Martentoxin, a 4,046 Da polypeptide toxin purified from the venom of the scorpion Buthus martensii Karsch, has been demonstrated to block large-conductance Ca2＋-activated K＋ （BKca） channels; however, its biologica...Martentoxin, a 4,046 Da polypeptide toxin purified from the venom of the scorpion Buthus martensii Karsch, has been demonstrated to block large-conductance Ca2＋-activated K＋ （BKca） channels; however, its biological roles are still largely unknown. In the present study, we investigated the pharmacological effects of martentoxin on regulating the production of nitric oxide induced by TNF-a in human umbilical vein endothelial cells （HU- VECs）. We found that, 1, 10 and 100 ~tmol/L martentoxin decreased nitric oxide production by HUVECs ex- posed to 10 ng/mL TNF for 6, 12 and 24 hours. We further demonstrated that martentoxin inhibited the activity of iNOS and retarded the down-regulation of eNOS mRNA induced by TNF-a. Therefore, martentoxin could be a potential therapeutic agent for vascular diseases.展开更多
BACKGROUND： Buthus martensii Karsch is a rare medicinal animal, and dried integral Buthus rnartensii Karsch is an important drug in traditional Chinese medicine. OBJECTIVE： To investigate the effects of scorpion ven...BACKGROUND： Buthus martensii Karsch is a rare medicinal animal, and dried integral Buthus rnartensii Karsch is an important drug in traditional Chinese medicine. OBJECTIVE： To investigate the effects of scorpion venom analgesic active peptide （SAP） extracted from Buthus martensii Karsch on evoked unit discharge of the common peroneal nerve in the posterior nucleus group of the thalamus using a stereotaxic electrophysiological extracellular microelectrode recording. DESIGN, TIME AND SETTING： One-way designed study, performed in the Physiological Laboratory of Shenyang Medical College on September 15, 2006. MATERIALS： Fifty 3-4 months old Wistar rats （25 males and 25 females） were used. SAP was provided by Shenyang Pharmaceutical University. Morphine solution was made by the First Drug Manufactory, Northeastern Drug Manufacture Group （batch number： H20013351）. Naloxone solution was made by Hunan Pharmaceutical Co., Ltd. （batch number： H43021669）. Type ATAC-350 medical data processing equipment was made by the Photoelectricity Company, Japan. METHODS： Fifty rats were randomly divided into the SAP group （n=20）, saline group （n=10）, morphine group （n=10）, or naloxone group （n=10）. In the SAP group, the common peroneal nerve was separated and stimulated with a single square wave （17-19 V intensity; 0.2 ms width; 20 ms retardation time）. Subsequently, SAP （0.01%, 2 μL） was injected into the posterior nucleus group of the thalamus. Rats in the naloxone group were injected with naloxone （1.0 mg/kg i.v.） before SAP injection. Rats in the saline group and the morphine group were injected with saline （2 μL） or morphine （0.01%, 2μL）, respectively, before SAP injection. Other procedures were the same as those in the SAP group. MAIN OUTCOME MEASURES： Evoked discharge in the posterior nucleus group of the thalamus and effects of SAP alone and SAP in combination with saline, morphine, or naloxone on discharges in the posterior nucleus group of the thalamus as 展开更多
The crystal structure of an acidic neurotoxin, BmK M8, from Chinese scorpion Buthus martensii Karsch was determined at 0.25 nm resolution. The X-ray diffraction data of BmK M8 crystals at 0.25nm resolution were collec...The crystal structure of an acidic neurotoxin, BmK M8, from Chinese scorpion Buthus martensii Karsch was determined at 0.25 nm resolution. The X-ray diffraction data of BmK M8 crystals at 0.25nm resolution were collected on a Siemens area detector. Using molecular replacement method with a basic scorpion toxin AaH II in a search model, the cross-rotation function, PC-refinement and translation function were calculated by X-PLOR program package. The correct orientation and position of BmK M8 molecule in crystal were determined in a resolution range of 1.5 - 0.35nm, The oystallographic refinement was further performed by stereo-chemical restrict least-square technique, followed by simulated annealing, slow-cooling protocols. The final crystallographic R-factor at 0.8-0.25 nm is 0.171. The standard deviations of bond length and bond angle from ideality are 0.001 7nm and 2.24° , respectively. The final model of BmK M8 structure is composed of a dense core of secondary structure elements by a stretch of α-helix with two and a half turns (residues 19-28) and a three-stranded antiparallel β-sheet (residues 2-4, 32 - 37, 45- 51). In addition, three loops protruded from the structural core. The general folding properties of BmK M8 molecule were described; a common structure motif which may appear in all scorpion neurotoxins was identified. The conserved aromatic residues and charged residues were found to be distributed on two roughly opposite surfaces of the molecule. The relationship between these two faces and receptor-binding sites are also discussed.展开更多
基金supported by the National Science Foundation of China(No.30271137No.30771831+1 种基金No.81072329)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘Martentoxin, a 4,046 Da polypeptide toxin purified from the venom of the scorpion Buthus martensii Karsch, has been demonstrated to block large-conductance Ca2＋-activated K＋ （BKca） channels; however, its biological roles are still largely unknown. In the present study, we investigated the pharmacological effects of martentoxin on regulating the production of nitric oxide induced by TNF-a in human umbilical vein endothelial cells （HU- VECs）. We found that, 1, 10 and 100 ~tmol/L martentoxin decreased nitric oxide production by HUVECs ex- posed to 10 ng/mL TNF for 6, 12 and 24 hours. We further demonstrated that martentoxin inhibited the activity of iNOS and retarded the down-regulation of eNOS mRNA induced by TNF-a. Therefore, martentoxin could be a potential therapeutic agent for vascular diseases.
文摘BACKGROUND： Buthus martensii Karsch is a rare medicinal animal, and dried integral Buthus rnartensii Karsch is an important drug in traditional Chinese medicine. OBJECTIVE： To investigate the effects of scorpion venom analgesic active peptide （SAP） extracted from Buthus martensii Karsch on evoked unit discharge of the common peroneal nerve in the posterior nucleus group of the thalamus using a stereotaxic electrophysiological extracellular microelectrode recording. DESIGN, TIME AND SETTING： One-way designed study, performed in the Physiological Laboratory of Shenyang Medical College on September 15, 2006. MATERIALS： Fifty 3-4 months old Wistar rats （25 males and 25 females） were used. SAP was provided by Shenyang Pharmaceutical University. Morphine solution was made by the First Drug Manufactory, Northeastern Drug Manufacture Group （batch number： H20013351）. Naloxone solution was made by Hunan Pharmaceutical Co., Ltd. （batch number： H43021669）. Type ATAC-350 medical data processing equipment was made by the Photoelectricity Company, Japan. METHODS： Fifty rats were randomly divided into the SAP group （n=20）, saline group （n=10）, morphine group （n=10）, or naloxone group （n=10）. In the SAP group, the common peroneal nerve was separated and stimulated with a single square wave （17-19 V intensity; 0.2 ms width; 20 ms retardation time）. Subsequently, SAP （0.01%, 2 μL） was injected into the posterior nucleus group of the thalamus. Rats in the naloxone group were injected with naloxone （1.0 mg/kg i.v.） before SAP injection. Rats in the saline group and the morphine group were injected with saline （2 μL） or morphine （0.01%, 2μL）, respectively, before SAP injection. Other procedures were the same as those in the SAP group. MAIN OUTCOME MEASURES： Evoked discharge in the posterior nucleus group of the thalamus and effects of SAP alone and SAP in combination with saline, morphine, or naloxone on discharges in the posterior nucleus group of the thalamus as
基金Project supported by the National Natural Science Foundation of China.
文摘The crystal structure of an acidic neurotoxin, BmK M8, from Chinese scorpion Buthus martensii Karsch was determined at 0.25 nm resolution. The X-ray diffraction data of BmK M8 crystals at 0.25nm resolution were collected on a Siemens area detector. Using molecular replacement method with a basic scorpion toxin AaH II in a search model, the cross-rotation function, PC-refinement and translation function were calculated by X-PLOR program package. The correct orientation and position of BmK M8 molecule in crystal were determined in a resolution range of 1.5 - 0.35nm, The oystallographic refinement was further performed by stereo-chemical restrict least-square technique, followed by simulated annealing, slow-cooling protocols. The final crystallographic R-factor at 0.8-0.25 nm is 0.171. The standard deviations of bond length and bond angle from ideality are 0.001 7nm and 2.24° , respectively. The final model of BmK M8 structure is composed of a dense core of secondary structure elements by a stretch of α-helix with two and a half turns (residues 19-28) and a three-stranded antiparallel β-sheet (residues 2-4, 32 - 37, 45- 51). In addition, three loops protruded from the structural core. The general folding properties of BmK M8 molecule were described; a common structure motif which may appear in all scorpion neurotoxins was identified. The conserved aromatic residues and charged residues were found to be distributed on two roughly opposite surfaces of the molecule. The relationship between these two faces and receptor-binding sites are also discussed.
