蛇毒凝血酶原激活组分的研究概况

<正>蛇毒是一类复杂的具有多种生物学活性的蛋白质和蛋白多肽。目前已经分离纯化出许多作用于血液凝固酶促级联反应过程中的一个或多个环节的蛇毒组分,包括FⅡ、FⅤ、FⅦ、FⅩ等激活剂以及直接使纤维蛋白原凝聚的蛇毒凝血酶样酶。蛇毒蛋白中有一类凝血毒素作用于血液凝固酶促级联反应,发挥止血作用,作用方式:(1)激活内源性和外源性凝血途径中的各种凝血因子,从而促进血液凝固。(2)激活凝血酶原,从而发挥凝血作用。(3)直接使纤维蛋白原变成纤维蛋白,即类似凝血酶样作用[1]。现已在临床上广泛     

应用蛋白组学方法筛选和鉴定乙型肝炎病毒PreS1结合蛋白

前S1蛋白（PreS1）在乙型肝炎病毒与宿主的相互作用中起至关重要的作用．为筛选乙型肝炎病毒PreS1结合蛋白,进一步探讨其在病毒感染过程中的作用,原核表达、纯化了PreS1-谷胱甘肽-S-转移酶（glutathione-S-transferase,GST）融合蛋白,利用此蛋白与HepG2细胞裂解液进行Pull-down实验,其产物进行双向凝胶电泳分离. 结果发现2个PreS1特异结合蛋白,经质谱鉴定为分子伴侣蛋白——葡萄糖调节蛋白78(GRP78)和葡萄糖调节蛋白75(GRP75)．通过免疫共沉淀和Western印迹分析证实,PreS1与GRP75之间存在相互作用．实验结果表明,GRP75为新发现乙型肝炎病毒PreS1特异结合蛋白,其与PreS1结合后的生理功能以及在HBV感染过程中的作用值得深入研究．     

江浙蝮蛇蛇毒蛋白诱导K562细胞调亡的研究

目的：研究江浙蝮蛇蛇毒蛋白诱导K562细胞调亡。方法：通过电镜观察蛇毒蛋白作用后K562细胞的形态变化;MTT检测蛇毒蛋白对细胞增值的影响,同时应用流式细胞仪检测细胞凋亡数及其对细胞周期的影响;采用琼脂糖凝胶电泳观测凋亡片断。结果：蛇毒蛋白作用K562细胞后,能显著抑制细胞增值;LC50为4．96μg／mL,电镜可观察到凋亡形态学改变;电泳呈现典型的阶梯状条带,流式细胞仪检测到凋亡峰。结论：江浙蝮蛇蛇毒蛋白可诱导K562细胞调亡。     

Ca~(2+)结合蛋白Rcn2的生理学功能

Rcn2(Reticulocalbin2)是一种普遍存在于哺乳动物细胞中的分泌蛋白,它不仅是细胞维持正常生理功能所必需的,更参与了肿瘤细胞的生长侵袭,并且与动脉粥样硬化易感基因、乳头瘤病毒结合蛋白E6、丝氨酸/苏氨酸激酶40、维生素D受体等生物分子相互作用,在动脉粥样硬化、宫颈癌、维生素D吸收异常等疾病中发挥着重要的调控作用。该文就Rcn2对人乳头瘤病毒、Taipoxin蛇毒摄入突触机制、SOC钙离子通道、EGFR-ERK信号通路、ERK-MAPK信号通路的影响及分子作用机制等方面的最新研究进行概述,总结了Rcn2及其相互作用分子的重要功能,为结直肠癌、肝癌、动脉粥样硬化等疾病的诊断和治疗提供重要的科学依据。     

胃癌相关新蛋白Raf激酶抑制蛋白相互作用蛋白质的鉴定

Raf激酶抑制蛋白(RKIP)的异常表达在胃癌的发生发展中起重要的作用,为了阐明其作用机制,应用脂质体将RKIP-3xFLAG-pcDNA3.1质粒转染至SGC7901细胞,建立RKIP-3xFLAG高表达的SGC7901细胞;并利用3xFLAG标签的亲和层析技术联合质谱分析,分离、鉴定与RKIP相互作用的蛋白质,并应用免疫共沉淀联合Western-blot进一步验证质谱结果．共鉴定出66个RKIP相互作用蛋白质,功能分类包括蛋白质代谢酶类、生物氧化相关酶类,细胞骨架蛋白、分子伴侣、信号转导相关蛋白、酶解相关蛋白等．并首次证实14-3-3蛋白与RKIP存在相互作用．为阐明RKIP在胃癌发生发展中的作用机制提供了重要的线索,为胃癌的早期诊治及预后监测提供了新的靶点．     

受体相互作用蛋白3——细胞凋亡与坏死的调节阀

综述了受体相互作用蛋白(RIPs)蛋白结构和RIP3调控细胞凋亡与坏死机制的研究进展．受体相互作用蛋白3(receptor-interacting protein 3, RIP3)是丝/苏氨酸蛋白激酶家族成员之一,该蛋白质家族包含一类高度保守的丝/苏氨酸激酶结构域．RIP家族激酶作为细胞应激传感分子,在调控细胞凋亡、细胞坏死和存活通路中发挥重要作用．近年发现,RIP3参与肿瘤坏死因子TNFα诱导的细胞程序化坏死的生物学过程．认识RIP3调控TNFα诱导的细胞凋亡与坏死不同死亡途径转换的分子机制,有助于发现肿瘤治疗的新策略．     

NLS-RARα蛋白相互作用蛋白的筛选与验证

急性早幼粒细胞白血病(APL)具有特征性染色体易位,产生的PML-RARα融合基因在其发生发展中有重要作用．PML-RARα融合蛋白在细胞内被中性粒细胞弹性蛋白酶(neutrophil elastase,NE)切割为PML突变蛋白(核定位信号NLS缺失)和RARα突变体 (NLS-RARα,包含有PML的核定位信号),这两段蛋白质在APL的发生中可能具有重要作用．为进一步研究NLS-RARα的生物学功能,运用酵母双杂交技术在白血病cDNA文库中筛选与其作用的蛋白质．首先PCR技术扩增NLS-RARα编码序列,克隆至诱饵载体pGBKT7,测序鉴定后将其转化酵母AH109．免疫印迹检测到诱饵蛋白表达后,将含有诱饵载体的AH109与含有白血病cDNA文库的酵母Y187交配,在含有X-α-gal的营养缺陷性培养基上选择和筛选二倍体酵母．经回转实验和测序分析验证得到8个与NLS-RARα相互作用的蛋白质．为进一步验证这些相互作用,克隆其中的JTV-1蛋白,利用间接免疫荧光,GST pull-down和免疫共沉淀技术成功验证了它与NLS-RARα的相互作用．为进一步探讨APL的发生机制提供了新的线索．     

乌梢蛇血清的抗出血因子:一个有前途的抗蛇毒药物原料

用柱层析和聚丙烯酰胺凝胶盘状电泳法,从乌梢蛇血清中分离纯化了一个抗出血因子。用SDS-聚丙烯酰胺凝胶电泳法测得其分子量大约为65 kD;测定了五种蝮亚科蛇毒(尖吻蝮、竹叶青蛇、原矛头蝮、哈扑和短尾蝮)的最小出血剂量和乌梢蛇血清中抗出血因子对这五种蛇毒的抗出血活性;还测定了七种蛇毒(除上述五种毒蛇外,还包括圆斑蝰和银环蛇)的半数致死量,以及抗出血因子对中毒小鼠的治疗作用。结果显示:从乌梢蛇血清中提纯的抗出血因子的抗蛇毒活性,不仅可以抵抗它的捕食者尖吻蝮的蛇毒,而且还可以抵抗具出血活性的其它蛇毒;但它对不具出血活性的银环蛇毒的致死抑制作用不明显。该抗出血因子不仅在体外实验表现出强的中和出血毒素的活性,而且在体内实验中亦表现出对中毒小鼠良好的治疗作用,因而可能成为新的抗蛇毒药物的有前途的原料。乌梢蛇血清对血循毒的中和能力的获得,可能归因于尖吻蝮与乌梢蛇之间捕食与被捕食相互作用的关系。     

α-神经毒素与烟碱型乙酰胆碱受体相互作用的研究进展

α-神经毒素(α-neurotoxin,α-NTX)是眼镜蛇科和海蛇科蛇毒的主要毒性成分之一,属一种非酶类多肽,能以特异的、几乎不可逆的状态与烟碱型乙酰胆碱受体(nicotinic acetylcholine receptor,nAChR)结合。nAChR在生物学、病理学、生理学等方面发挥着重要作用,与感觉、认知、疼痛、保护神经元和递质释放等关系密切。神经型nAChR参与多种脑功能,与多种神经退行性疾病的发生密切相关,如阿尔茨海默病(AD)、帕金森病(PD)和精神分裂症(Sz)等。因此,研究α-NTX与nAChR的相互作用关系及其作用机制,对深入研究神经活动机制及相关疾病的治疗机理和寻找新型药物等具有重要意义。对α-NTX、nAChR的结构以及它们之间相互作用的研究进展进行了归纳和评述,对其相互作用位点作了较为详细的介绍。     

蝮蛇蛇毒磷脂酶A2肌肉毒素

肌肉坏死是毒蛇咬伤引起的局部症状 ,它会引起永久性组织损伤、肢体残废甚至截肢。在过去的几年中 ,人们对蛇毒蛋白中引起肌肉坏死的成分及其作用模式进行了广泛研究。一些来源于蝮蛇的肌肉毒素被分离和定性 ,并在研究它们的作用机理和肌肉坏死的病理过程方面取得了一些进展 [1～ 3 ]。所有这些肌肉毒素都具有磷脂酶 A2 ( PL A2 )结构 ,但有的不具酶活性。本文对蝮蛇肌肉毒素作简要介绍。1　蝮蛇肌肉毒素的生化特性1 .1　肌肉毒素异构体　　通常具有肌肉损伤活性的蛇毒蛋白都是碱性蛋白。在单一种甚至单一个体的蛇毒蛋白中通常都能发现 P…     

Characterization and biochemical analyses of venom from the ectoparasitic wasp Nasonia vitripennis (Walker) (Hymenoptera: Pteromalidae)

During parasitism, the ectoparasitic wasp Nasonia vitripennis (Walker) (Hymenoptera: Pteromalidae) induces a developmental arrest in host pupae that is sustained until the fly is either consumed by developing larvae or the onset of death. Bioassays using fluids collected from the female reproductive system (calyx, alkaline gland, acid gland, and venom reservoir) indicated that the venom gland and venom reservoir are the sources of the arrestant and inducer(s) of death. Infrared spectroscopic analyses revealed that crude venom is acidic and composed of amines, peptides, and proteins, which apparently are not glycosylated. Reversed phase high performance liquid chromatography (HPLC) and sodium dodecyl polyacrylamide gel electrophoresis (SDS-PAGE) confirmed the proteinaceous nature of venom and that it is composed mostly of mid to high molecular weight proteins in the range of 13 to 200.5 kilodaltons (kDa). Ammonium sulfate precipitation and centrifugal size exclusion membranes were used to isolate venom proteins. SDS-PAGE protein profiles of the isolated venom fractions displaying biological activity suggest that multiple proteins contribute to arresting host development and eliciting death. Additionally, HPLC fractionation coupled with use of several internal standards implied that two of the low molecular weight proteins were apamin and histamine. However, in vitro assays using BTI-TN-5B1-4 cells contradict the presence of these agents.     

湖南烙铁头蛇毒蛋白组分的双向电泳分析

烙铁头蛇是世界上剧毒的蛇种之一,其所携带的毒素能够导致严重的机体损伤。应用蛋白质双向电泳技术,对湖南烙铁头蛇蛇毒蛋白的蛋白质组分进行分析。通过等电聚焦和SDS-PAGE凝胶电泳分析获得完整的烙铁头蛇毒全蛋白质的图谱,经胶体考马斯亮蓝染色后,应用PDQuest软件对蛋白表达谱进行分析。通过等电聚焦和SDS-PAGE凝胶电泳有83个蛋白质组分被检测出来。其中大约90.00%的蛋白质的相对分子质量(Mr)分布在15～45 kDa之间,大约72.29%的蛋白质等电点(pI)在4.0～7.0之间。通过对烙铁头蛇毒的蛋白组学研究,获得其蛇毒蛋白质组分的表征特点,为后续进一步研究各组分的身份和潜在功能奠定基础,既可以提出新的治疗方案又可以为新的药理应用提供宝贵资源。     

Affinity purification of serine proteinase from Deinagkistrodon acutus venom

An affinity protocol was developed for the preparation of the main serine proteinase from Deinagkistrodon acutus venom on industrial scales. As affinity ligand, l-arginine was composed to medium and its structure was confirmed by ESI-MS analysis. The purification process consisted of one major affinity chromatography step to remove more than 95% of other proteins, and a polishing step of DEAE ion-exchange chromatography for removal of minor contaminants. The serine proteinase was 100% pure analyzed on HPLC Vydac C4 column, 99.4% on TSK G3000SW column, and 97.7% with SDS-PAGE analysis. The yield of the main serine proteinase was 3.6% of crude venom protein, the recoveries of typical fibrinogen (Fg) clotting activity and arginine esterase activity of serine proteinase were 82.2% and 84%, higher than those of other reported traditional protocols, the proteinase also showed arginine amidase activity. Reducing SDS-PAGE analysis showed that the arginine esterase was a single polypeptide with the mass of approximately 40 kDa, while MALDI-TOF-TOF-MS analysis showed that the purified proteinase should be a approximately 34 kDa glycoprotein. The desorption constant Kd and the theoretical maximum absorption Qmax on the affinity medium were 9.93 x 10(-5) and 38.1mg/g medium in absorption analysis.     

Analysis of venom constituents from the parasitoid wasp Pimpla hypochondriaca and cloning of a cDNA encoding a venom protein

Venom from Pimpla hypochondriaca, an endoparasitoid of pupae, was size-fractionated using gel filtration chromatography and analysed by SDS-PAGE in the presence and absence of reducing agent. A complex mixture of more than 20 venom constituents was identified which ranged in M(r) between approximately 5 and 100 kDa. Venom from a wide range of size fractions inhibited the motility of larval haemocytes and prevented the formation of cell aggregates when analysed in vitro, indicating that anti-haemocytic activity is mediated by multiple venom components. Sephadex A25 beads injected into the haemocoel of pupae were encapsulated within 24h. This reaction was abolished when the pupae were injected with 30 microg of venom protein, equivalent to one-fifth of a venom sac, 1h prior to implantation of the beads, confirming that venom suppresses encapsulation in pupae. Using random 5' end sequencing of a P. hypochondriaca venom gland cDNA library, we have isolated a cDNA encoding a 25.3 kDa protein containing a signal peptide and having sequence similarity to serine proteases. The N-terminal sequence of six residues from two venom proteins of 28 and 30 kDa was the same and identical to amino acids encoded by the cDNA, confirming that two mass forms of the protein are secreted into the venom sac. The N-terminal sequence of both venom proteins began nine residues towards the C terminus following the predicted signal sequence cleavage site, suggesting that the proteins are proteolytically processed before or during storage in the venom sac. The general applicability of using random 5' sequencing to identify cDNAs encoding secretory products is discussed.     

Isolation and characterization of the 32.5 kDa protein from the venom of an endoparasitic wasp

The major venom proteins from the endoparasitic wasp were analyzed for distribution in the venom gland. A 32.5 kDa protein was purified from the venom gland of the Chelonus near curvimaculatus wasp. The protein accounts for about 25% of the total protein content of the venom and each gland contains 3-6 pmol of this component. The protein is acidic in nature and anion-exchange chromatography facilitated the purification of the protein to apparent homogeneity. On testing the purified protein by in vivo bioassay, it was found to elicit an effect comparable with the complete venom. The protein does not appear to have any disulfide bonds of major structural importance exposed under SDS-denaturing conditions. Products of chemical partial digest of the purified protein at the methionyl residues by cyanogen bromide were analyzed by SDS-PAGE. The 27.6 kDa fragment retained an epitope to an antibody raised against total Chelonus venom proteins, whereas no epitopes were detected for 4.9 and 0.6 kDa fragments.     

cDNAs encoding large venom proteins from the parasitoid wasp Pimpla hypochondriaca identified by random sequence analysis

Venom from the parasitoid wasp Pimpla hypochondriaca contains numerous proteins, has potent in vitro anti-haemocytic properties, and disrupts host encapsulation responses. By sequencing 500 cDNAs randomly isolated from a venom gland library, we have identified 60 clones that encode proteins containing potential secretory signal sequences. To identify cDNAs encoding particular venom proteins, N-terminal amino acid sequences were determined for large (>30 kDa) venom proteins that had been separated using a combination of gel filtration and SDS-PAGE. We describe five of these cDNAs, which encoded residues that matched with the N-terminal sequences of previously undescribed venom proteins. cDNAs vpr1 and vpr3 encoded related proteins of approximately 32 kDa that were found in widely different fractions of gel filtration-separated venom. Neither vpr1 nor vpr3 were closely related to any other protein in the GenBank database, suggesting that they are highly specialised venom components. vpr2 encoded a 57-kDa polypeptide that was similar to a Drosophila protein, of unknown function, which lacks a signal sequence. A fourth clone, tre1, encoded a 61-kDa protein with extensive sequence similarity to trehalases. The 76-kDa sequence encoded by lac1 contained three regions which were very similar to histidine-rich copper-binding motifs, and could be aligned with the laccase from the fungus Coprinus cinereus. This study represents a significant step towards a holistic view of the molecular composition of a parasitoid wasp venom.     

In vitro effects of Echis carinatus venom on the human plasma proteome

Echis carinatus venom (EV) is a complex mixture of toxins that contribute to its lethality. EV proteolytic activity was analyzed by zymography, chromogenic assays, and SDS-PAGE. To understand the molecular mechanism of the envenomation, we investigated the in vitro effect of EV on human plasma proteins. We looked for EV protein substrates and their proteolytic fragments. We analyzed EV proteolytic activity on standard proteins such as prothrombin or fibrinogen. To set up the optimal EV:plasma protein ratio conditions, plasma was incubated with EV (treated plasma), depleted of abundant proteins, and subjected to SDS-PAGE. Samples from control and treated plasma were also analyzed by 2-DE/MALDI-TOF MS, leading to the identification of four classes of plasma proteins cleaved by EV: proteases, protease inhibitors, binding proteins, and transporters. EV mainly proteolyzes entire proteins but can also act on physiological fragments. In summary, the physiological effects of EV proteases involve other important processes in addition to blood coagulation; complement activation and hemoglobin metabolism are also affected. In particular, the cleavage of protease inhibitors appears to be the mechanism through which the venom neutralizes the body's defenses.     

Neuromuscular action of venom from the South American colubrid snake Philodryas patagoniensis

Snakes of the opisthoglyphous genus Philodryas are widespread in South America and cause most bites by colubrids in this region. In this study, we examined the neurotoxic and myotoxic effects of venom from Philodryas patagoniensis in biventer cervicis and phrenic nerve-diaphragm preparations and we compared the biochemical activities of venoms from P. patagoniensis and Philodryas olfersii. Philodryas patagoniensis venom (40 microg/mL) had no effect on mouse phrenic nerve-diaphragm preparations but caused time-dependent neuromuscular blockade of chick biventer cervicis preparations. This blockade was not reversed by washing. The highest concentration of venom tested (40 microg/mL) significantly reduced (p<0.05) the contractures to exogenous acetylcholine (55 microM and 110 microM) and K(+) (13.4 mM) after 120 min; lower concentrations of venom had no consistent or significant effect on these responses. Venom caused a concentration- and time-dependent release of creatine kinase (CK) from biventer cervicis preparations. Histological analysis showed contracted muscle fibers at low venom concentrations and myonecrosis at high concentrations. Philodryas venoms had low esterase and phospholipase A(2) but high proteolytic activities compared to the pitviper Bothrops jararaca. SDS-PAGE showed that the Philodryas venoms had similar electrophoretic profiles, with most proteins having a molecular mass of 25-80 kDa. Both of the Philodryas venoms cross-reacted with bothropic antivenom in ELISA, indicating the presence of proteins immunologically related to Bothrops venoms. RP-HPLC of P. patagoniensis venom yielded four major peaks, each of which contained several proteins, as shown by SDS-PAGE. These results indicate that P. patagoniensis venom has neurotoxic and myotoxic components that may contribute to the effects of envenoming by this species.     

大胡蜂蜂毒中多肽和蛋白质结构和功能的多样性

为证明大胡蜂Vespa magnifica(Smith)蜂毒具有较大的药用开发价值,本研究采用超高效液相色谱-质谱和电泳技术对其多肽和蛋白质的分布进行分析,发现其蛋白质的相对分子质量主要分布在17~45kDa范围内。蜂毒多肽类物质的相对分子质量呈"单峰"式分布,61%在500~3000Da范围内,为大胡蜂蜂毒中多肽含量最为丰富的部分。通过牛津杯法对蜂毒的抑菌活性进行研究,且以HepG2人肝癌细胞及B16黑色素瘤细胞为研究对象,用MTT法检测蜂毒的细胞毒性活性,证明其具有良好的抑菌作用和细胞毒活性,其结果与已报道的其他蜂类既有相似性又存在具体差异,展示了大胡蜂蜂毒的分子多样性,为后续该毒素的物质基础研究及药用价值开发提供参考。     

中国南海石头鱼毒素NeoVTX的分离纯化、基因克隆及表达

目的:分离并鉴定石头鱼粗毒液毒性成分,克隆其序列并进行原核表达。方法:利用SDS-PAGE及凝胶过滤HPLC分离石头鱼粗毒液,质谱鉴定其序列;利用RACE技术钓取毒素基因;将获得的毒素cDNA连入pET-22b(+)载体,转化宿主细胞大肠杆菌,经IPTG诱导表达,用亲和层析纯化目的蛋白。结果:从石头鱼粗毒液中分离到NeoVTX等多种蛋白质,克隆了NeoVTXα和β亚基的cDNA序列,获得了纯度为95%以上的重组α亚基蛋白。结论:中国南海石头鱼粗毒液的主要成分为NeoVTX,其α、β亚基序列与日本冲绳海域石头鱼NeoVTX的α和β亚基具有很高的同源性;大肠杆菌菌株可稳定表达α亚基。该工作为NeoVTX抗体制备奠定了基础。