1.Exploration of New Susceptible Genes associated with Non-Alcoholic Fatty Liver Disease among Children with Obesity Using Whole Exome Sequencing.
Xiong Feng PAN ; Cai Lian WEI ; Jia You LUO ; Jun Xia YAN ; Xiang XIAO ; Jie WANG ; Yan ZHONG ; Mi Yang LUO
Biomedical and Environmental Sciences 2025;38(6):727-739
OBJECTIVE:
This study aimed to evaluate the association between susceptibility genes and non-alcoholic fatty liver disease (NAFLD) in children with obesity.
METHODS:
We conducted a two-step case-control study. Ninety-three participants were subjected to whole-exome sequencing (exploratory set). Differential genes identified in the small sample were validated in 1,022 participants using multiplex polymerase chain reaction and high-throughput sequencing (validation set).
RESULTS:
In the exploratory set, 14 genes from the NAFLD-associated pathways were identified. In the validation set, after adjusting for sex, age, and body mass index, ECI2 rs2326408 (dominant model: OR = 1.33, 95% CI: 1.02-1.72; additive model: OR = 1.22, 95% CI: 1.01-1.47), C6orf201 rs659305 (dominant model: OR = 1.30, 95% CI: 1.01-1.69; additive model: OR = 1.21, 95% CI: 1.00-1.45), CALML5 rs10904516 (pre-ad dominant model: OR = 1.36, 95% CI: 1.01-1.83; adjusted dominant model: OR = 1.40, 95% CI: 1.03-1.91; and pre-ad additive model: OR = 1.26, 95% CI: 1.04-1.66) polymorphisms were significantly associated with NAFLD in children with obesity ( P < 0.05). Interaction analysis revealed that the gene-gene interaction model of CALML5 rs10904516, COX11 rs17209882, and SCD5 rs3733228 was optional ( P < 0.05), demonstrating a negative interaction between the three genes.
CONCLUSION
In the Chinese population, the CALML5 rs10904516, C6orf201 rs659305, and ECI2 rs2326408 variants could be genetic markers for NAFLD susceptibility.
Humans
;
Non-alcoholic Fatty Liver Disease/genetics*
;
Child
;
Male
;
Female
;
Genetic Predisposition to Disease
;
Case-Control Studies
;
Exome Sequencing
;
Adolescent
;
Polymorphism, Single Nucleotide
;
Obesity/complications*
;
Pediatric Obesity/complications*
;
China
2.Developing Syllabus for Rare Breast Diseases Using the Integrated Multimodality of Case-/Problem-/Resource-Based Learning
Ru YAO ; Jiahui ZHANG ; Jie LIAN ; Yang QU ; Xinyue ZHANG ; Xin HUANG ; Lu GAO ; Jun ZHAO ; Li HUANG ; Yingzi JIANG ; Linzhi LUO ; Songjie SHEN ; Feng MAO ; Qiang SUN ; Bo PAN ; Yidong ZHOU
JOURNAL OF RARE DISEASES 2024;3(3):391-399
Objective This study aims at establishing a teaching catalog and content for breast rare dis-eases and developing the syllabus for the breast rare disease using integrated multimodality of case-/problem-/resource-based learning(CBL+PBL+RBL).Methods By conducting bibliometrics co-occurrence analysis,we collected 6291 articles on breast rare disease published from January,1975 to June,2024.Additionally,we re-trieved the Textbook on Rare Diseases,the Catalog of Chinese Rare Disease,and Second Batch of Rare Dis-ease Catalog and then decided the teaching content.Results From 16,387 keywords,1000(6.1%)keywords were identified through co-occurrence analysis,including 50(0.3%)candidate diseases.These were classified into three categories:rare primary breast diseases,rare genetic mutation-related diseases associated with breast cancer,and rare systemic multi-system diseases involving the breast.From the candidate list,20(0.1%)rare primary breast diseases were further selected for their notable clinical teaching significance,and significant multi-systemic diseases affecting the breast,whether related to gene mutations or not.Teaching plans were draf-ted using a diversified parallel teaching approaches,taking into account the characteristics of different diseases and the focus of different teaching methods.Conclusions This study initiated the development of the teaching content for breast rare diseases and developed the teaching syllabus using the CBL+PBL+RBL integrated multi teaching model and targeting each rare breast disease for the critical point for teaching.
3.Diagnostic value of LP(a),D-D combined LAD for LATH in atrial fibrillation
Hong-Bin PAN ; Xiu-Feng LUO ; Lian ZENG ; Meng-Ju SHI
Chinese Journal of cardiovascular Rehabilitation Medicine 2023;32(6):600-603
Objective:To study diagnostic value of left atrial diameter(LAD),lipoprotein(a)[LP(a)]combined D-dimer(D-D)for left atrial thrombus(LATH)in patients with atrial fibrillation(AF).Methods:According to results of transesophageal echocardiography,a total of 367 AF patients treated in our hospital were divided into LATH group(n=67)and no LATH group(n=300).General clinical data,LAD,serum Lp(a)level and positive D-D rate were compared between two groups,and diagnostic value of above indexes for LATH in AF was ana-lyzed.Results:Compared with no LATH group,there were significant rise in LAD[(40.93±4.69)mm vs.(44.65±4.31)mm],serum Lp(a)level[(17.05±2.31)mg/dl vs.(27.42±3.06)mg/dl]and positive D-D rate(5.67%vs.22.34%)in LATH group(P=0.001 all).ROC curve indicated that AUC of Lp(a),positive D-D,LAD single detection and triple combined detection diagnosing LATH in AF was 0.711,0.584,0.728 and 0.801 respectively;sensitivity was 43.28%,22.39%,64.18%and 65.67%respectively;and specificity was 92.00%,94.33%,76.67%and 80.67%respectively.AUC of triple combined detection was significantly higher than that of any single detection,and sensitivity and specificity were significantly higher than those of Lp(a)and positive D-D single detection(P<0.05 or<0.01).Conclusion:Combined detection of Lp(a),positive D-D and LAD possess high diagnostic value for left atrial thrombus in atrial fibrillation.
4.A comparative study of artificial intelligence nasal polyp classification based on whole-slide imaging and JESREC diagnostic criteria.
Qing Wu WU ; Wei Feng KONG ; Lian Xiong YUAN ; Yong REN ; Ya Na ZHANG ; Hui Yi DENG ; Xin LUO ; Jian Ning CHEN ; Xue Kun HUANG ; Qin Tai YANG
Chinese Journal of Otorhinolaryngology Head and Neck Surgery 2022;57(2):136-141
Objective: To explore the types and clinical characteristics of chronic rhinosinusitis with nasal polyps (CRSwNP) based on artificial intelligence and whole-slide imaging (WSI), and to explore the consistency of the diagnostic criteria of the Japanese epidemiological survey of refractory eosinophilic chronic rhinosinusitis (JESREC) in Chinese CRSwNP patients. Methods: The data of 136 patients with CRSwNP (101 males and 35 females, aging 14 to 70 years) who underwent endoscopic sinus surgery from 2018 to 2019 in the Department of Otorhinolaryngology Head and Neck Surgery, the Third Affiliated Hospital of Sun Yat-sen University were analysed retrospectively. The preoperative clinical characteristics of patients were collected, such as visual analogue scale (VAS) of nasal symptoms, peripheral blood inflammatory cell count, total immunoglobulin E (IgE), Lund-Kennedy score and Lund-Mackay score. The proportion of inflammatory cells such as eosinophils, lymphocytes, plasma cells and neutrophils were calculated on the WSI of each patient through artificial intelligence chronic rhinosinusitis evaluation platform 2.0 (AICEP 2.0), and the specific type of nasal polyps was then obtained as eosinophilic CRSwNP (eCRSwNP) or non-eosinophilic CRSwNP (non-eCRSwNP). In addition, the JESREC diagnostic criteria was used to classify the nasal polyps, and the classification results were compared with the current gold standard for nasal polyps diagnosis (pathological diagnosis based on WSI). The accuracy, sensitivity and specificity of the diagnostic criteria of JESREC were evaluated. The data were expressed in M (Q1, Q3) and statistically analyzed by SPSS 17.0. Results: There was no significant difference between eCRSwNP and non-eCRSwNP in age distribution, gender, time of onset, total VAS score, Lund-Kennedy score or Lund-Mackay score. However, there was a significant difference in the ratio of nasal polyp inflammatory cells (eosinophils 40.5% (22.8%, 54.7%) vs 2.5% (1.0%, 5.3%), neutrophils 0.3% (0.1%, 0.7%) vs 1.3% (0.5%, 3.6%), lymphocytes 49.9% (39.3%, 65.9%) vs 82.0% (72.8%, 87.5%), plasma cells 5.1% (3.6%, 10.5%) vs 13.0% (7.4%, 16.3%), χ2 value was 9.91, 4.66, 8.28, 5.06, respectively, all P<0.05). In addition, eCRSwNP had a significantly higher level of proportion of allergic symptoms (nasal itching and sneezing), asthma, peripheral blood eosinophil and total IgE (all P<0.05). The overall accuracy, sensitivity and specificity of the JESREC diagnostic criteria was 74.3%, 81.3% and 64.3%, respectively. Conclusions: The eCRSwNP based on artificial intelligence and WSI has significant high level of allergic symptoms, asthma, peripheral blood eosinophils and total IgE, and the percentages of inflammatory cells in nasal polyps are different from that of non-eCRSwNP. The JESREC diagnostic criteria has good consistency in our research.
Artificial Intelligence
;
Chronic Disease
;
Eosinophils/metabolism*
;
Female
;
Humans
;
Male
;
Nasal Polyps/pathology*
;
Retrospective Studies
;
Rhinitis/pathology*
;
Sinusitis/pathology*
5.Genotype-phenotype landscape of pituitary adrenocorticotroph hormone adenoma
Hui MIAO ; Luo WANG ; Fengying GONG ; Lian DUAN ; Linjie WANG ; Yong YAO ; Ming FENG ; Kan DENG ; Renzhi WANG ; Yanfang GUAN ; Huijuan ZHU ; Lin LU
Chinese Journal of Endocrinology and Metabolism 2022;38(2):125-131
Objective:Cushing′s disease(CD) is caused by the pituitary adrenocorticotroph hormone(ACTH) secreting adenomas, leading to increased serum cortisol levels and various abnormal metabolic processes. Untreated CD is linked to high mortality, thus it is critical to elucidate its pathogenesis. This study aims to explore the pathogenesis of pituitary ACTH adenomas using whole-genome sequencing analysis.Methods:Fresh tumor tissues and peripheral blood samples were collected in 9 confirmed cases of pituitary ACTH adenomas who underwent surgery. Whole genome sequencing was then performed, followed by analysis and verification of single nucleotide mutations, copy number variation(CNV) and chromosome structure variations.Results:Somatic USP8 mutations(p.Ser718del, p. Ser718Pro, p. Pro720Arg, p. Pro720Gln) were found in 5 patients, with a rate of 55.6%; CNV of USP8 was detected in 1 patient; TP53(p.Cys135Tyr), NF1(p.Val1049Glufs*11) and KMT2C(c.3323+ 1G>A) mutations were identified in 1 patient harboring wild-type USP8. CNV analysis showed a loss of heterozygosity in multiple chromosomes in a wild-type USP8 patient. Structural variations were found in 2 with unknown significance. No germline gene mutations were detected in this study.Conclusion:Somatic USP8 mutations, increased copy number of USP8, variations of tumor-related genes such as TP53 and extensive somatic CNV all contribute to pathogenesis of CD. Chromosomal structure variations may suggest high-risk pituitary ACTH adenomas, and call for frequent follow-up and aggressive treatment.
6. Efficacy and safety of alfentanil hydrochloride injection in general anesthesia: A multicenter, double-blind, controlled study
Ming-Hua CHEN ; Yi FENG ; Kai-Ming DUAN ; Wen OUYANG ; Sai-Ving WANG ; Fu-Shan XUE ; Ming-Hua CHEN ; Fu-Shan XUE ; Yi FENG ; Ai-Lin LUO ; Qu-Lian GUO ; Ya-Ping WANG ; Deng-Bin AI ; Gong-Jian LIU ; Kai-Ming DUAN ; Wen OUYANG ; Sai-Ving WANG ; Ai-Lin LUO ; Qu-Lian GUO ; Ya-Ping WANG ; Deng-Bin AI ; Gong-Jian LIU
Chinese Pharmacological Bulletin 2022;38(10):1504-1510
Aim To investigate the effectiveness and safety of alfentanil in general anesthesia.Methods In this study, a multicenter randomized double-blind con¬trolled study was conducted.A total of 352 subjects were selected and randomly assigned to fentanyl group (group A, n =176) and alfentanil group (group 15, n = 176).Anesthesia induction: intravenous midazolam 0.03 mg • kg-1 + fentanyl 25 p.g • kg"'(group A) or alfentanil 4 p,g • kg-1 ( group 15) + propofol 2 mg • kg"1 + rocuronium 0.8 mg • kg"1.Sevoflurane + fent¬anyl ( group A ) or alfentanil ( group B ) + rocuronium were used for anesthesia.The vital signs of patients re¬covery time and extuhation time, anesthesia-related complications and the use of related remedial drugs during anesthesia induction and maintenance were compared between the two groups.Results During the induction and maintenance period of anesthesia, alfentanil and fentanyl could equally effectively inhibit the stress response induced by endotracheal intubation and surgical stimulation.Alfentanil also showed more effective inhibition on stress response induced by endo¬tracheal intubation and surgical stimulation than that of fentanyl ( P < 0.05 ) .However, there was no signifi¬cant difference in the incidence of intraoperative hypo¬tension and hypertension and the time of anesthesia re¬covery and extubation between the two groups.Conclu¬sions Both alfentanil and fentanyl can effectively in¬hibit the stress response induced by surgical stimulation and could be safely used in general anesthesia in sur¬gery.Alfentanil has more advantages in maintaining the stability of blood pressure and heart rate during an¬esthesia induction and maintenance.
7.A multicenter epidemiological study of acute bacterial meningitis in children.
Cai Yun WANG ; Hong Mei XU ; Jiao TIAN ; Si Qi HONG ; Gang LIU ; Si Xuan WANG ; Feng GAO ; Jing LIU ; Fu Rong LIU ; Hui YU ; Xia WU ; Bi Quan CHEN ; Fang Fang SHEN ; Guo ZHENG ; Jie YU ; Min SHU ; Lu LIU ; Li Jun DU ; Pei LI ; Zhi Wei XU ; Meng Quan ZHU ; Li Su HUANG ; He Yu HUANG ; Hai Bo LI ; Yuan Yuan HUANG ; Dong WANG ; Fang WU ; Song Ting BAI ; Jing Jing TANG ; Qing Wen SHAN ; Lian Cheng LAN ; Chun Hui ZHU ; Yan XIONG ; Jian Mei TIAN ; Jia Hui WU ; Jian Hua HAO ; Hui Ya ZHAO ; Ai Wei LIN ; Shuang Shuang SONG ; Dao Jiong LIN ; Qiong Hua ZHOU ; Yu Ping GUO ; Jin Zhun WU ; Xiao Qing YANG ; Xin Hua ZHANG ; Ying GUO ; Qing CAO ; Li Juan LUO ; Zhong Bin TAO ; Wen Kai YANG ; Yong Kang ZHOU ; Yuan CHEN ; Li Jie FENG ; Guo Long ZHU ; Yan Hong ZHANG ; Ping XUE ; Xiao Qin LI ; Zheng Zhen TANG ; De Hui ZHANG ; Xue Wen SU ; Zheng Hai QU ; Ying ZHANG ; Shi Yong ZHAO ; Zheng Hong QI ; Lin PANG ; Cai Ying WANG ; Hui Ling DENG ; Xing Lou LIU ; Ying Hu CHEN ; Sainan SHU
Chinese Journal of Pediatrics 2022;60(10):1045-1053
Objective: To analyze the clinical epidemiological characteristics including composition of pathogens , clinical characteristics, and disease prognosis acute bacterial meningitis (ABM) in Chinese children. Methods: A retrospective analysis was performed on the clinical and laboratory data of 1 610 children <15 years of age with ABM in 33 tertiary hospitals in China from January 2019 to December 2020. Patients were divided into different groups according to age,<28 days group, 28 days to <3 months group, 3 months to <1 year group, 1-<5 years of age group, 5-<15 years of age group; etiology confirmed group and clinically diagnosed group according to etiology diagnosis. Non-numeric variables were analyzed with the Chi-square test or Fisher's exact test, while non-normal distrituction numeric variables were compared with nonparametric test. Results: Among 1 610 children with ABM, 955 were male and 650 were female (5 cases were not provided with gender information), and the age of onset was 1.5 (0.5, 5.5) months. There were 588 cases age from <28 days, 462 cases age from 28 days to <3 months, 302 cases age from 3 months to <1 year of age group, 156 cases in the 1-<5 years of age and 101 cases in the 5-<15 years of age. The detection rates were 38.8% (95/245) and 31.5% (70/222) of Escherichia coli and 27.8% (68/245) and 35.1% (78/222) of Streptococcus agalactiae in infants younger than 28 days of age and 28 days to 3 months of age; the detection rates of Streptococcus pneumonia, Escherichia coli, and Streptococcus agalactiae were 34.3% (61/178), 14.0% (25/178) and 13.5% (24/178) in the 3 months of age to <1 year of age group; the dominant pathogens were Streptococcus pneumoniae and the detection rate were 67.9% (74/109) and 44.4% (16/36) in the 1-<5 years of age and 5-<15 years of age . There were 9.7% (19/195) strains of Escherichia coli producing ultra-broad-spectrum β-lactamases. The positive rates of cerebrospinal fluid (CSF) culture and blood culture were 32.2% (515/1 598) and 25.0% (400/1 598), while 38.2% (126/330)and 25.3% (21/83) in CSF metagenomics next generation sequencing and Streptococcus pneumoniae antigen detection. There were 4.3% (32/790) cases of which CSF white blood cell counts were normal in etiology confirmed group. Among 1 610 children with ABM, main intracranial imaging complications were subdural effusion and (or) empyema in 349 cases (21.7%), hydrocephalus in 233 cases (14.5%), brain abscess in 178 cases (11.1%), and other cerebrovascular diseases, including encephalomalacia, cerebral infarction, and encephalatrophy, in 174 cases (10.8%). Among the 166 cases (10.3%) with unfavorable outcome, 32 cases (2.0%) died among whom 24 cases died before 1 year of age, and 37 cases (2.3%) had recurrence among whom 25 cases had recurrence within 3 weeks. The incidences of subdural effusion and (or) empyema, brain abscess and ependymitis in the etiology confirmed group were significantly higher than those in the clinically diagnosed group (26.2% (207/790) vs. 17.3% (142/820), 13.0% (103/790) vs. 9.1% (75/820), 4.6% (36/790) vs. 2.7% (22/820), χ2=18.71, 6.20, 4.07, all P<0.05), but there was no significant difference in the unfavorable outcomes, mortility, and recurrence between these 2 groups (all P>0.05). Conclusions: The onset age of ABM in children is usually within 1 year of age, especially <3 months. The common pathogens in infants <3 months of age are Escherichia coli and Streptococcus agalactiae, and the dominant pathogen in infant ≥3 months is Streptococcus pneumoniae. Subdural effusion and (or) empyema and hydrocephalus are common complications. ABM should not be excluded even if CSF white blood cell counts is within normal range. Standardized bacteriological examination should be paid more attention to increase the pathogenic detection rate. Non-culture CSF detection methods may facilitate the pathogenic diagnosis.
Adolescent
;
Brain Abscess
;
Child
;
Child, Preschool
;
Escherichia coli
;
Female
;
Humans
;
Hydrocephalus
;
Infant
;
Infant, Newborn
;
Male
;
Meningitis, Bacterial/epidemiology*
;
Retrospective Studies
;
Streptococcus agalactiae
;
Streptococcus pneumoniae
;
Subdural Effusion
;
beta-Lactamases
8.Effect of glucose metabolism disorders on the short-term prognosis in neonates with asphyxia: a multicenter study in Hubei Province, China.
Chun-Hua LIU ; Hui WANG ; Si-Cong PENG ; Wen-Xiang WANG ; Rong JIAO ; Sha PAN ; Tian-Jiao ZHU ; Xiao-Ying LUAN ; Xiao-Fang ZHU ; Su-Ying WU ; De-Guo WEI ; Bing-Feng FU ; Rui-Hong YAN ; Shu-Jie YANG ; Ya-Hui LUO ; Gui-Ping LI ; Min YANG ; De-Zhao JIA ; Chuang GAO ; Xiong-Fei XIAO ; Li XIONG ; Jie SUN ; Jia-Peng XIAO ; Bo-Wen LI ; Yan-Ni LI ; Lian-Hong ZHANG ; Tian-Guo LI ; Min CHENG ; Jian-Xin XIA ; Shi-Wen XIA
Chinese Journal of Contemporary Pediatrics 2021;23(12):1208-1213
OBJECTIVES:
To study the effect of glucose metabolism disorders on the short-term prognosis in neonates with asphyxia.
METHODS:
A retrospective analysis was performed on the medical data of the neonates with asphyxia who were admitted to 52 hospitals in Hubei Province of China from January to December, 2018 and had blood glucose data within 12 hours after birth. Their blood glucose data at 1, 2, 6, and 12 hours after birth (with an allowable time error of 0.5 hour) were recorded. According to the presence or absence of brain injury and/or death during hospitalization, the neonates were divided into a poor prognosis group with 693 neonates and a good prognosis group with 779 neonates. The two groups were compared in the incidence of glucose metabolism disorders within 12 hours after birth and short-term prognosis.
RESULTS:
Compared with the good prognosis group, the poor prognosis group had a significantly higher proportion of neonates from secondary hospitals (48.5% vs 42.6%,
CONCLUSIONS
Recurrent hyperglycemia in neonates with asphyxia may suggest poor short-term prognosis, and it is necessary to strengthen the early monitoring and management of the nervous system in such neonates.
Asphyxia
;
Asphyxia Neonatorum/epidemiology*
;
Humans
;
Hyperglycemia
;
Infant, Newborn
;
Prognosis
;
Retrospective Studies
9. Investigation of treatment and analysis of prognostic risk on enterocutaneous fistula in China: a multicenter prospective study
Tao ZHENG ; Haohao XIE ; Xiuwen WU ; Qiang CHI ; Feng WANG ; Zhenhua YANG ; Chaowu CHEN ; Wei MAI ; Suming LUO ; Xiaofei SONG ; Shimin YANG ; Wei ZHOU ; Haiyan LIU ; Xinjian XU ; Zheng ZHOU ; Chuanyuan LIU ; Lian′an DING ; Kai XIE ; Gang HAN ; Hongbin LIU ; Jianzhong WANG ; Shichen WANG ; Peige WANG ; Gefei WANG ; Guosheng GU ; Jian′an REN
Chinese Journal of Gastrointestinal Surgery 2019;22(11):1041-1050
Objective:
To investigate the diagnosis and treatment for enterocutaneous fistula (ECF) in China, and to explore the prognostic factors of ECF.
Methods:
A multi-center cross-sectional study was conducted based on the Registration System of Chinese Gastrointestinal Fistula and Intra-Abdominal Infections to collect the clinical data of ECF patients from 54 medical centers in 22 provinces/municipalities from January 1, 2018 to December 31, 2018. The clinical data included patient gender, age, length of hospital stay, intensive care unit (ICU) admission, underlying diseases, primary diseases, direct causes of ECF, location and type of ECF, complications, treatment and outcomes. All medical records were carefully filled in by the attending physicians, and then re-examined by more than two specialists. The diagnosis of ECF was based on the clinical manifestations, laboratory/imaging findings and intraoperative exploration.
Results:
A total of 1521 patients with ECF were enrolled, including 1099 males and 422 females, with a median age of 55 years. The top three primary diseases of ECF were malignant tumors in 626 cases (41.2%, including 540 gastrointestinal tumors, accounting for 86.3% of malignant tumors), gastrointestinal ulcers and perforations in 202 cases (13.3%), and trauma in 157 cases (10.3%). The direct causes of ECF were mainly surgical operation in 1194 cases (78.5%), followed by trauma in 156 (10.3%), spontaneous fistula due to Crohn
10.Cloning and characterization of an oxiranedicarboxylate hydrolase from Labrys sp. WH-1.
Wen-Na BAO ; Zi-Sheng LUO ; Shi-Wang LIU ; Yuan-Feng WU ; Pei-Lian WEI ; Gong-Nian XIAO ; Yong LIU
Journal of Zhejiang University. Science. B 2019;20(12):995-1002
OBJECTIVE:
This study aimed to clone and characterize the oxiranedicarboxylate hydrolase (ORCH) from Labrys sp. WH-1.
METHODS:
Purification by column chromatography, characterization of enzymatic properties, gene cloning by protein terminal sequencing and polymerase chain reaction (PCR), and sequence analysis by secondary structure prediction and multiple sequence alignment were performed.
RESULTS:
The ORCH from Labrys sp. WH-1 was purified 26-fold with a yield of 12.7%. It is a monomer with an isoelectric point (pI) of 8.57 and molecular mass of 30.2 kDa. It was stable up to 55 °C with temperature at which the activity of the enzyme decreased by 50% in 15 min (T5015) of 61 °C and the half-life at 50 °C (t1/2, 50 °C) of 51 min and was also stable from pH 4 to 10, with maximum activity at 55 °C and pH 8.5. It is a metal-independent enzyme and strongly inhibited by Cu2+, Ag+, and anionic surfactants. Its kinetic parameters (Km, kcat, and kcat/Km) were 18.7 mmol/L, 222.3 s-1, and 11.9 mmol/(L·s), respectively. The ORCH gene, which contained an open reading frame (ORF) of 825 bp encoding 274 amino acid residues, was overexpressed in Escherichia coli and the enzyme activity was 33 times higher than that of the wild strain.
CONCLUSIONS
The catalytic efficiency and thermal stability of the ORCH from Labrys sp. WH-1 were the best among the reported ORCHs, and it provides an alternative catalyst for preparation of L(+)-2,3-dihydrobutanedioic acid.
Alphaproteobacteria/enzymology*
;
Cloning, Molecular
;
Dicarboxylic Acids/metabolism*
;
Enzyme Stability
;
Epoxide Hydrolases/metabolism*

Result Analysis
Print
Save
E-mail