1.Dihuang Yinzi Improves Cognitive Function of Mouse Model of Learning and Memory Impairments by Regulating Synaptic Plasticity via SIRT2
Wenting WANG ; Yangjing HAO ; Wenna SU ; Qinqing LI ; Shifeng CHU ; Junlong ZHANG ; Wenbin HE
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(6):9-17
ObjectiveTo investigate the effects of Dihuang Yinzi on the cognitive function in the mouse model of learning and memory impairments induced by scopolamine (SCOP) and explore the treatment mechanism. MethodsA mouse model of learning and memory impairment was induced by intraperitoneal injection of SCOP. Sixty male C57BL/6J mice were randomized into six groups: control (0.9% NaCl, n=10), model (SCOP 1 mg·kg-1·d-1, n=10), low-, medium-, and high-dose Dihuang Yinzi (SCOP 1 mg·kg-1·d-1 + Dihuang Yinzi 5.5, 11.0, and 22.0 g·kg-1·d-1, n=10), and donepezil (SCOP 1 mg·kg-1·d-1 + donepezil 0.84 mg·kg-1·d-1, n=10). Mice were administrated with corresponding drugs for 6 weeks. Modeling started in the 4th week, and mice in other groups except the control group were injected with SCOP intraperitoneally 40 min after daily gavage. Behavioral testing began in the 5th week, 30 min after modeling each day. The Morris water maze and novel object recognition tests were carried out to evaluate the spatial learning and memory function of mice. Nissl staining was employed to observe the survival of neurons and Nissl bodies in the hippocampal CA1 region. Western blot was employed to determine the protein levels of silent information regulator 2 (SIRT2), α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor 1 (GluA1), protein kinase A (PKA), cAMP response element-binding protein (CREB), phosphorylated-CREB (p-CREB), postsynaptic density protein 95 (PSD95), growth-associated protein-43 (GAP-43), and synaptophysin (SYN) in the hippocampus. Immunofluorescence was used to detect the expression of doublecortin (DCX) in the hippocampal dentate gyrus (DG) region. ResultsCompared with the control group, the model group showed impaired learning and memory (P<0.01), obvious neuronal damage in the hippocampal CA1 region, a reduction in neuron survival (P<0.01), a decrease in DCX expression in the hippocampal DG region (P<0.01), down-regulated proteins levels of GluA1, PKA, p-CREB/CREB, PSD95, SYN, and GAP-43 in the hippocampal tissue (P<0.05, P<0.01), and an up-regulated protein level of SIRT2 (P<0.01). Compared with the model group, the medium- and high-dose Dihuang Yinzi groups and the donepezil group showed improvements in learning and memory (P<0.05, P<0.01), while the low-, medium-, and high-dose Dihuang Yinzi groups and the donepezil group had increased neuron survival (P<0.05, P<0.01). The medium-dose Dihuang Yinzi group and the donepezil group showed increased DCX expression (P<0.05, P<0.01). The medium- and high-dose Dihuang Yinzi groups and the donepezil group showed up-regulation in the protein levels of GluA1, PKA, p-CREB/CREB, PSD95, SYN, and GAP-43 (P<0.05, P<0.01) and down-regulation in the protein level of SIRT2 (P<0.01). ConclusionDihuang Yinzi can improve the cognitive function in the mouse model of learning and memory impairments induced by SCOP by inhibiting the upregulation of SIRT2, activating the PKA/CREB signaling pathway, improving synaptic plasticity, and reducing hippocampal neuronal damage.
2.Visualization analysis on research status and hotspots of TCM syndrome differentiation and treatment for headache based on VOSviewer
Xinran ZHAO ; Xinlong LI ; Yu ZHANG ; Wenna LIU ; Xing LYU
International Journal of Traditional Chinese Medicine 2025;47(7):999-1004
Objective:To explore the research status and hotspots of TCM syndrome differentiation and treatment for headache using bibliometrics.Methods:Literature about TCM syndrome differentiation and treatment for headache was retrieved from CNKI, VIP, Wanfang Data, and CBM from the establishment of the databases to July 18, 2024. Excel 2023 was used to extract information such as publication time, author, unit and keywords of the literature. The authors' affiliation and keywords were preprocessed. VOSviewer software was used for keyword co-occurrence analysis and clustering analysis, and a keyword temporal overlay network was constructed.Results:Totally 1 513 articles were finally included. The journal with the largest number of publications was Henan Traditional Chinese Medicine. 346 authors were involved, initially forming research teams represented with Cao Kegang, Zhou Jianwei, Ni Jinjun, etc., mainly from Beijing University of Chinese Medicine, Henan University of Chinese Medicine, Shandong University of Traditional Chinese Medicine, etc.; the included literature included a total of 2 153 keywords, which the frequency of 5 931 times in total. The top three keywords in frequency were acupuncture and moxibustion therapy, clinical efficacy, and experience of famous doctors. Current research hotspots included data mining, network pharmacology, literature research, syndrome elements, medication law, venturing and bloodletting therapy, calcitonin gene-related peptide, classic prescriptions, nitric oxide, etc. Conclusions:At present, research on TCM syndrome differentiation and treatment for headache mainly focuses on three major sections: acupuncture, moxibustion and massage, clinical efficacy of TCM syndrome differentiation and treatment, and experience of famous doctors. Future research mainly focuses on data mining, medication law, network pharmacology, syndrome elements, and pathogenesis.
3.Clinical Observation on Tongyuan Acupuncture in the Treatment of Acute Gouty Arthritis
Lixian LI ; Minjie PAN ; Wenna ZHANG ; Qingxia XIE ; Zhongqi SHEN ; Jiaying XIAO ; Li CHEN
Journal of Guangzhou University of Traditional Chinese Medicine 2025;42(3):676-682
Objective To observe the clinical efficacy of Tongyuan acupuncture in the treatment of acute gouty arthritis.Methods A total of 126 cases of patients with definitive diagnosis of acute gouty arthritis admitted to the wards and outpatient clinics of Guangzhou Nansha District Hospital of Traditional Chinese Medicine from November 2023 to June 2024 were selected as the study subjects.The patients were randomly divided into observation group and control group according to the random number table method,with 63 cases in each group.The control group was given health training and conventional treatment,while the observation group was given Tongyuan acupuncture on the basis of treatment in the control group.Patients in both groups were treated for 14 consecutive days.After two weeks of treatment,the clinical efficacy of the two groups was evaluated.The changes in the clinical symptom scores,the Visual Analogue Scale(VAS)scores of pain,the levels of musculoskeletal ultrasonography(synovial proliferation,blood flow signals,and joint fluid)before and after the treatment were observed in patients of both groups.The changes of blood uric acid(UA),erythrocyte sedimentation rate(ESR),C-reactive protein(CRP),tumor necrosis factor α(TNF-α),and interleukin 1(IL-1)before and after treatment were compared between the two groups.Results(1)The total effective rate was 95.24%(60/63)in the observation group and 84.13%(53/63)in the control group.The efficacy of the observation group was superior to that of the control group,the difference being statistically significant(P<0.05).(2)After treatment,the clinical symptom scores and VAS scores of the patients in the two groups were improved significantly(P<0.05),and the improvement in the observation group was significantly superior to that in the control group,the difference being statistically significant(P<0.05).(3)After treatment,the serum UA,ESR,and CRP levels of patients in the two groups were improved significantly(P<0.05),and the improvement in the observation group was significantly superior to that in the control group,the difference being statistically significant(P<0.05).(4)After treatment,the TNF-α and IL-1 levels of patients in the two groups were improved significantly(P<0.05),and the improvement in the observation group was significantly superior to that in the control group,the difference being statistically significant(P<0.05).(5)After treatment,the musculoskeletal ultrasound indicators of the two groups of patients were improved significantly(P<0.05),and the improvement in the observation group was significantly superior to that in the control group,the difference being statistically significant(P<0.05).Conclusion Tongyuan acupuncture in the treatment of acute gouty arthritis can significantly improve the clinical symptoms of patients,reduce the level of patients'blood UA and inflammatory factor.
4.Effects of astragaloside IV on acute myocardial injury in rats with high-level spinal cord injury
Qinfeng HUANG ; Ying ZHENG ; Liqin WEI ; Ye LIAO ; Jiaqi LI ; Lijun LIN ; Jiaxin CHEN ; Rujie ZHENG ; Wenna LIN ; Hui CHEN
Chinese Journal of Trauma 2024;40(11):1028-1039
Objective:To investigate the effects of astragaloside IV (AS-IV) on acute myocardial injury in rats with high-level spinal cord injury (SCI).Methods:Twenty-four healthy male SD rats, aged 8-10 weeks with a body weight of 250-300 g, were randomly divided into 4 groups using a random number table method: sham operation group, high-level SCI group (SCI group), high-level SCI+AS-IV group (SCI+AS-IV group) and high-level SCI+AS-IV+silent information regulator 1 (SIRT1) inhibitor EX527 group (SCI+AS-IV+EX527 group), with 6 rats in each group. The SCI model was established using the modified Allen method and the sham operation group underwent the spinal cord exposure only. In the SCI+AS-IV group, 40 mg/kg of AS-IV was injected intraperitoneally immediately after injury. SCI+AS-IV+EX527 group received an intraperitoneal injection of 5 mg/kg EX527 at one hour before injury and another injection of 40 mg/kg AS-IV in the same way immediately after injury. The sham operation group and the SCI group received an equal volume of saline via intraperitoneal injection. Immediately after awakening from injury, the hind limb motor function of the rats in each group was observed, recorded and then evaluated using the BBB method. At 24 hours after injury, the ultrastructure of the cardiomyocytes was examined under a transmission electron microscope; the levels of serum cardiac troponin I (cTnI), myocardial tissue inflammatory factors interleukin (IL)-18 and IL-1β were quantified by the ELISA method; the level of reactive oxygen species (ROS) of the myocardial tissue was assessed utilizing the dihydroethidium (DHE) assay; biochemical analyses were employed to determine the superoxide dismutase (SOD) activity and malondialdehyde (MDA) concentrations; mRNA and protein expression levels of nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3), cysteinyl aspartate specific proteinase-1 (caspase-1), gasdermin D (GSDMD), SIRT1 and peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) were examined using RT-PCR and Western blot; cardiomyocyte pyroptosis rate was evaluated by caspase-1 and TUNEL double-labeled fluorescence staining.Results:Immediately after awakening from injury, the sham operation group exhibited normal hind limb activity, with BBB scores of 21(21, 21)points, while the remaining groups displayed flaccid paralysis in both hind limbs, accompanied by the cessation of spontaneous excretion, with BBB scores of 0(0, 0)points. At 24 hours after injury, transmission electron microscopy did not reveal any significant abnormalities in the ultrastructure of the myocardiomyocytes in the sham operation group, while changes of varying degrees were observed in the SCI group. The ELISA results indicated that at 24 hours after injury, the serum cTnI level in the SCI group was (1 435.3±148.1)pg/ml, higher than (619.6±95.4)pg/ml in the sham operation group ( P<0.01); the cTnI level was (1 154.0±80.0)pg/ml in the SCI+AS-IV group, lower than that in the SCI group ( P<0.01); the cTnI level was (1 321.8±50.2)pg/ml in the SCI+AS-IV+EX527 group, higher than that in the SCI+AS-IV group ( P<0.05). The levels of IL-18 and IL-1β in the myocardial tissue in the SCI group were (493.0±145.0)pg/ml and (936.7±93.2)pg/ml, higher than (131.1±62.5)pg/ml and (281.7±83.6)pg/ml in the sham operation group ( P<0.01); the levels of IL-18 and IL-1β in the SCI+AS-IV group were (182.4±45.6)pg/ml and (573.4±99.5)pg/ml, lower than those in the SCI group ( P<0.01); the levels of IL-18 and IL-1β in the SCI+AS-IV+EX527 group were (337.4±72.0)pg/ml and (742.6±82.7)pg/ml, higher than those in the SCI+AS-IV group ( P<0.05), yet lower than those in the SCI group ( P<0.01). At 24 hours after injury, DHE and biochemical assays showed that the levels of ROS and MDA in the myocardial tissue in the SCI group were (65±6)% and (1.97±0.27)nmol/mg, higher than (19±10)% and (1.03±0.16)nmol/mg in the sham operation group ( P<0.01); the ROS and MDA levels in the SCI+AS-IV group were (37±10)% and (1.39±0.11)nmol/mg, lower than those in the SCI group ( P<0.01); the ROS and MDA levels in the SCI+AS-IV+EX527 group were (52±7)% and (1.70±0.14)nmol/mg, higher than those in the SCI+AS-IV group ( P<0.05). The SOD level in the myocardial tissue of the SCI group was (658.48±77.56)U/mg, lower than (1 059.55±71.91)U/mg in the sham operation group ( P<0.01); the SOD level in the SCI+AS-IV group was (901.74±32.30)U/mg, higher than that in the SCI group ( P<0.01); the SOD level in the myocardial tissue in the SCI+AS-IV+EX527 group was (799.86±26.70)U/mg, lower than that in the SCI+AS-IV group ( P<0.05). At 24 hours after injury, RT-PCR showed that the mRNA expression levels of NLRP3, caspase-1 and GSDMD in the myocardial tissue of the SCI group were 2.07±0.25, 2.46±0.28 and 1.82±0.12 respectively, which were higher than 1.10±0.13, 0.95±0.17 and 1.03±0.08 in the sham operation group ( P<0.01); the mRNA expression levels of NLRP3, caspase-1 and GSDMD in the SCI+AS-IV group were 1.47±0.24, 1.51±0.16 and 1.42±0.13 respectively, which were lower than those in the SCI group ( P<0.01); the mRNA expression levels of NLRP3, caspase-1 and GSDMD in the SCI+AS-IV+EX527 group were 1.93±0.28, 1.97±0.31 and 1.65±0.16 respectively, which were higher than those in the SCI+AS-IV group, yet lower than those in the SCI group ( P<0.05). The mRNA expression levels of SIRT1 and PGC-1α in the myocardial tissue in the SCI group were 0.41±0.09 and 0.56±0.07, lower than 1.20±0.14 and 1.29±0.20 in the sham operation group ( P<0.01); the mRNA expression levels of SIRT1 and PGC-1α in the myocardial tissue in the SCI+AS-IV group were 0.78±0.08 and 1.01±0.19, higher than those of the SCI group ( P<0.01); the mRNA expression levels of SIRT1 and PGC-1α in the myocardial tissue of the SCI+AS-IV+EX527 group were 0.53±0.12 and 0.72±0.22, lower than those of the SCI+AS-IV group ( P<0.05). At 24 hours after injury, the western blot analysis showed that the protein expression levels of NLRP3, caspase-1 and GSDMD in the myocardial tissue in the SCI group were 1.00±0.20, 0.60±0.19 and 0.77±0.15 respectively, which were higher than 0.27±0.09, 0.18±0.10 and 0.28±0.08 in the sham operation group ( P<0.01); the protein expression levels of NLRP3, caspase-1 and GSDMD in the SCI+AS-IV group were 0.59±0.10, 0.25±0.11 and 0.33±0.11 respectively, lower than those in the SCI group ( P<0.01); the protein expression levels of NLRP3, caspase-1 and GSDMD in the myocardial tissue in the SCI+AS-IV+EX527 group were 0.85±0.15, 0.54±0.12 and 0.55±0.13 respectively, higher than those in the SCI+AS-IV group ( P<0.05). The protein expression levels of SIRT1 and PGC-1α in the myocardial tissue in the SCI group were 0.44±0.16 and 0.28±0.10, lower than 0.93±0.22 and 0.75±0.16 in the sham operation group ( P<0.01); the protein expression levels of SIRT1 and PGC-1α in the myocardial tissue in the SCI+AS-IV group were 0.78±0.19 and 0.55±0.12, higher than those in the SCI group ( P<0.01); the protein expression levels of SIRT1 and PGC-1α in the myocardial tissue in the SCI+AS-IV+EX527 group were 0.46±0.16 and 0.35±0.07, lower than those in the SCI+AS-IV group ( P<0.05). At 24 hours after injury, caspase-1 and TUNEL double-labeled fluorescence staining showed that the cardiomyocyte pyroptosis rate in the SCI group was (34.5±6.7)%, higher than (5.3±2.9)% in the sham operation group ( P<0.01); the cardiomyocyte pyroptosis rate in the SCI+AS-IV group was (13.4±3.0)%, lower than that in the SCI group ( P<0.01); the cardiomyocyte pyroptosis rate in the SCI+AS-IV+EX527 group was (22.5±5.9)%, higher than that in the SCI+AS-IV group ( P<0.01), yet lower than that in the SCI group ( P<0.01). Conclusions:AS-IV can significantly reduce acute myocardial injury in rats with high-level SCI. Its mechanism may involve activating the myocardial SIRT1/PGC-1α signaling pathway, protecting the mitochondria, enhancing the ability to resist oxidative stress, and effectively inhibiting the NLRP3 inflammasome-mediated pyroptosis pathway.
5.Pathogenic characteristics of viral diarrhea in children under five years of age in sentinel surveillance in Lulong County of Hebei Province, 2010-2020
Wenna ZHAO ; Tong SU ; Yingying LIU ; Qiuli YU ; Yun XIE ; Qi LI
Chinese Journal of Epidemiology 2024;45(3):347-352
Objective:To analyze pathogenic characteristics of viral diarrhea in children aged <5 years in Hebei Province and provide reference for the prevention and control of viral diarrhea in children.Methods:Stool samples were collected from in-patients with diarrhea under five years old from sentinel hospitals in Lulong County of Hebei between 2010 and 2020. ELISA detected rotavirus antigen, and then positive samples were genotyped by semi nested reverse transcription PCR of two rounds. Calicivirus, genotyping astrovirus, and adenovirus were detected by real-time fluorescence quantification PCR. The data were analyzed by using software SPSS 20.0.Results:In 2 925 detected stool samples, 1 919 (65.61%) were positive. The positive rates of rotavirus, calicivirus, adenovirus, and astrovirus were 42.80% (1 252/2 925), 22.12% (647/2 925), 6.19% (181/2 925), 3.56% (104/2 925). Viral diarrhea was mainly caused by rotavirus infection, accounting for 59.30% (1 017/1 715) between 2010 and 2017, and by calicivirus infection accounting for 53.43% (109/204) between 2018 and 2020. The peak positive rate of rotavirus occurred in winter, with the highest rate in infants aged 12 to 17 months (52.96%,483/912). In the rotavirus positive samples, G9P[8] was mainly detected strains (58.31%,730/1 252), followed by G3P[8] (8.15%,102/1 252). The calicivirus-positive samples were mainly infected with norovirus GⅡ. Sequence analysis indicated that the main type was GⅡ.4 [P31] between 2011 and 2016 and GⅡ.3 [P12] in 2018.Conclusions:Rotavirus and calicivirus were the main pathogens causing infant diarrhea in children under five years old in Hebei from 2010 to 2020. Winter was the main epidemic season.
6.Progress in the Application of Non-cell-based Permeation Model in the Study of the Permeability of BSC Class Ⅱ Drugs
Wenna WU ; Li DING ; Zhongliang FENG ; Xiaoming HE ; Chaoxing HE ; Yu FANG
Chinese Journal of Modern Applied Pharmacy 2024;41(8):1135-1141
Permeability is one of the determinants of intestinal absorption and oral bioavailability. The non-cell-based permeation model is a kind of in vitro permeability measurement tool, which has the advantages of high efficiency, low cost, stable property, easy to use and customizable. According to the barrier type, non-cell-based permeation model can be divided into biomimetic barriers containing (phosphate) lipids and non-biomimetic barriers without lipids. Biomimetic permeation models include parallel artificial membrane permeability assay, vesicle-based permeation assay and PermeaPad®. Non biomimetic permeation models include Hollow fiber membrane models based on polyether sulfone materials. In foreign countries, the application of these four barriers for different purposes is gradually becoming a hot spot in drug absorption research. However, in China, there are only more applied studies on PMAPM and few published applied studies on the other three barriers. In order to meet the development needs of insoluble drug formulations, the author summarized the permeability devices and permeability calculation methods, searched the application of non-cell-based permeation model in the permeability of BSCⅡ drugs in recent years, and summarized the characteristic applications of three Biomimetic permeation models and hollow fiber membranes.
7.Preparation and application of PRRSV MS2 armored virus-like particles qualityas control products
Jiamin HE ; Xuanfei PANG ; Lyu LUO ; Jiazhen YANG ; Baozhen ZHANG ; Jianmin WU ; Wenna LIU ; Zhongsheng LI ; Yiquan BAI
Chinese Journal of Veterinary Science 2024;44(11):2316-2323
In order to develop a positive quality control products for the detection of porcine repro-ductive and respiratory syndrome virus(PRRSV)nucleic acid by real-time fluorescent quantitative PCR(RT-qPCR),the positive quality control products of PRRSV-1 and PRRSV-2 M genes were prepared using armored RNA technology of MS2 phage.PRRSV-1 and PRRSV-2 M genes were amplified,purified and recovered,and ligated into pET28b vector containing MS2 mature enzyme protein gene and capsid protein.After transformed into BL21(DE3),the gene products were in-duced by IPTG and purified by PEG6000 precipitation method to prepare the armored RNA virus-like particles(AR-PRRSV)containing PRRSV M gene.Following the performance evaluation,as the positive quality control products of PRRSV-1 and PRRSV-2 M genes,AR-PRRSV1M and AR-PRRSV2M were calculated using YY/T 1652-2019 standard.Results showed that it had a good u-niformity,stable storage for the armored virus-like particles at-20,4,25 ℃ for 60 d,and 37 ℃ for 30 d.The prepared armored virus-like particles AR-PRRSV1M and AR-PRRSV2M were deter-mined by digital quantitative PCR(ddPCR)after preliminary quantification by RT-qPCR.The 104 copies/μL of AR-PRRSV1M and AR-PRRSV2M ddPCR fixation was(1.33+0.50)× 104 cop-ies/μL.The above results indicates that the AR-PRRSVM can be used as the quality control of the whole detection process(nucleic acid extraction,reverse transcription and RT-qPCR).
8.Latent profile analysis of dyadic mental health literacy among stroke patients and their caregivers
Shirui LI ; Zhenxiang ZHANG ; Wenna WANG ; Yongxia MEI ; Xiaoxuan WANG ; Zhiwei LIU
Chinese Journal of Nursing 2024;59(19):2389-2395
Objective To explore the categories of dyadic mental health literacy among stroke patients and their caregivers,and to analyze the differences in the characteristics of different classes of stroke patients and their caregivers.Methods A convenient sampling method was used to select 287 dyads of stroke patients and their caregivers who were treated at a tertiary general hospital in Henan province from July to October 2020.The general information questionnaire,Multicomponent Mental Health Literacy and Social Support Rating Scale were used for investigation.Latent profile analysis was adopted to explore the categories of dyadic mental health literacy,and multiple logistic regression was used to analyze the influencing factors of each category.Results Stroke patients and their caregivers were divided into 4 categories based on scores of mental health literacy:dyadic low resource group(19.86%),dyadic low literacy group(54.36%),dyadic low belief group(11.15%),dyadic high literacy group(14.63%).The patient's age,average monthly household income,the caregiver's age,the caregiver's Social Support Rating Scale score,the caregiver's educational level,daily care time and total time length of care were the factors influencing the categories of dyadic mental health literacy among stroke patients and their caregivers(P<0.05).Conclusion Stroke patients and their caregivers were divided into 4 categories based on scores of mental health literacy.Medical staff should carry out comprehensive psychological interventions for stroke patients and their caregivers with different dyadic mental health literacy characteristics,so as to improve dyadic mental health literacy.
9.Qualitative research on the practical training objectives of intravenous therapy nurses
Dandan LI ; Yuanjing QIAO ; Xu WANG ; Yuxue XIA ; Wenna LIANG ; Guangya QIN ; Mengxuan FENG
Chinese Journal of Modern Nursing 2023;29(5):600-606
Objective:To discuss the composition and connotation of practical training objectives for nurses specialized in intravenous therapy, and provide guidance and reference for standardizing the practical training of nurses specialized in intravenous therapy.Methods:In this phenomenological analysis in qualitative research, 13 intravenous treatment and nursing experts from Shandong, Zhejiang, Sichuan, and Shaanxi provinces were selected from May to July 2021 for semi-structured interviews. Colaizzi's 7-step method and Nvivo 12.0 were used to organize data and analyze and refine themes.Results:Three themes and 12 subthemes were extracted for the practical training of intravenous therapy nurses, including knowledge objectives, ability objectives, and well-rounded objectives.Conclusions:Attention should be paid to the setting of clinical professional knowledge, skills and comprehensive quality goals for nurses specialized in intravenous therapy, so as to improve the pertinence and timeliness of training, promote the quality of training and the professional development of specialized training for intravenous therapy.
10.Molecular engineering of transketolase from Escherichia coli and tartaric semialdehyde biosynthesis.
Jianfeng WANG ; Wenying LI ; Zhenqi XIN ; Wenna FENG ; Xiaomin SUN ; Jianfeng YUAN
Chinese Journal of Biotechnology 2022;38(12):4615-4629
Transketolase (EC 2.2.1.1, TK) is a thiamine diphosphate-dependent enzyme that catalyzes the transfer of a two-carbon hydroxyacetyl unit with reversible C-C bond cleavage and formation. It is widely used in the production of chemicals, drug precursors, and asymmetric synthesis by cascade enzyme catalysis. In this paper, the activity of transketolase TKTA from Escherichia coli K12 on non-phosphorylated substrates was enhanced through site-directed saturation mutation and combined mutation. On this basis, the synthesis of tartaric semialdehyde was explored. The results showed that the optimal reaction temperature and pH of TKTA_M (R358I/H461S/R520Q) were 32 ℃ and 7.0, respectively. The specific activity on d-glyceraldehyde was (6.57±0.14) U/mg, which was 9.25 times higher than that of the wild type ((0.71±0.02) U/mg). Based on the characterization of TKTA_M, tartaric acid semialdehyde was synthesized with 50 mmol/L 5-keto-d-gluconate and 50 mmol/L non-phosphorylated ethanolaldehyde. The final yield of tartaric acid semialdehyde was 3.71 g with a molar conversion rate of 55.34%. Hence, the results may facilitate the preparation of l-(+)-tartaric acid from biomass, and provide an example for transketolase-catalyzed non-phosphorylated substrates.
Escherichia coli/genetics*
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Transketolase/chemistry*
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Tartrates
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Escherichia coli Proteins/genetics*


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