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root uv-b sensitive Mutants Are Suppressed by Specific Mutations in aspartate aminotransferase2 and by Exogenous Vitamin B6

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Molecular Plant 2011年第4期4卷 759-770页

作者： Colin D. Leasure Hong-Yun Tong Xue-Wen Hou Amy Shelton Mike Minton Raymond Esquerra Sanja Roje Hanjo Hellmann Zheng-Hui He Department of Biology 1600 Holloway Avenue San Francisco State University San Francisco CA 94132 USA Department of Chemistry and Biochemistry 1600 Holloway Avenue San Francisco State University San Francisco CA 94132 USA The Institute of Biological Chemistry Washington State University Pullman WA 99164 USA School of Biological Sciences Washington State University Pullman WA 99164 USA

Vitamin B6 （vitB6） serves as an essential cofactor for more than 140 enzymes. Pyridoxal 5＇-phosphate （PLP）, active cofactor form of vitB6, can be photolytically destroyed by trace amounts of ultraviolet-B （UV-B）. How sun-exposed organisms cope with PLP photosensitivity and modulate vitB6 homeostasis is currently unknown. We previously reported on two Arabidopsis mutants, rusl and rus2, that are hypersensitive to trace amounts of UV-B light. We performed mutagenesis screens for second-site suppressors of the rus mutant phenotype and identified mutations in the aspartate aminotransferase2 （ASP2） gene. ASP2 encodes for cytosolic aspartate aminotransferase （AAT）, a PLP-dependent enzyme that plays a key role in carbon and nitrogen metabolism. Genetic analyses have shown that specific amino acid substitutions in ASP2 override the phenotypes of rusl and rus2 single mutants as well as rusl rus2 double mutant. These substitutions, all shown to reside at specific positions in the PLP-binding pocket, resulted in no PLP binding. Additional asp2 mutants that abolish AAT enzymatic activity, but which alter amino acids outside of the PLP-binding pocket, fail to suppress the rus phenotype. Furthermore, exogenously adding vitB6 in growth media can rescue both rusl and rus2. Our data suggest that AAT plays a role in vitB6 homeostasis in Arabidopsis.

关键词： Vitamin B6 pyridoxal-phosphate aspartate aminotransferase ultraviolet light photo protection.

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Serum γ-glutamyltransferase,alanine aminotransferase,and aspartate aminotransferase activity in Iranian healthy blood donor men

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World Journal of Gastroenterology 2007年第6期13卷 889-894页

作者： Hossein Khedmat Farahnaz Fallahian Hassan Abolghasemi Bashir Hajibeigi Zohre Attarchi Farshid Alaeddini Mohammad Taghi Holisaz Masoumeh Pourali Shahin Sharifi Nasrin Zarei Baqiyatallah University of Medical Sciences Iran Iranian Blood Transfusion Organization Research Center Tehran Iran

AIM: To determine serum γ-glutamyltransferase (GGT), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) activity, and to assess their correlation with demographic and clinical findings in healthy blood donors. METHODS: This cross-sectional study was performed in 934 male blood donors, aged 18 to 68 years, who consecutively attended Tehran blood transfusion service in 2006. All participants were seronegative for HBV or HCV infections, non alcohol users, and all underwent a standard interview and anthropometric tests. Clinical and biochemical parameters including AST, ALT, and GGT activities were determined. Patients taking drugs known to cause hepatic fat deposition were excluded. For AST, ALT, and GGT variables, we used 33.33 and 66.66 percentiles, so that each of them was divided into three tertiles. RESULTS: Mean AST, ALT, and GGT activities were 25.26 ± 12.58 U/L (normal range 5-35 U/L), 33.13 ± 22.98 (normal range 5-35 U/L), and 25.11 ± 18.32 (normal range 6-37 U/L), respectively. By univariate analyses, there were significant associations between increasing AST, ALT, or GGT tertiles and age, body weight, body mass index, and waist and hip circumferences (P < 0.05). By multiple linear regression analyses, ALT was found to be positively correlated with dyslipidemia (B = 6.988, P = 0.038), whereas ALT and AST were negatively correlated with age. AST, ALT, and GGT levels had positive correlation with family history of liver disease (B = 15.763, P < 0.001), (B = 32.345, P < 0.001), (B =24.415, P < 0.001), ***: Although we did not determine the cutoffs of the upper normal limits for AST, ALT, and GGT levels, we would suggest screening asymptomatic patients with dyslipidemia and also subjects with a family history of liver disease.

关键词： γ-glutamyltransferase Alanine aminotransrerase aspartate aminotransferase Blood donor

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Development of Enzyme Biosensor for Amperometric Measurement of aspartate aminotransferase

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稀有金属材料与工程 2006年第A3期35卷 330-332页

作者： Zonghui Guo Chunxiu Liu Huaqing Li Jianfang Xu Lianshi Feng Xinxia Cai State Key Laboratory of Transducer Technology Institute of Electronics Chinese Academy of Sciences Beijing 100080 China Graduate School of Chinese Academy of Science Beijing 100080 China Biology Center China Institute of Sport Science Beijing 100080 China

An enzyme biosensor for amperometric measurement of aspartate aminotransferase has been *** working electrode was modified with a thin-film of redox polymer,then glutamate oxidase,with the immobilized reagent cast and dried on the *** biosensor responses to AST by detecting hydrogen peroxide were produced by enzymical reaction at-0.1 V with a response time of 120 *** electrode gave a detection limit of 32.5 U/L with a linear concentration range of 32.5 U/L～2000 U/L in *** to more sensitive and lower detection limit,the biosensor is expected mainly to be used for physiological identification and physical performance of athletes in the *** application will also affect the practice of clinical medicine for the diagnosis of heart and liver disease.

关键词： aspartate aminotransferase redox polymer amperometric biosensor

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Isolated elevated aspartate aminotransferase in an asymptomatic woman due to macro-aspartate aminotransferase: A case report

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World Journal of Clinical Cases 2019年第24期7卷 4414-4419页

作者： Meng-Ru Zhan Xu Liu Ming-Yuan Zhang Jun-Qi Niu Department of Hepatology The First Hospital of Jilin University

BACKGROUND Macro-aspartate aminotransferase(AST), a macroenzyme, is a high-molecular mass complex formed by self-polymerization or association with other serum components that are difficult for the kidney to clear, leading to the isolated elevation of serum AST activity. Cases of macro-AST formation are rare, with only 3 published in the English language literature up to September 2019 in China. In this paper, we present a case in which an asymptomatic woman with persistent isolated elevated AST was confirmed as having macro-AST by the polyethylene glycol precipitation *** SUMMARY A 34-year-old woman was referred to our clinic for elevated AST levels with normal levels of other liver-associated enzymes on November 12, 2018. Her AST level of liver function test had been abnormal for 7 mo before she came to the clinic. The patient was asymptomatic with a normal physical examination. There was no relevant family history and no alcohol consumption or smoking. She had a several-month history of traditional Chinese medical taking and had stopped it 1 year prior. The laboratory tests in our clinic showed only the elevation of AST(89.5 U/L) with no other significant abnormalities. We performed the precipitation technique with polyethylene glycol to confirm the presence of macro-AST. Then for almost a year, her AST level still fluctuated in the abnormal *** This case highlights that clinical physicians should be familiar with this rare condition of persistent isolated AST elevation due to the presence of macro-AST to avoid unnecessary investigation and patient anxiety.

关键词： aspartate aminotransferase Macroenzymes Macro-aspartate aminotransferase Polyethylene glycol precipitation method China Case report

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Development of Enzyme Biosensor for Amperometric Measurement of aspartate aminotransferase

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稀有金属材料与工程 2006年第S3期 330-332页

作者： Zonghui Guo~(1,2) Chunxiu Liu~(1,2) Huaqing Li~(1,2) Jianfang Xu~3 Lianshi Feng~3 Xinxia Cai~(1,*) (1.State Key Laboratory of Transducer Technology,Institute of Electronics,Chinese Academy of Sciences,Beijing 100080,China) (2.Graduate School of Chinese Academy of Science,Beijing 100080,China) (3.Biology Center China Institute of Sport Science,Beijing 100080,China)

关键词： aspartate aminotransferase redox polymer amperometric biosensor

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Recombinant aspartate aminotransferase-catalyzed synthesis of L-4-fluorophenylalanine

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Frontiers of Chemical Science and Engineering 2008年第2期2卷 220-223页

作者： Meijuan CHEN Honghua JIA Yongsheng CHEN Min JIANG Ping WEI College of Life Science and Pharmacy Nanjing University of TechnologyNanjing 210009China

L-4-Fluorophenylalanine(FPhe)was prepared from 4-fluorophenylpyruvate(FPPA)catalyzed by aspartate aminotransferase(Asp-AT)of the recombinant *** BL21-pET/*** 12 h enzymatic reaction,the FPPA conversion was over 90%and the yield of FPhe could be above 85%under the following optimal conditions:37uC,pH value range of 5.0–8.0,5.5 mass ratio of cell to FPPA,0.6%(w/v)of Tween 80,7.08 g/L FPPA,and 1.6 of molar ratio of L-Asp to FPPA.

关键词： L-4-fluorophenylalanine 4-fluorophenylpyruvate aspartate aminotransferase

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Longitudinal Changes in Liver aminotransferases Predict Metabolic Syndrome in Chinese Patients with Nonviral Hepatitis

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Biomedical and Environmental Sciences 2016年第4期29卷 254-266页

作者： CHEN Qi Cai XIAO Juan ZHANG Peng Peng CHEN Li Li CHEN Xiao Xiao WANG Shu Mei Department of Prevention and Health Care Dongying Shengli Oilfield Central Hospital Dongying 257000 Shandong China Department of Epidemiology School of Public Health Shandong University Jinan 250012 Shandong China Tianjin Entry-Exit Inspection and Quarantine Bureau Tianjin 300000 China Department of Nutrition and Food Safety Zhejiang Center for Disease Control and Prevention Hangzhou 310051 Zhejiang China

Objective This study explored the correlation of longitudinal changes in serum alanine aminotransferase （ALT） and aspartate aminotransferase （AST） levels with the incidence of metabolic syndrome （Mets） based on a dynamic health examination cohort. Methods A Mets-free dynamic cohort involving 4541 participants who underwent at least three health examinations from 2006 to 2011 was included in the study. Mets was defined according to the Chinese Medical Association Diabetes Branch definition that included hypertension, obesity, hyperlipidemia, and hyperglycemia. Generalized estimating equation （GEE） model was used to analyze multivariate relative risk （RR） of repeated observations of ALT and AST in quartiles for Mets or its components according to gender. Results In all, 826 Mets cases were reported. Adjustment of relevant parameters indicated that time-varying changes in ALT and AST levels were positively associated with the incidence of Mets in a dose-response manner. Positive association between high ALT levels and fatty liver was much stronger than that between high AST levels and fatty liver, particularly in male participants. These associations were consistently observed in the following subgroups： participants with ALT and AST levels of 〈40 U/L, participants with of 〈25 kg/m2, and participants with non-fatty liver. Furthermore, participants with 2 Mets components at baseline showed lower multivariate adjusted RRs of ALT and AST for Mets than participants with 0-1 Mets component. Conclusion These results suggested that elevated serum ALT and AST levels were early biomarkers of Mets or its components.

关键词： Alanine aminotransferase aspartate aminotransferase Metabolic syndrome Dynamic cohortstudy Generalized estimating equation model

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Characterization of Lysine Monomethylome and Methyltransferase in Model Cyanobacterium Synechocystis *** 6803

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Genomics, Proteomics & Bioinformatics 2020年第3期18卷 289-304页

作者： Xiaohuang Lin Mingkun Yang Xin Liu Zhongyi Cheng Feng Ge State Key Laboratory of Freshwater Ecology and Biotechnology Institute of HydrobiologyChinese Academy of SciencesWuhan 430072China Key Laboratory of Algal Biology Institute of HydrobiologyChinese Academy of SciencesWuhan 430072China University of Chinese Academy of Sciences Beijing 100039China Jingjie PTM BioLab(Hangzhou)Co.Ltd Hangzhou 310018China

Protein lysine methylation is a prevalent post-translational modification(PTM)and plays critical roles in all domains of ***,its extent and function in photosynthetic organisms are still largely *** are a large group of prokaryotes that carry out oxygenic photosynthesis and are applied extensively in studies of photosynthetic mechanisms and environmental *** we integrated propionylation of monomethylated proteins,enrichment of the modified peptides,and mass spectrometry(MS)analysis to identify monomethylated proteins in Synechocystis *** 6803(Synechocystis).Overall,we identified 376 monomethylation sites in270 proteins,with numerous monomethylated proteins participating in photosynthesis and carbon *** subsequently demonstrated that Cpc M,a previously identified asparagine methyltransferase in Synechocystis,could catalyze lysine monomethylation of the potential aspartate aminotransferase Sll0480 both in vivo and in vitro and regulate the enzyme activity of *** loss of Cpc M led to decreases in the maximum quantum yield in primary photosystemⅡ(PSⅡ)and the efficiency of energy transfer during the photosynthetic reaction in *** report the first lysine monomethylome in a photosynthetic organism and present a critical database for functional analyses of monomethylation in *** large number of monomethylated proteins and the identification of Cpc M as the lysine methyltransferase in cyanobacteria suggest that reversible methylation may influence the metabolic process and photosynthesis in both cyanobacteria and plants.

关键词： Cyanobacteria Lysine monomethylation Lysine methyltransferase Post-translational modification aspartate aminotransferase

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Associations between y-glutamyl transferase, metabolic abnormalities and inflammation in healthy subjects from a population-based cohort: A possible implication for oxidative stress

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World Journal of Gastroenterology 2005年第45期11卷 7109-7117页

作者： Simona Bo Roberto Gambino Marilena Durazzo Sabrina Guidi Elisa Tiozzo Federica Ghione Luigi Gentile Maurizio Cassader Gian Franco Pagano Department of Internal Medicine Diabetic Clinic

AIM: To examine the relationships between γ -glutamyltransferase (GGT), alanine-aminotransferase (ALT),aspartate-aminotransferase (AST) and various metabolic parameters, C-reactive protein (CRP) and an oxidative stress marker (nitrotyrosine, NT) in subjects without any metabolic abnormalities from a population-based ***: Two hundred and five subjects with normal body mass index (BMI), glucose tolerance, and without any metabolic abnormality were studied out of 1339subjects, without known liver diseases, alcohol abuse or use of hepatotoxic drugs, who are representative of the 45-64 aged population of Asti (north-western Italy).RESULTS: In all patients metabolic parameters and hs-CRP levels linearly increase from the lowest to the highest ALT and GGT tertiles, while in subjects without metabolic abnormalities, there is a significant association between fasting glucose, uric acid, waist circumference,hs-CRP, triglyceride values, and GGT levels. In these subjects, male sex, higher hs-CRP and glucose levels are associated with GGT levels in a multiple regression model, after adjustments for multiple *** the same model, median NT levels are significantly associated with the increasing GGT tertile (β = 1.06;95%CI 0.67-1.45), but not with the AST and ALT *** a multiple regression model, after adjusting for age,sex, BMI, waist, smoking, and alcohol consumption, both NT (β = 0.05; 95%CI 0.02-0.08) and hs-CRP levels (β =0.09; 95%CI 0.03-0.15) are significantly associated with fasting ***: GGT, an easy, universally standardized and available measurement, could represent an early marker of sub-clinical inflammation and oxidative stress in otherwise healthy individuals. Prospective studies are needed to establish if GGT could predict future diabetes in these subjects.

关键词： Alanine aminotransferase aspartate aminotransferase Body mass index C-reactive protein γ-Glutamyl transferase Metabolic syndrome Nitrotyrosine

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AST-to-ALT ratio and coronary artery lesions among patients with Kawasaki disease

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World Journal of Pediatrics 2021年第6期17卷 659-668页

作者： Lei Cao Yun-Jia Tang Miao Gang Jin Ma Wei-Guo Qian Qiu-Qin Xu Hai-Tao Lv Department of Cardiology Children's Hospital of Soochow UniversityNo.92Zhongnan StreetSuzhouChina Department of Pharmacy Children's Hospital of Soochow UniversityNo 92Zhongnan StreetSuzhou.China

Background The aim of this study was to explore the associations between the aspartate aminotransferase-to-alanine aminotransferase ratio(AST/ALT)and coronary artery lesions(CALs)among patients with Kawasaki disease(KD).Methods Medical records of KD patients presenting to a single center between January 2019 and December 2020 were retrospectively collected and ***,multivariable-adjusted analyses,subgroup analyses,restricted cubic spline test,and fitted curves were used to evaluate the associations between AST/ALT and *** A total of 831 patients were enrolled,of which 201(24.2%)had CALs on admission and 21(2.5%)developed CALs de novo after intravenous immunoglobulin(IVIG).Multivariable-adjusted analyses models revealed that a lower AST/ALT was associated with an increased risk of CALs on admission when AST/ALT was a continuous variable(P=0.007)and when it was a categorical variable(P for trend=0.004).Each unit increase in AST/ALT was associated with a 22%lower risk of CALs on admission(odds ratio=0.78,95%confidence interval 0.65-0.94).A negative linear relationship was noted between AST/ALT and the risk of CALs on admission in both observed and fitted ***,such associations were not observed in AST/ALT and CALs de novo after *** of the variables significantly modified the association between AST/ALT and CALs on admission and CALs de novo after IVIG(P>0.05).Conclusion Our findings suggested that AST/ALT was a risk factor of CALs,but was not associated with progressive CALs.

关键词： Alanine aminotransferase aspartate aminotransferase Coronary artery lesions Kawasaki disease

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