AaeAP1 and AaeAP2: Novel Antimicrobial Peptides from the Venom of the Scorpion,Androctonus aeneas: Structural Characterisation,Molecular Cloning of Biosynthetic Precursor-Encoding cDNAs and Engineering of Analogues with Enhanced Antimicrobial and Anticancer Activities

The main functions of the abundant polypeptide toxins present in scorpion venoms are the debilitation of arthropod prey or defence against predators. These effects are achieved mainly through the blocking of an array of ion channel types within the membranes of excitable cells. However, while these ion channel-blocking toxins are tightly-folded by multiple disulphide bridges between cysteine residues, there are additional groups of peptides in the venoms that are devoid of cysteine residues. These non-disulphide bridged peptides are the subject of much research interest, and among these are peptides that exhibit antimicrobial activity. Here, we describe two novel non-disulphide-bridged antimicrobial peptides that are present in the venom of the North African scorpion, Androctonus aeneas. The cDNAs encoding the biosynthetic precursors of both peptides were cloned from a venom-derived cDNA library using 3''- and 5''-RACE strategies. Both translated precursors contained open-reading frames of 74 amino acid residues, each encoding one copy of a putative novel nonadecapeptide, whose primary structures were FLFSLIPSVIAGLVSAIRN and FLFSLIPSAIAGLVSAIRN, respectively. Both peptides were C-terminally amidated. Synthetic versions of each natural peptide displayed broad-spectrum antimicrobial activities, but were devoid of antiproliferative activity against human cancer cell lines. However, synthetic analogues of each peptide, engineered for enhanced cationicity and amphipathicity, exhibited increases in antimicrobial potency and acquired antiproliferative activity against a range of human cancer cell lines. These data clearly illustrate the potential that natural peptide templates provide towards the design of synthetic analogues for therapeutic exploitation.     

Scorpion Toxin,BmP01, Induces Pain by Targeting TRPV1 Channel

The intense pain induced by scorpion sting is a frequent clinical manifestation. To date, there is no established protocol with significant efficacy to alleviate the pain induced by scorpion envenomation. One of the important reasons is that, little information on pain-inducing compound from scorpion venoms is available. Here, a pain-inducing peptide (BmP01) has been identified and characterized from the venoms of scorpion (Mesobuthus martensii). In an animal model, intraplantar injection of BmP01 in mouse hind paw showed significant acute pain in wild type (WT) mice but not in TRPV1 knock-out (TRPV1 KO) mice during 30 min recording. BmP01 evoked currents in WT dorsal root ganglion (DRG) neurons but had no effect on DRG neurons of TRPV1 KO mice. Furthermore, BmP01 evoked currents on TRPV1-expressed HEK293T cells, but not on HEK293T cells without TRPV1. These results suggest that (1) BmP01 is one of the pain-inducing agents in scorpion venoms; and (2) BmP01 induces pain by acting on TRPV1. To our knowledge, this is the first report about a scorpion toxin that produces pain by targeting TRPV1. Identification of a pain-inducing compound may facilitate treating pain induced by scorpion envenomation.     

Inhibition Effects of Scorpion Venom Extracts (Buthus Matensii Karsch) on the Growth of Human Breast Cancer MCF-7 Cells

Background

To observe the inhibition effects of the Buthus matensii Karsch (BmK) scorpion venom extracts on the growth of human breast cancer MCF-7 cells, and to explore its mechanisms.

Methods

Two common tumor cells (SMMC7721, MCF-7) were examined for the one which wasmore sensitivity to scorpion venom by MTT method. Cell cycle was determined by flow cytometry. Immunocytochemistry was applied to detect apoptosis-related protein Caspase-3 and Bcl-2 levels, while the expression of cell cycle-related protein Cyclin D1 was shown by Western blotting.

Results

Our data indicated that MCF-7 was the more sensitive cell line to scorpion venom. The extracts of scorpion venom could inhibit the growth and proliferation of MCF-7 cells. Furthermore, the extract of scorpion venom induced apoptosis through Caspase-3 up-regulation while Bcl-2 down-regulation in MCF-7 cells. In addition, the extracts of scorpion venom blocked the cells from G₀/G₁ phase to S phase and decreased cell cycle-related protein Cyclin D1 level after drug intervention compared with the negative control group.

Conclusions

These results showed that the BmK scorpion venom extracts could inhibit the growth of MCF-7 cells by inducing apoptosis and blocking cell cycle in G₀/G₁ phase. The BmK scorpion venom extracts will be very valuable for the treatment of breast cancer.     

全蝎抗凝活性成分的定性分析

目的鉴定与探讨全蝎抗凝活性成分。方法用不同的展开剂，采用薄层色谱法和纸层析法对全蝎抗凝活性成分进行鉴定和分析。结果全蝎抗凝活性成分中不含生物碱、糖类、甾体和萜类，含蛋白质和多肽，但在氨基酸的定性检测中，分离得到6个成分的斑点，与14种氨基酸对照品在相同位置上有相同颜色的斑点。结论全蝎抗凝活性成分中含有多种氨基酸、蛋白质和多肽。     

蝎毒注射液镇痛效果及安全性临床评价

目的：评价蝎毒注射液的镇痛效果和不良反应。方法：多中心随机双盲平行对照试验和开放试验，对照药丁丙诺啡、曲马多和安慰剂，用于手术后疼痛、神经疼痛和癌症疼痛等中度疼痛患者。全部试验完成466例，其中试验药315例，对照药151例。试验分组为单次给药、3d给药和1－2周给药、3d给药和1－2周给药，每次剂量为10－20μg。结果：蝎毒具有确切的镇痛效果，镇痛强度中等偏下。注射后15－30min起效，达峰时间2h 左右，持续时间4-6h。不良反应有头晕、胃不适、恶心、便秘和皮肤搔痒等，发生率很低；对呼吸、血压、心率无影响，对肝肾功能无影响。结论：蝎毒注射液是控制中度疼痛的安全有效的药物。     

A clinical and neurophysiological study of scorpion envenomation in Assiut, Upper Egypt

Scorpion envenomation (SE) represents an agonizing problem in many countries, especially in rural areas. This clinical and neurophysiological study aimed to determine the relative frequency of scorpion envenomation in the Assiut area, in Upper Egypt. Full clinical evaluation was carried out for all children ≤18 y of age included in the study. Electroencephalography (EEG), electromyography (EMG) and motor conduction velocity measurements were carried out for a variable number of children. SE was recorded in 302 cases per year in this area. Of these, 78.5% were ≤18 y of age. SE occurred most commonly during the summer months. Clinical evaluation revealed that SE results in marked autonomic manifestations, principally sinus tachycardia (78.1%), vomiting (70.5%) and hyperthermia (53.2%). It also results in many neuropsychiatric manifestations, such as agitation and restlessness (17.7%) and disturbance of consciousness (8.0%). Electroencephalographic study of 184 cases of SE in paediatric patients aged ≤18 y revealed abnormalities in 77.7%. Study of mean distal latency and motor conduction velocity revealed that patients had a significantly shorter distal latency and a more rapid motor conduction velocity compared with the control group. This was true for both the inflicted limb and the contralateral limb. Most of the complications of SE are due to irritability of the central and peripheral nervous systems.     

东亚钳蝎中新分离的毒素BmTx3B抑制大鼠海马神经元延迟整流性钾电流

目的：研究从东亚钳蝎毒素中新分离的短肽BmTx3B对电压门控性钾通道的作用．方法：在酶解打散的新生大鼠海马细胞,采用全细胞电压箝位方式记录,并根据动力学特性分离二种电压依赖性钾电流．结果：BraTx3B(10-100μmol／L)选择地抑制延迟整流性钾电流(IK),不影响瞬时性快钾电流(IA)．此抑制作用是可逆的,呈现浓度依赖性,但无电压依赖性．BmTx3B对延迟整流性钾电流的稳态激活和稳态失活的动力学特性无影响．结论：蝎毒短肽BmTx3B选择地抑制海马神经元延迟整流性钾通道。     

Inhibitory effects of recombinant neurotoxin BmK IM on seizures induced by pentylenetetrazol in Rats

Askeyelementsofsignaltransmission ,voltage gatedsodiumchannelsplayacriticalrolebothinactionpotentialpropagationinexcitabletissuesandinneurotransmitterreleasefromnerveterminals Atthesametime ,thesechannelsarealsothetargetsofneurotoxinsfromvariousscorpionspecies Theeffectsofthesetoxinsonsodiumchannelsinvolvemodificationstochannelgatingandmembranepermeability 1,2Ithasbeendemonstratedthatmostscorpionneurotoxinsarelong chainproteinswith 60 -80aminoacids,cross linkedbyfourdisulfidebridges Generally …     

Evidence for a function-specific mutation in the neurotoxin,parabutoxin 3

Parabutoxin 3 (PBTx3), a short-chain alpha-K+ neurotoxin from the scorpion, Parabuthus transvaalicus, is a 37-residue polypeptide cross-linked by three disulphide bridges. The affinity towards Kv1 channels is very weak (Kd approximately 79 micro m for Kv1.1 channels), or moderate (Kd approximately 500 nm for Kv1.2 and Kv1.3 channels). In an effort to generate a more potent K+ channel blocker, we recombinantly produced a mutant PBTx3 by the introduction of an aromatic amino acid, fenylalanine in close proximity of the crucial lysine 26 residue, to create a functional diad similar to subfamily three alpha-K+ toxins. The mutant was tested for his ability to block Kv1.1, Kv1.2 and Kv1.3 channels in Xenopus laevis oocytes: a hundred-fold higher affinity towards Kv1.1 channels and a fivefold increase in affinity towards Kv1.3 channels was observed, when compared to the wild-type toxin. The effect on Kv1.2 channels was similar to the wild-type toxin, indicating a specific interaction site for the mutated residue onto the different Kv-type channels.     

蝎素组分Ⅲ对Jurkat E6-1细胞中LAT和SLP-76表达的影响

目的研究蝎素组分Ⅲ(SVC-Ⅲ)对Jurkat E6-1细胞LAT和SLP-76表达的影响,并探讨SVC-Ⅲ参与细胞免疫调控的可能机制。方法不同浓度SVC-Ⅲ(100 ng.mL-1、10 ng.mL-1、1 ng.mL-1、0.1 ng.mL-1)与植物凝集素(PHA)共同刺激培养Jurkat E6-1细胞。72 h后收获细胞,利用逆转录聚合酶链反应(RT-PCR)技术检测细胞内信号分子LAT和SLP-76 mRNA表达变化情况。结果高浓度SVC-Ⅲ(100 ng.mL-1)明显抑制Jurkat E6-1细胞LAT和SLP-76的mRNA的表达(P<0.05),低浓度SVC-Ⅲ(0.1 ng.mL-1、1 ng.mL-1、10 ng.mL-1)对Jurkat E6-1细胞LAT和SLP-76的mRNA的表达没有明显作用(P>0.05)。结论SVC-Ⅲ能够抑制Jurkat E6-1细胞LAT和SLP-76的表达,在一定程度上阻止T细胞信号进一步的传递,从而抑制Jurkat E6-1细胞的活化能力。并且SVC-Ⅲ可抑制PHA诱导的Jurkat E6-1细胞的活化,其作用机制可能与早期活化相关的LAT和SLP-76等的表达相关。