness", "uncomfortable to use", and "patient's desire with no reason given". CONCLUSIONS: The request frequency and reason differed according to therapeutic category and dosage form. Pharmacists should advise each patient properly about the choice and switching of drug brands, taking into account the therapeutic category and dosage form, especially liniments and patches.

12.
Artigo em Inglês | MEDLINE | ID: mdl-31497309

RESUMO

BACKGROUND: There is a lack of evidence that multidrug use triggers adverse events. Therefore, the main purpose of this study was to clarify the relationship between the total number of drugs and number of high-risk prescriptions administered to Japanese elderly patients. METHODS: Using hospital electronic medical records (EMR), we evaluated the prescriptions of outpatients aged 65 years or older. We defined prescriptions of potentially inappropriate medications (PIMs) and overlapping prescription of drugs with the same mechanism of action (DSAs) as high-risk prescriptions. We analyzed the relationship among total number of drugs and high-risk prescriptions. In addition, we performed a secondary research to determine whether the hospitalization rate and concomitant medication contents differ depending on the high-risk prescriptions. RESULTS: Data for 13,630 outpatients were analyzed. A significant positive correlation between the numbers of total drugs and PIMs was found. The prescription frequency of individual PIMs rose as the total number of prescription drugs increased. The odds ratio (OR) of overlapping DSAs was significantly higher in patients using 5 or more drugs. In addition, there were significantly more prescriptions of laxatives among patients with overlapping prescriptions of anticholinergic drugs. The use of almost all PIMs was not an independent risk factor for hospitalization; instead, the number of PIMs was an independent risk factor for hospitalization [OR 1.18 (95% CI, 1.12-1.26)]. CONCLUSIONS: The number of PIMs and overlapping DSAs were high in patients receiving multidrug treatment. To avoid adverse events and hospitalization, it might be useful to review prescriptions and consider the number of PIMs and overlapping DSAs.

13.
Sci Rep ; 6: 30013, 2016 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-27418197

RESUMO

Cardiovascular complications are the leading cause of death in autosomal dominant polycystic kidney disease (ADPKD), and intracranial aneurysm (ICA) causing subarachnoid hemorrhage is among the most serious complications. The diagnostic and therapeutic strategies for ICAs in ADPKD have not been fully established. We here generated induced pluripotent stem cells (iPSCs) from seven ADPKD patients, including four with ICAs. The vascular cells differentiated from ADPKD-iPSCs showed altered Ca(2+) entry and gene expression profiles compared with those of iPSCs from non-ADPKD subjects. We found that the expression level of a metalloenzyme gene, matrix metalloproteinase (MMP) 1, was specifically elevated in iPSC-derived endothelia from ADPKD patients with ICAs. Furthermore, we confirmed the correlation between the serum MMP1 levels and the development of ICAs in 354 ADPKD patients, indicating that high serum MMP1 levels may be a novel risk factor. These results suggest that cellular disease models with ADPKD-specific iPSCs can be used to study the disease mechanisms and to identify novel disease-related molecules or risk factors.


Assuntos
Células-Tronco Pluripotentes Induzidas/metabolismo , Aneurisma Intracraniano/patologia , Metaloproteinase 1 da Matriz/sangue , Rim Policístico Autossômico Dominante/patologia , Hemorragia Subaracnóidea/patologia , Idoso , Animais , Biomarcadores/sangue , Diferenciação Celular , Células Cultivadas , Metilação de DNA/genética , Feminino , Humanos , Aneurisma Intracraniano/sangue , Masculino , Metaloproteinase 1 da Matriz/biossíntese , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Pessoa de Meia-Idade , Rim Policístico Autossômico Dominante/mortalidade , Fatores de Risco , Canais de Cátion TRPP/genética
14.
Biochem Biophys Res Commun ; 448(2): 175-81, 2014 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-24780397

RESUMO

INTRODUCTION: Carnitine palmitoyltransferase II (CPT II) deficiency is an inherited disorder involving ß-oxidation of long-chain fatty acids (FAO), which leads to rhabdomyolysis and subsequent acute renal failure. The detailed mechanisms of disease pathogenesis remain unknown; however, the availability of relevant human cell types for investigation, such as skeletal muscle cells, is limited, and the development of novel disease models is required. METHODS: We generated human induced pluripotent stem cells (hiPSCs) from skin fibroblasts of a Japanese patient with CPT II deficiency. Mature myocytes were differentiated from the patient-derived hiPSCs by introducing myogenic differentiation 1 (MYOD1), the master transcriptional regulator of myocyte differentiation. Using an in vitro acylcarnitine profiling assay, we investigated the effects of a hypolipidemic drug, bezafibrate, and heat stress on mitochondrial FAO in CPT II-deficient myocytes and controls. RESULTS: CPT II-deficient myocytes accumulated more palmitoylcarnitine (C16) than did control myocytes. Heat stress, induced by incubation at 38°C, leads to a robust increase of C16 in CPT II-deficient myocytes, but not in controls. Bezafibrate reduced the amount of C16 in control and CPT II-deficient myocytes. DISCUSSION: In this study, we induced differentiation of CPT II-deficient hiPSCs into mature myocytes in a highly efficient and reproducible manner and recapitulated some aspects of the disease phenotypes of CPT II deficiency in the myocyte disease models. This approach addresses the challenges of modeling the abnormality of FAO in CPT II deficiency using iPSC technology and has the potential to revolutionize translational research in this field.


Assuntos
Carnitina O-Palmitoiltransferase/deficiência , Erros Inatos do Metabolismo/metabolismo , Erros Inatos do Metabolismo/patologia , Células Musculares/patologia , Células-Tronco Pluripotentes/patologia , Bezafibrato/farmacologia , Carnitina/análogos & derivados , Carnitina/metabolismo , Carnitina O-Palmitoiltransferase/genética , Carnitina O-Palmitoiltransferase/metabolismo , Diferenciação Celular , Células Cultivadas , Fibroblastos/patologia , Regulação da Expressão Gênica , Humanos , Masculino , Células Musculares/efeitos dos fármacos , Células Musculares/metabolismo , Palmitoilcarnitina/metabolismo , Células-Tronco Pluripotentes/metabolismo , Adulto Jovem
15.
Nat Commun ; 4: 1367, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23340407

RESUMO

A method for stimulating the differentiation of human pluripotent stem cells into kidney lineages remains to be developed. Most cells in kidney are derived from an embryonic germ layer known as intermediate mesoderm. Here we show the establishment of an efficient system of homologous recombination in human pluripotent stem cells by means of bacterial artificial chromosome-based vectors and single-nucleotide polymorphism array-based detection. This system allowed us to generate human-induced pluripotent stem cell lines containing green fluorescence protein knocked into OSR1, a specific intermediate mesoderm marker. We have also established a robust induction protocol for intermediate mesoderm, which produces up to 90% OSR1(+) cells. These human intermediate mesoderm cells can differentiate into multiple cell types of intermediate mesoderm-derived organs in vitro and in vivo, thereby supplying a useful system to elucidate the mechanisms of intermediate mesoderm development and potentially providing a cell source for regenerative therapies of the kidney.


Assuntos
Células-Tronco Pluripotentes Induzidas/citologia , Rim/embriologia , Mesoderma/citologia , Mesoderma/embriologia , Animais , Diferenciação Celular , Linhagem Celular , Corpos Embrioides/citologia , Células-Tronco Embrionárias/citologia , Citometria de Fluxo , Dosagem de Genes/genética , Regulação da Expressão Gênica no Desenvolvimento , Técnicas de Introdução de Genes , Marcação de Genes , Loci Gênicos/genética , Proteínas de Fluorescência Verde/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Rim/citologia , Rim/metabolismo , Camundongos , Polimorfismo de Nucleotídeo Único/genética , Proteínas Serina-Treonina Quinases/metabolismo , Fatores de Tempo
16.
Biosci Biotechnol Biochem ; 72(8): 2074-81, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18685218

RESUMO

Pseudomonas sp. A-01, isolated as a strain with chitosan-degrading activity, produced a 28 kDa chitosanase. Following purification of the chitosanase (Cto1) and determination of its N-terminal amino acid sequence, the corresponding gene (cto1) was cloned by a reverse-genetic technique. The gene encoded a protein, composed of 266 amino acids, including a putative signal sequence (1-28), that showed an amino acid sequence similar to known family-46 chitosanases. Cto1 was successfully overproduced and was secreted by a Brevibacillus choshinensis transformant carrying the cto1 gene on expression plasmid vector pNCMO2. The purified recombinant Cto1 protein was stable at pH 5-8 and showed the best chitosan-hydrolyzing activity at pH 5. Replacement of two acidic amino acid residues, Glu23 and Asp41, which correspond to previously identified active centers in Streptomyces sp. N174 chitosanase, with Gln and Asn respectively caused a defect in the hydrolyzing activity of the enzyme.


Assuntos
Glicosídeo Hidrolases/metabolismo , Pseudomonas/enzimologia , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular , Sequência Conservada , Ativação Enzimática/efeitos dos fármacos , Glicosídeo Hidrolases/química , Glicosídeo Hidrolases/genética , Glicosídeo Hidrolases/isolamento & purificação , Hidrólise , Metais/farmacologia , Dados de Sequência Molecular , Mutação/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Especificidade por Substrato
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