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从织锦芋螺中克隆α芋螺毒素序列 总被引:13,自引:0,他引:13
为了从我国南海产织锦芋螺(Conustextile)中分离新的毒素序列并研究其应用价值,进行了织锦芋螺毒素基因的分离工作.从织锦芋螺毒管中提取mRNA,以A族芋螺毒素的信号肽编码部分和3′端非翻译部分的保守序列为引物,通过RT-PCR扩增和序列分析方法获得新的芋螺毒素序列.结果得到两种不同的α芋螺毒素序列,两者都属于α4/7亚型芋螺毒素,预测其成熟肽序列分别为Pro-Glu-Cys-Cys-Ser-Asp-Pro-Arg-Cys-Asn-Ser-Ser-His-Pro-Glu-Leu-Cys-Gly(C端Gly可能被酰胺化)和Pro-Glu-Cys-Cys-Ser-His-Pro-Ala-Cys-Asn-Val-Asp-His-Pro-Glu-Ile-Cys-Arg.采用传统的生化分离手段尚未从织锦芋螺中获得过α芋螺毒素序列,这两种α芋螺毒素作用的种属特异性、受体类型特异性和在小细胞肺癌的诊断和治疗中的应用价值有待进一步研究 相似文献
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α-芋螺毒素是近年来研究较多的一种海洋生物神经毒素,它特异性竞争结合烟碱型乙酰胆碱受体,化学结构独特。本文介绍了有关α-芋螺毒素的种类、结构特征、生物学活性和制备方法等方面的研究进展,及其在生物化学、生物学以及新药开发等方面的应用前景。 相似文献
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类芋螺毒素(CTX)基因存在于多种杆状病毒,编码富含半胱氨酸的多肽。从AcMNPV中克隆了ctx基因,利用AcMNPV杆粒操作系统构建了重组病毒Ac-pFastBac1-Pie1-ctx-eGFP和Ac-pFastBac1-Pie1-ctx。绿色荧光蛋白介导的亚细胞定位显示AcMNPV CTX定位于Tn细胞的细胞膜;抑菌实验表明,重组病毒Ac-pFastBac1-Pie1-ctx感染的胞外产物对金黄色葡萄球菌、微球菌、短小芽孢杆菌等临床致病菌具有显著的抗菌活性,但其作用机制尚需进一步阐明。 相似文献
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全世界有约800种芋螺,每种芋螺产生多达2 000种的肽类毒素,这些毒素可以作用于电压门控离子通道(Na+,K+,Ca2+)、配体门控离子通道(n ACh Rs,5-HT3R,NMDAR)、G蛋白偶联受体(神经降压素和血管加压素)和神经递质转运蛋白。虽然已有大量的芋螺毒素通过毒液分离、c DNA克隆和转录组测序获得,但已发现的芋螺毒素不足其总量的0.5%。A-超家族中α-芋螺毒素基因结构包含了一个内含子和被该内含子分开的两个外显子,成熟肽具有标准的4个半胱氨酸骨架(CC-C-C)。本研究利用具有保守性的α-芋螺毒素基因内含子序列,采用多个PCR退火温度,从海南产疣缟芋螺中克隆到了1个新的具有6个半胱氨酸骨架(CC-C-C-CC)的M-超家族芋螺毒素基因和1个含有5个半胱氨酸新颖骨架(CC-C-C-C)的未知新家族芋螺毒素,并对它们的基因结构、成熟肽序列,以及与其他M-超家族芋螺毒素的遗传进化关系进行了深入分析。首次证实保守的α-芋螺毒素基因内含子序列可能存在于其他超家族中。 相似文献
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ω-芋螺毒素及其衍生物的合成 总被引:3,自引:0,他引:3
研究ω 芋螺毒素及衍生物的结构与生物活性的关系。采用固相多肽合成法合成了ω 芋螺毒素及其衍生物。结果显示 ,ω 芋螺毒素衍生物结构稳定性和生物活性均比ω 芋螺毒素差。 相似文献
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Sea anemones are a rich source of two classes of peptide toxins, sodium channel toxins and potassium channel toxins, which
have been or will be useful tools for studying the structure and function of specific ion channels. Most of the known sodium
channel toxins delay channel inactivation by binding to the receptor site 3 and most of the known potassium channel toxins
selectively inhibit Kv1 channels. The following peptide toxins are functionally unique among the known sodium or potassium
channel toxins: APETx2, which inhibits acid-sensing ion channels in sensory neurons; BDS-I and II, which show selectivity
for Kv3.4 channels and APETx1, which inhibits human ether-a-go-go-related gene potassium channels. In addition, structurally novel peptide toxins, such as an epidermal growth factor (EGF)-like
toxin (gigantoxin I), have also been isolated from some sea anemones although their functions remain to be clarified. 相似文献
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Adriano Pinna Laura Pezzolesi Rossella Pistocchi Silvana Vanucci Stefano Ciavatta Luca Polimene 《PloS one》2015,10(9)
Toxin production in marine microalgae was previously shown to be tightly coupled with cellular stoichiometry. The highest values of cellular toxin are in fact mainly associated with a high carbon to nutrient cellular ratio. In particular, the cellular accumulation of C-rich toxins (i.e., with C:N > 6.6) can be stimulated by both N and P deficiency. Dinoflagellates are the main producers of C-rich toxins and may represent a serious threat for human health and the marine ecosystem. As such, the development of a numerical model able to predict how toxin production is stimulated by nutrient supply/deficiency is of primary utility for both scientific and management purposes. In this work we have developed a mechanistic model describing the stoichiometric regulation of C-rich toxins in marine dinoflagellates. To this purpose, a new formulation describing toxin production and fate was embedded in the European Regional Seas Ecosystem Model (ERSEM), here simplified to describe a monospecific batch culture. Toxin production was assumed to be composed by two distinct additive terms; the first is a constant fraction of algal production and is assumed to take place at any physiological conditions. The second term is assumed to be dependent on algal biomass and to be stimulated by internal nutrient deficiency. By using these assumptions, the model reproduced the concentrations and temporal evolution of toxins observed in cultures of Ostreopsis cf. ovata, a benthic/epiphytic dinoflagellate producing C-rich toxins named ovatoxins. The analysis of simulations and their comparison with experimental data provided a conceptual model linking toxin production and nutritional status in this species. The model was also qualitatively validated by using independent literature data, and the results indicate that our formulation can be also used to simulate toxin dynamics in other dinoflagellates. Our model represents an important step towards the simulation and prediction of marine algal toxicity. 相似文献
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Dor Salomon John A. Klimko David C. Trudgian Lisa N. Kinch Nick V. Grishin Hamid Mirzaei Kim Orth 《PLoS pathogens》2015,11(8)
The type VI secretion system (T6SS) is a widespread protein secretion apparatus used by Gram-negative bacteria to deliver toxic effector proteins into adjacent bacterial or host cells. Here, we uncovered a role in interbacterial competition for the two T6SSs encoded by the marine pathogen Vibrio alginolyticus. Using comparative proteomics and genetics, we identified their effector repertoires. In addition to the previously described effector V12G01_02265, we identified three new effectors secreted by T6SS1, indicating that the T6SS1 secretes at least four antibacterial effectors, of which three are members of the MIX-effector class. We also showed that the T6SS2 secretes at least three antibacterial effectors. Our findings revealed that many MIX-effectors belonging to clan V are “orphan” effectors that neighbor mobile elements and are shared between marine bacteria via horizontal gene transfer. We demonstrated that a MIX V-effector from V. alginolyticus is a functional T6SS effector when ectopically expressed in another Vibrio species. We propose that mobile MIX V-effectors serve as an environmental reservoir of T6SS effectors that are shared and used to diversify antibacterial toxin repertoires in marine bacteria, resulting in enhanced competitive fitness. 相似文献
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多肽类毒素研究是目前毒素研究的一个重点,对多肽类毒素的三维结构的研究是了解其结构与功能关系的重要基础.对蜘蛛、蝎以及芋螺这3类代表性的有毒动物的多肽类毒素在结构研究方面的进展及其三维结构的特点进行了介绍.其中,蜘蛛毒素多肽分子的结构主要发现有ICK模体(Inhibitor Cystine Knot motif)和D DH模体(disulfided-irectedh-airpin)两类,蝎毒素中长链肽类毒素分子和短链肽类毒素分子的结构明显不同,前者以CSα/β结构模体(Cyss-tabilizedα/βfold m otif)为主,后者则以α/β脚手架结构模体(α/βscaffoldm otif)为主.相对于蜘蛛和蝎而言,芋螺肽类毒素分子的三维结构则表现得更为复杂多样. 相似文献
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As the prevalence of antibiotic-resistant strains of bacteria increases, novel ways of treating infections need to be developed.
This is particularly pertinent with respect to the periodontal diseases—the most common chronic bacterial infections of man.
The use of a photosensitizer in combination with red light has been demonstrated to be effective in killing several human
pathogens, including the oral bacterium, Porphyromonas gingivalis, a major pathogen in periodontitis. Killing was associated with alterations in the molecular masses of several outer membrane
and plasma membrane proteins and these may be therapeutic targets for photodynamic therapy and other antimicrobial approaches.
To identify these photolabile proteins, we have used a panel of monoclonal antibodies raised to whole P. gingivalis. A number of the antibodies recognized various photolabile proteins. Using a combination of Western blotting and protein
sequencing the predominant photolabile proteins in P. gingivalis have been identified as the major secreted/cell surface proteases—Lys and Arg gingipain.
Received: 30 August 2000 / Accepted: 1 January 2001 相似文献
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PCR技术应用的新进展 总被引:3,自引:0,他引:3
近年来,随着PCR技术方法学的逐步改进和完善,更加显示出它的实用性.这不仅扩大了其用武之地,也促进了分子生物学的快速发展.文章着重介绍PCR在基因工程和蛋白质工程应用中的某些新进展,包括不需连接的克隆技术、随机引导/定位PCR、cDNA末端随机快速扩增、重组PCR和大引物PCR. 相似文献
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Muthuirulan Pushpanathan Jeyaprakash Rajendhran Paramasamy Gunasekaran 《International journal of peptide research and therapeutics》2013,19(4):331-336
An antifungal peptide, MMGP1 with direct cell penetrating property was recently reported from marine metagenome. The peptide showed efficient in vitro proteolytic activity, which could be associated with its antifungal activity. The proteolytic activity of MMGP1 was confirmed by tricine SDS-PAGE and gel filtration chromatography. Liquid chromatography-mass spectrometry analysis of MMGP1 treated bovine serum albumin (BSA), RNaseA and casein substrates revealed that the peptide does not have common cleavage position and it cleaves the substrates non-specifically at all peptide bonds. The proteolytic activity of MMGP1 was enhanced in the presence of Mn2+. Molecular docking studies revealed that the predicted active site residues of MMGP1 could interact with BSA, RNaseA and casein. 相似文献