1.Recombinant expression of Sphingobium yanoikuyae esterase SyEst870 capable of degrading carbamate pesticides.
Xiaoqian XIE ; Yin FENG ; Yuanyuan ZHOU ; Xin YAN ; Xiaoqin YUAN ; Wuxia QIU ; Xinfang MAO ; Zhongyuan LIU
Chinese Journal of Biotechnology 2025;41(4):1605-1620
Carbamate pesticides, a new type of broad-spectrum pesticides for controlling pests, mites, and weeds, are developed to address the shortcomings of organochlorine and organophosphorus pesticides. Their widespread use and slow degradation have led to environmental pollution, causing damage to ecosystems and human health. Managing pesticide residues is a pressing issue in the current environmental protection. This study aims to investigate the expression of SyEst870, a member of the SGNH/GDSL hydrolase family in Sphingobium yanoikuyae, in a prokaryotic system and evaluate the ability of the recombinant protein to degrade carbamate pesticides. The prokaryotic expression vector pET-32a-SyEst870 was constructed and transformed into the Escherichia coli BL21 for heterologous expression. The purified protein was studied in terms of enzyme activity and effects of temperature, pH, and metal ions on the enzyme activity, with p-nitrophenol acetate as the substrate and based on the standard curve of p-nitrophenol. LC-MS (liquid chromatography-mass spectrometry) was employed to examine the degradation effects of SyEst870 on carbaryl, metolcarb, and isoprocarb. GC-MS (gas chromatography-mass spectrometry) was employed to detect the degradation products of SyEst870 for the three pesticides. The soluble protein SyEst870 was successfully obtained through the heterologous expression in Escherichia coli, which yielded an enzyme with the activity of 677.5 U after affinity chromatography. SyEst870 exhibited degradation rates of 82.34%, 84.43%, and 92.87% for carbaryl, metolcarb, and isoprocarb, respectively, at an initial concentration of 100 mg/L within 24 h at 30 ℃ and pH 7.0. The primary degradation products of carbaryl were identified as α-naphthol and methyl isocyanate. Metolcarb was mainly degraded into m-cresol and methyl isocyanate, and isoprocarb was mainly degraded into 2-isopropylphenol and methyl isocyanate. Compared with the half-life of carbamate pesticides in the natural environment, which ranges from a few days to several weeks, the recombinant protein SyEst870 can rapidly eliminate the residues of carbamate pesticides. This study lays a foundation for addressing pesticide residues in the environment and in fruits and vegetables.
Escherichia coli/metabolism*
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Sphingomonadaceae/genetics*
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Recombinant Proteins/metabolism*
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Biodegradation, Environmental
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Esterases/metabolism*
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Pesticides/isolation & purification*
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Carbamates/isolation & purification*
2.Clinical effects of gabapentin combined with hemoperfusion in treating skin itching of patients with maintenance hemodialysis
Yan LYU ; Ruizhi MAO ; Xinfang TANG ; Xiaofei BI ; Yaoyu HUANG
Chongqing Medicine 2025;54(2):452-456,463
Objective To investigate the therapeutic effect of gabapentin combined with hemoperfusion on skin pruritus in the patients on maintenance hemodialysis(MHD).Methods A total of 72 patients with MHD complicating moderate to severe skin itching treated in Lianyungang Municipal Oriental Hospital from January 2023 to March 2024 were selected as the study subjects and divided into the observation group and control group by the random number table method,36 cases in each group.On the basis of symptomatic treat-ment,the control group was given hemodialysis 3 times a week and hemoperfusion twice a month;on the basis of the control group,the observation group orally took 1 gabapentin capsule every night,and the patients in the two groups continued to be treated for 12 weeks.The visual analogue scale(VAS)score,Pittsburgh Sleep Quality Index(PSQI)score,molecular toxin level and calcium and phosphorus metabolism were evaluated be-fore treatment,in 4,12 weeks after treatment respectively,and the occurrence of adverse reactions during treatment in the two groups was observed.Results After 4 weeks and 12 weeks of treatment,the VAS and PSQI scores of the observation group were decreased compared with those before treatment,moreover the scores of the observation group were lower than those of the control group in the same period,and the differ-ences were statistically significant(P<0.05);the VAS and PSQI scores after 4 weeks of treatment in the control group were decreased compared with those before treatment,but the difference was not statistically significant(P>0.05);and the VAS and PSQI scores after 12 weeks of treatment in the control group were decreased compared with before treatment,and the difference was statistically significant(P<0.05).After 4 weeks of treatment,the levels of Scr,BUN and β2-MG in the two groups were decreased compared with those before treatment,but the differences were not statistically significant(P>0.05);after 12 weeks of treatment,the levels of Scr,BUN and β2-MG in the two groups were decreased compared with those before treatment and after 4 weeks of treatment,and the differences were statistically significant(P<0.05),but there was no sta-tistically significant difference between the two groups(P>0.05).After 4 weeks of treatment,there was no statistically significant difference in the levels of blood Ca,P and iPTH between the two groups compared with before treatment(P>0.05);after 12 weeks of treatment,except for blood Ca,the levels of blood P and iPTH in the two groups were decreased compared with those before treatment and in 4 weeks of treatment(P<0.05),and the differences were statistically significant(P<0.05),but there was no statistical difference be-tween the two groups(P>0.05).There were no adverse reactions in the control group,and there were 3 cases of drowsiness,1 case of fatigue and 1 case of dizziness at the beginning of treatment in the observation group.The symptoms were mild without treatment and spontaneously relieved in about 1 week.Conclusion Gabap-entin combined with hemoperfusion could quickly and effectively alleviate the itchy symptoms of skin,improve the sleep quality,reduce the uremic toxin levels,and improve the calcium and phosphorus metabolism in MHD patients,with few adverse reactions,and the patients are easy to tolerate.
3.Comparative Study on Ultra-early and Early Enteral Nutrition Support in Elderly Obese Patients With Severe Acute Pancreatitis
Yueji NING ; Qi PAN ; Boneng MAO ; Guochang CHEN ; Qian LIU ; Xinfang XU
Chinese Journal of Gastroenterology 2017;22(12):744-747
Background:Early administration of enteral nutrition can improve intestinal mucosal barrier in patients with severe acute pancreatitis (SAP),reduce infection and complications;but when should the enteral nutrition be started is still controversial. Aims:To study the effect of different initiation time of enteral nutrition on elderly obese patients with SAP. Methods:The clinical efficacy,hospitalization time,hospitalization cost and the risk of complication were analyzed retrospectively in the two groups of patients with either ultra-early enteral nutrition (group A)or early enteral nutrition (group B),as well as the serum levels of inflammatory cytokines before and after treatment. Results:No significant difference in total effective rate was found between group A and group B (90. 9% vs. 79. 2%,χ2 = 1. 227,P > 0. 05). Compared with group B,the recovery time of blood and urine amylase,and hospitalization time in group A were significantly shortened and the cost of hospitalization was significantly decreased (P < 0. 05). The time of abdominal pain, bloating,vomiting and fever in group A was significantly shorter than that in group B (P < 0. 05). After 14 days of treatment,levels of IL-6,TNF-α and CRP in group A were significantly lower than those in group B (P < 0. 05). The incidence of infection was significantly lower in group A than in group B (P < 0. 05). Conclusions:Compared with early enteral nutrition group,ultra-early enteral nutrition for elderly obese patients with SAP has better efficacy,and has a shorter hospital stay and lower hospitalization cost.
4.Expression optimization and characterization of Tenebrio molitor antimicrobiol peptides TmAMP1m in Escherichia coli.
Reyihanguli ALIMU ; Xinfang MAO ; Zhongyuan LIU
Chinese Journal of Biotechnology 2013;29(6):836-847
To improve the expression level of tmAMP1m gene from Tenebrio molitor in Escherichia coli, we studied the effects of expression level and activity of the fusion protein HIS-TmAMP1m by conditions, such as culture temperature, inducing time and the final concentration of inductor Isopropyl beta-D-thiogalactopyranoside (IPTG). We analyzed the optimum expression conditions by Tricine-SDS-PAGE electrophoresis, meanwhile, detected its antibacterial activity by using agarose cavity diffusion method. The results suggest that when inducing the recombinant plasmid with a final IPTG concentration of 0.1 mmol/L at 37 degrees C for 4 h, there was the highest expression level of fusion protein HIS-TmAMP1m in Escherichia coli. Under these conditions, the expression of fusion protein accounted for 40% of the total cell lysate with the best antibacterial activity. We purified the fusion protein HIS-TmAMPlm with nickel-nitrilotriacetic acid (Ni-NTA) metal-affinity chromatography matrices. Western blotting analysis indicates that the His monoclonal antibody could be specifically bound to fusion protein HIS-TmAMPlm. After expression by inducing, the fusion protein could inhibit the growth of host cell transformed by pET30a-tmAMP1m. The fusion protein HIS-TmAMP1m had better stability and remained higher antibacterial activities when incubated at 100 degrees C for 10 h, repeated freeze thawing at -20 degrees C, dissolved in strong acid and alkali, or treated by organic solvents and protease. Moreover, the minimum inhibitory concentration results demonstrated that the fusion protein HIS-TmAMP1m has a good antibacterial activity against Staphylococcus aureus, Staphylococcus sp., Corynebacterium glutamicum, Bacillus thuringiensis, Corynebacterium sp. This study laid the foundation to promote the application of insect antimicrobial peptides and further research.
Animals
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Anti-Infective Agents
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pharmacology
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Antimicrobial Cationic Peptides
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biosynthesis
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genetics
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pharmacology
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Escherichia coli
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genetics
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metabolism
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Genetic Vectors
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genetics
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Insect Proteins
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biosynthesis
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genetics
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Recombinant Fusion Proteins
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biosynthesis
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genetics
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pharmacology
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Tenebrio
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chemistry

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