OBJECTIVES: To isolate potassium ion channel Kv4.1 inhibitor from centipede venom, and to determine its primary and spatial structure. METHODS: Ion-exchange chromatography and reversed-phase high-performance liquid chromatography were performed to separate and purify peptide components of centipede venom, and their inhibiting effect on Kv4.1 channel was determined by whole-cell patch clamp recording. The molecular weight of isolated peptide Kv4.1 channel inhibitor was identified with MALDI-TOF, its primary sequence was determined by Edman degradation sequencing and two-dimensional mass spectrometry, its patial structure was established based on iterative thread assembly refinement online analysis. RESULTS: A peptide SsTx-P2 was separated from centipede venom with the molecular weight of 6122.8, and its primary sequence consists of 53 amino acid residues, showed as NH₂-ELTWDFVRTCCKLFPDKSECTKACATEFTGGDESRLKDVWPRKLRSGDSRLKD-OH. Peptide SsTx-P2 potently inhibited the current of Kv4.1 channel transiently transfected in HEK293 cell, with 1.0 μmol/L SsTx-P2 suppressing 95% current of Kv4.1 channel. Its spatial structure showed that SsTx-P2 shared a conserved helical structure. CONCLUSIONS The study has isolated a novel peptide SsTx-P2 from centipede venom, which can potently inhibit the potassium ion channel Kv4.1, and its spatial structure displays a certain degree of conservation.

Objective To explore the neuroprotective effect of coenzyme Q10 and its possible mechanism in mice with chronic restraint stress(CRS).Methods Mouse models of CRS were treated with intraperitoneal injections of coenzyme Q10 at low,moderate and high doses(50,100 and 200 mg/kg,respectively,n=8),VX765(a caspase-1 specific inhibitor,50 mg/kg,n=8),or fluoxetine(10 mg/kg,n=8)on a daily basis for 4 weeks,and the changes in depression-like behaviors of the mice were assessed by sugar water preference test,forced swimming test and tail suspension test.The expression of glial fibrillary acidic protein(GFAP)in the hippocampus of the mice was detected using immunohistochemistry,and the number of synaptic spines was determined with Golgi staining.Western blotting was performed to detect the changes in the expressions of GFAP and pyroptosis-related proteins in the hippocampus,and the colocalization of neurons and caspase-1 p10 was examined with immunofluorescence assay.Results Compared with the normal control mice,the mouse models of CRS showed significantly reduced sugar water preference and increased immobility time in forced swimming and tail suspension tests(P<0.05),and these depression-like behaviors were obviously improved by treatment with coenzyme Q10,VX765 or FLX.The mouse models showed a significantly decreased positive rate of GFAP and lowered GFAP protein expression in the hippocampus with obviously decreased synaptic spines,enhanced expressions of GSDMD-N,caspase-1 and IL-1β,and increased colocalization of neurons and caspase-1 p10(all P<0.05).All these changes were significantly ameliorated in the mouse models after treatment with Q10.Conclusion Coenzyme Q10 can alleviate depression-like behaviors in mice with CRS by down-regulating the pyroptosis signaling pathway.

Objective To propose a CT truncated data reconstruction model(DDTrans)based on projection and image dual-domain Transformer coupled feature learning for reducing truncation artifacts and image structure distortion caused by insufficient field of view(FOV)in CT scanning.Methods Transformer was adopted to build projection domain and image domain restoration models,and the long-range dependency modeling capability of the Transformer attention module was used to capture global structural features to restore the projection data information and enhance the reconstructed images.We constructed a differentiable Radon back-projection operator layer between the projection domain and image domain networks to enable end-to-end training of DDTrans.Projection consistency loss was introduced to constrain the image forward-projection results to further improve the accuracy of image reconstruction.Results The experimental results with Mayo simulation data showed that for both partial truncation and interior scanning data,the proposed DDTrans method showed better performance than the comparison algorithms in removing truncation artifacts at the edges and restoring the external information of the FOV.Conclusion The DDTrans method can effectively remove CT truncation artifacts to ensure accurate reconstruction of the data within the FOV and achieve approximate reconstruction of data outside the FOV.

Objective:To isolate a potassium ion channel Kv4.1 inhibitor from centipede venom,and to determine its sequence and structure.Methods:Ion-exchange chromatography and reversed-phase high-performance liquid chromatography were performed to separate and purify peptide components of centipede venom,and their inhibiting effect on Kv4.1 channel was determined by whole-cell patch clamp recording.The molecular weight of isolated peptide Kv4.1 channel inhibitor was identified with matrix assisted laser desorption ionization-time-of-flight mass spectrometry;its primary sequence was determined by Edman degradation sequencing and two-dimensional mass spectrometry;its structure was established based on iterative thread assembly refinement online analysis.Results:A peptide SsTx-P2 was separated from centipede venom with the molecular weight of 6122.8,and its primary sequence consists of 53 amino acid residues NH2-ELTWDFVRTCCKLFPDKSECTKACATEFTGGDESRLKDVWPRKLRSG DSRLKD-OH.Peptide SsTx-P2 potently inhibited the current of Kv4.1 channel transiently transfected in HEK293 cell,with 1.0 μmol/L SsTx-P2 suppressing 95%current of Kv4.1 channel.Its structure showed that SsTx-P2 shared a conserved helical structure.Conclusion:The study has isolated a novel peptide SsTx-P2 from centipede venom,which can potently inhibit the potassium ion channel Kv4.1 and displays structural conservation.

Objective:To isolate a potassium ion channel Kv4.1 inhibitor from centipede venom,and to determine its sequence and structure.Methods:Ion-exchange chromatography and reversed-phase high-performance liquid chromatography were performed to separate and purify peptide components of centipede venom,and their inhibiting effect on Kv4.1 channel was determined by whole-cell patch clamp recording.The molecular weight of isolated peptide Kv4.1 channel inhibitor was identified with matrix assisted laser desorption ionization-time-of-flight mass spectrometry;its primary sequence was determined by Edman degradation sequencing and two-dimensional mass spectrometry;its structure was established based on iterative thread assembly refinement online analysis.Results:A peptide SsTx-P2 was separated from centipede venom with the molecular weight of 6122.8,and its primary sequence consists of 53 amino acid residues NH2-ELTWDFVRTCCKLFPDKSECTKACATEFTGGDESRLKDVWPRKLRSG DSRLKD-OH.Peptide SsTx-P2 potently inhibited the current of Kv4.1 channel transiently transfected in HEK293 cell,with 1.0 μmol/L SsTx-P2 suppressing 95%current of Kv4.1 channel.Its structure showed that SsTx-P2 shared a conserved helical structure.Conclusion:The study has isolated a novel peptide SsTx-P2 from centipede venom,which can potently inhibit the potassium ion channel Kv4.1 and displays structural conservation.

Objective:To isolate a potassium ion channel Kv4.1 inhibitor from centipede venom,and to determine its sequence and structure.Methods:Ion-exchange chromatography and reversed-phase high-performance liquid chromatography were performed to separate and purify peptide components of centipede venom,and their inhibiting effect on Kv4.1 channel was determined by whole-cell patch clamp recording.The molecular weight of isolated peptide Kv4.1 channel inhibitor was identified with matrix assisted laser desorption ionization-time-of-flight mass spectrometry;its primary sequence was determined by Edman degradation sequencing and two-dimensional mass spectrometry;its structure was established based on iterative thread assembly refinement online analysis.Results:A peptide SsTx-P2 was separated from centipede venom with the molecular weight of 6122.8,and its primary sequence consists of 53 amino acid residues NH2-ELTWDFVRTCCKLFPDKSECTKACATEFTGGDESRLKDVWPRKLRSG DSRLKD-OH.Peptide SsTx-P2 potently inhibited the current of Kv4.1 channel transiently transfected in HEK293 cell,with 1.0 μmol/L SsTx-P2 suppressing 95%current of Kv4.1 channel.Its structure showed that SsTx-P2 shared a conserved helical structure.Conclusion:The study has isolated a novel peptide SsTx-P2 from centipede venom,which can potently inhibit the potassium ion channel Kv4.1 and displays structural conservation.

Objective:To isolate a potassium ion channel Kv4.1 inhibitor from centipede venom,and to determine its sequence and structure.Methods:Ion-exchange chromatography and reversed-phase high-performance liquid chromatography were performed to separate and purify peptide components of centipede venom,and their inhibiting effect on Kv4.1 channel was determined by whole-cell patch clamp recording.The molecular weight of isolated peptide Kv4.1 channel inhibitor was identified with matrix assisted laser desorption ionization-time-of-flight mass spectrometry;its primary sequence was determined by Edman degradation sequencing and two-dimensional mass spectrometry;its structure was established based on iterative thread assembly refinement online analysis.Results:A peptide SsTx-P2 was separated from centipede venom with the molecular weight of 6122.8,and its primary sequence consists of 53 amino acid residues NH2-ELTWDFVRTCCKLFPDKSECTKACATEFTGGDESRLKDVWPRKLRSG DSRLKD-OH.Peptide SsTx-P2 potently inhibited the current of Kv4.1 channel transiently transfected in HEK293 cell,with 1.0 μmol/L SsTx-P2 suppressing 95%current of Kv4.1 channel.Its structure showed that SsTx-P2 shared a conserved helical structure.Conclusion:The study has isolated a novel peptide SsTx-P2 from centipede venom,which can potently inhibit the potassium ion channel Kv4.1 and displays structural conservation.

Objective:To isolate a potassium ion channel Kv4.1 inhibitor from centipede venom,and to determine its sequence and structure.Methods:Ion-exchange chromatography and reversed-phase high-performance liquid chromatography were performed to separate and purify peptide components of centipede venom,and their inhibiting effect on Kv4.1 channel was determined by whole-cell patch clamp recording.The molecular weight of isolated peptide Kv4.1 channel inhibitor was identified with matrix assisted laser desorption ionization-time-of-flight mass spectrometry;its primary sequence was determined by Edman degradation sequencing and two-dimensional mass spectrometry;its structure was established based on iterative thread assembly refinement online analysis.Results:A peptide SsTx-P2 was separated from centipede venom with the molecular weight of 6122.8,and its primary sequence consists of 53 amino acid residues NH2-ELTWDFVRTCCKLFPDKSECTKACATEFTGGDESRLKDVWPRKLRSG DSRLKD-OH.Peptide SsTx-P2 potently inhibited the current of Kv4.1 channel transiently transfected in HEK293 cell,with 1.0 μmol/L SsTx-P2 suppressing 95%current of Kv4.1 channel.Its structure showed that SsTx-P2 shared a conserved helical structure.Conclusion:The study has isolated a novel peptide SsTx-P2 from centipede venom,which can potently inhibit the potassium ion channel Kv4.1 and displays structural conservation.

Objective:To isolate a potassium ion channel Kv4.1 inhibitor from centipede venom,and to determine its sequence and structure.Methods:Ion-exchange chromatography and reversed-phase high-performance liquid chromatography were performed to separate and purify peptide components of centipede venom,and their inhibiting effect on Kv4.1 channel was determined by whole-cell patch clamp recording.The molecular weight of isolated peptide Kv4.1 channel inhibitor was identified with matrix assisted laser desorption ionization-time-of-flight mass spectrometry;its primary sequence was determined by Edman degradation sequencing and two-dimensional mass spectrometry;its structure was established based on iterative thread assembly refinement online analysis.Results:A peptide SsTx-P2 was separated from centipede venom with the molecular weight of 6122.8,and its primary sequence consists of 53 amino acid residues NH2-ELTWDFVRTCCKLFPDKSECTKACATEFTGGDESRLKDVWPRKLRSG DSRLKD-OH.Peptide SsTx-P2 potently inhibited the current of Kv4.1 channel transiently transfected in HEK293 cell,with 1.0 μmol/L SsTx-P2 suppressing 95%current of Kv4.1 channel.Its structure showed that SsTx-P2 shared a conserved helical structure.Conclusion:The study has isolated a novel peptide SsTx-P2 from centipede venom,which can potently inhibit the potassium ion channel Kv4.1 and displays structural conservation.

Objective:To isolate a potassium ion channel Kv4.1 inhibitor from centipede venom,and to determine its sequence and structure.Methods:Ion-exchange chromatography and reversed-phase high-performance liquid chromatography were performed to separate and purify peptide components of centipede venom,and their inhibiting effect on Kv4.1 channel was determined by whole-cell patch clamp recording.The molecular weight of isolated peptide Kv4.1 channel inhibitor was identified with matrix assisted laser desorption ionization-time-of-flight mass spectrometry;its primary sequence was determined by Edman degradation sequencing and two-dimensional mass spectrometry;its structure was established based on iterative thread assembly refinement online analysis.Results:A peptide SsTx-P2 was separated from centipede venom with the molecular weight of 6122.8,and its primary sequence consists of 53 amino acid residues NH2-ELTWDFVRTCCKLFPDKSECTKACATEFTGGDESRLKDVWPRKLRSG DSRLKD-OH.Peptide SsTx-P2 potently inhibited the current of Kv4.1 channel transiently transfected in HEK293 cell,with 1.0 μmol/L SsTx-P2 suppressing 95%current of Kv4.1 channel.Its structure showed that SsTx-P2 shared a conserved helical structure.Conclusion:The study has isolated a novel peptide SsTx-P2 from centipede venom,which can potently inhibit the potassium ion channel Kv4.1 and displays structural conservation.