44 resultados para Bungarus candidus
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CCBE S. XVI, F, 995
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The wild mushroom Leucopaxillus candidus (Bres.) Singer was studied for the first time to obtain information about its chemical composition, nutritional value and bioactivity. Free sugars, fatty acids, tocopherols, organic and phenolic acids were analysed by chromatographic techniques coupled to different detectors. L. candidus methanolic extract was tested regarding antioxidant potential (reducing power, radical scavenging activity and lipid peroxidation inhibition). L. candidus was shown to be an interesting species in terms of nutritional value, with high content in proteins and carbohydrates, but low fat levels, with the prevalence of polyunsaturated fatty acids. Mannitol was the most abundant free sugar and β-tocopherol was the main tocopherol isoform. Other compounds detected were oxalic and fumaric acids, p-hydroxybenzoic and cinnamic acids. The methanolic extract revealed antioxidant activity and did not show hepatoxicity in porcine liver primary cells. The present study provides new information about L. candidus.
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A double antibody sandwich enzyme linked immunosorbent assay (ELISA) was developed to detect Echis carinatus venom in various organs (brain, heart, lungs, liver, spleen and kidneys) as well as tissue at the site of injection of mice, at various time intervals (1, 6, 12, 18, 24 h and 12 h intervals up to 72 h) after death. The assay could detect E. carinatus venom levels up to 2.5 ng/ml of tissue homogenate and the venom was detected up to 72 h after death. A highly sensitive and species-specific avidin-biotin microtitre ELISA was also developed to detect venoms of four medically important Indian snakes (Bungarus caeruleus, Naja naja, E. carinatus and Daboia russelli russelli) in autopsy specimens of human victims of snake bite. The assay could detect venom levels as low as 100 pg/ml of tissue homogenate. Venoms were detected in brain, heart, lungs, liver, spleen, kidneys, tissue at the bite area and postmortem blood. In all 12 human victim cadavers tested the culprit species were identified. As observed in mice, tissue at the site of bite area showed the highest concentration of venom and the brain showed the least. Moderate amounts of venoms were found in liver, spleen, kidneys, heart and lungs. Development of a simple, rapid and species-specific diagnostic kit based on this ELISA technique useful to clinicians is discussed.
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The nicotinic Acetylcholine Receptor (nAChR) is the major class of neurotransmitter receptors that is involved in many neurodegenerative conditions such as schizophrenia, Alzheimer's and Parkinson's diseases. The N-terminal region or Ligand Binding Domain (LBD) of nAChR is located at pre- and post-synaptic nervous system, which mediates synaptic transmission. nAChR acts as the drug target for agonist and competitive antagonist molecules that modulate signal transmission at the nerve terminals. Based on Acetylcholine Binding Protein (AChBP) from Lymnea stagnalis as the structural template, the homology modeling approach was carried out to build three dimensional model of the N-terminal region of human alpha(7)nAChR. This theoretical model is an assembly of five alpha(7) subunits with 5 fold axis symmetry, constituting a channel, with the binding picket present at the interface region of the subunits. alpha-netlrotoxin is a potent nAChR competitive antagonist that readily blocks the channel resulting in paralysis. The molecular interaction of alpha-Bungarotoxin, a long chain alpha-neurotoxin from (Bungarus multicinctus) and human alpha(7)nAChR seas studied. Agonists such as acetylcholine, nicotine, which are used in it diverse array of biological activities, such as enhancements of cognitive performances, were also docked with the theoretical model of human alpha(7)nAChR. These docked complexes were analyzed further for identifying the crucial residues involved i interaction. These results provide the details of interaction of agonists and competitive antagonists with three dimensional model of the N-terminal region of human alpha(7)nAChR and thereby point to the design of novel lead compounds.
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En Nicaragua el género Phaseolus, representa una fuente importante de nutrientes que la población incluye en su dieta diaria, además provee ingresos a los productores con los que subsanan una parte de sus necesidades, El 95% de la producción de frijol en el país descansa en pequeños y medianos productores que enfrentan problemas como: Falta de asistencia técnica, poca o ninguna disponibilidad de créditos, poseen terrenos no adecuados para este cultivo y el uso constante de semillas remanentes de un ciclo a otro; Esto ha incidido de forma directa en la disminución de los rendimientos y en el aumento de los niveles de inoculo en la semilla. Son muchas las enfermedades que atacan a esta leguminosa y algunas de estas llegan a infestar y/o infectar la semilla logrando así un eficiente mecanismo de dispersión. Con el objetivo de conocer sobre la calidad fitosanitaria de la semilla utilizada por los productores, evaluar algunas técnicas para la preservación de la misma, determinar el nivel de conocimiento de los productores con respecto a las enfermedades y discernir sobre la efectividad de las técnicas de almacenamiento de la semilla utilizadas por los productores, se realizó este trabajo involucrando 75 productores del país, logrando recolectar de sus manos un total de 15 variedades las que corresponden a los nombres de: DOR-364, RAB-310, Honduras-46, Estelí-150, Estelí-90A, Estelí-B, Negro, Blanco, Chiricano, Rojo criollo, DICTA-114, Balin tíco, Revolución-84 y dos variedades del Centro Nacional de Investigación Agropecuaria (CNIA), DOR-805 y DOR-576. El trabajo se dividió en dos fases: una de campo que consistió en la colecta de datos y muestras de semillas en las zonas de estudio en el mes de Marzo y una de laboratorio en la que se determinaron los diferentes tipos de microorganismos presente en las semillas a través de Observación de síntomas, pruebas de laboratorio y identificación de los microorganismos. Se hizo una prueba de almacenaje mediante el uso de botes plásticos con tapadera, los tratamientos utilizados para la preservación fueron• Cal, Ceniza y Ceniza+Cal en dosis de 80gr de producto por libra de semilla, más o menos 25 libras por quintal de grano y un testigo. Los resultados de las encuestas demuestran que los productores reconocen las enfem1edades como tales, pero no pueden diferenciarlas en su totalidad como causadas por hongos, bacterias o virus. Se identificaron los siguientes patógenos: Rhizoctonia sotaní, Thanatephoms cucumeris, Collectotrichum lindemuthianum, Fusarium solani, Fusarium poae, Fusarium tricinctum, l-i1sarium oxyspomm, Penicillium .;pp, Aspergillus ochraceus, Aspergillus ustus, Aspergillus glaucus (Emericella nidulans)(Eim>tium link), Aspergiilus niger, Aspergillus parasitim Aspergillus candidus, Aspergillus terreus, Rhizopus oryzae, Rhizopus stolonifer, Xanthomona;• campestris pv phaseoli, Pseudomonas spp, el virus del mosaico común no se detectó en este trabajo. Los mejores resultados se observaron en los tratamientos de cal y cal+ceniza, siendo cal+ceniza quién presentó alta significancia en la disminución de la infección por hongos, gorgojos (Bruchidae) y bacterias, pudiendo disminuir hasta un 57% las infecciones de hongos, un 68% de las infecciones por bacterias a nivel superficial y un l 00% la población de gorgojos, con respecto a las presentadas por el testigo de laboratorio. El tratamiento de cal+ceniza es más barato, eficaz y menos peligroso que el uso de cualquier químico.
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The present communication is a survey report carried out to assess the incidence of toxic mycoflora on seven types of agriculture products/by products incorporated during fish culture as supplementary dietary items. Samples were obtained from various sources at Darbhanga, Madhubani and Samashtipur districts during summer, winter and monsoon months. Out of the total 1774 samples, only 894 appeared to be fresh visually reflecting average incidence of contamination around 46.6%. However, the apparently fresh samples, when subjected to culture, 26.9% of them were found to be contaminated. Thus, degree of fungal spoilage in feed ingredients in parts of north Bihar appears to be significantly high (73.5%). The present study illustrates the facts with special reference to Aspergillus flavus, A. parasiticus (elaborating aflatoxins) A. ochraceous, Penicilium viradicatuin (elaborating ochratoxins) and A. versicolor (elaborating sterigmatocystin). The other strains already known for their toxigenic potentials that appeared on the present substrates included A. niger, A. fumigatus, A. candidus, P. islandicum, Rhizopus spp. and Mucur spp. Studies indicate that the prevalent climatic factors like temperature and relative humidity facilitate a congenial condition almost all through the year and in particular during summer and monsoon months. But water content of the substrates is a vital factor that further accelerates the pace of mycobial spoilage. A thorough sun-drying of the agricultural commodities before prolonged storage to bring water content below the "low risk limit" may significantly reduce the incidence of molds.
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目的:从金环蛇蛇毒中分离纯化名为bungaruskunin 1的一种新型胰蛋白酶抑制剂,并从其毒腺的cDNA文库中克隆出该胰蛋白酶抑制剂的cDNA全序列.方法:通过Sephadex G-50, CM-Sephadex C-25, HPLC, RP-HPLC (C4 column)方法分离纯化bungaruskunin 1.样品的丝氨酸蛋白酶抑制剂活性则是在室温条件下50mmol·L-1 Tris-HCl, pH 7.8的缓冲液中通过对显色底物的水解抑制作用来检测的.金环蛇毒腺RNA用TRIZOL提取,并用SMARTM PCR cDNA synthesis kit (Clontech)建成cDNA文库.根据其信号肽的保守区域合成引物从该文库中扩增出bungaruskunin 1的cDNA全序列,进行胶回收,酶连到pMDl8-T载体中转化测序.结果:bungaruskunin 1的前体由83个氨基酸组成,其中信号肽含有24个氨基酸,成熟肽即:bungaruskunin 1合有59个氨基酸.bungaruskunin 1的cDNA序列与从红腹伊澳蛇Pseudechis porphyriacus中分离纯化得到的丝氨酸蛋白酶抑制剂blackelin的cDNA序列的相似性高达64%.bungaruskunin 1是一种含有保守Kunitz端的Kuntiz蛋白酶抑制剂家族的一员,从而能够抑制蛋白酶和弹性酶的活性.在cDNA文库中,我们同时还筛选到了2种新的β-bungarotoxin B链的序列.结论:这些发现很好地证明了蛇中Kunitz/BPTI胰蛋白酶抑制剂和毒性神经的家族可能起源于共同的祖先.
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利用经酸处理的Sepharose 4B为层析介质,以含0.2mol/L半乳糖,pH7.4台氏液作为洗脱液,从广西产金环蛇(Bungarus fasciatus)蛇毒中一步分离得到一种磷脂酶A_(2)。用SDS-聚丙烯酰胺凝胶电泳测定其分子量为14kDa。N端部分序列测定表明,所分离得到的磷脂酶A_(2)其N端16个氨基酸残基序列与已报道的金环蛇蛇毒磷脂酶A_(2)同功酶Ⅵ(Lu&Lo,1978)一致。该酶糖含量较高,为13.4%;具有弱的磷脂酶A_(2)活性,无毒,也无溶血和出血毒活性。
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Three cDNA sequences coding for elapid cathelicidins were cloned from constructed venom gland cDNA libraries of Naja atra, Bungarus fasciatus and Ophiophagus hannah. The open reading frames of the cloned elapid cathelicidins were all composed of 576 bp an
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目的: 探讨金环蛇毒心脏毒对S180, EAC 腹水癌细胞的细胞毒作用。方法: 采用小白鼠腹腔和皮下接种S180, EAC 腹 水癌细胞造成小白鼠腹水模型后腹腔注射金环蛇毒心脏毒。结果: 腹腔注射金环蛇毒心脏毒, 能抑制肿瘤细胞的生长, 降低接 种率。但不能完全控制腹水和癌细胞的生长。体外试验表明有明显的细胞毒作用。台酚蓝染色镜检可见死细胞显著增加, 腹 水图片检查, 给药后细胞膜破裂, 纤维化坏死明显。结论: 能延长小白鼠存活时间。
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蛇毒和蜂毒是提供药理学活性分子的丰富来源,它们富含肽和蛋白,包括一 些酶类和毒素。 丝氨酸蛋白酶抑制剂广泛存在于动物、植物和微生物体内,参与许多重要的 生理过程,如血液凝集、纤维蛋白溶解、细胞凋亡、发育以及炎症反应和补体活 化等(van Gent D. et al., 2003)。通过凝胶过滤、离子交换和反向高压液相色谱, 我们从金环蛇毒液中纯化得到一种天然的丝氨酸蛋白酶抑制剂,命名为 bungaruskunin。并且从该蛇的毒腺cDNA 文库中克隆到了它的核苷酸序列。 bungaruskunin 预测的前体由83 个氨基酸组成,包括含有24 个氨基酸的信号肽 和含有59 个氨基酸的成熟肽。它与一种由红腹伊澳蛇(Pseudechis porphyriacus) 的cDNA 预测到的丝氨酸蛋白酶抑制剂blackelin 具有最大相似性,达64%。 Bungaruskunin 是一种Kunitz 型的蛋白酶抑制剂,具有一个保守的Kunitz 结构域, 能够抑制胰蛋白酶、胰凝乳蛋白酶和弹性蛋白酶。通过对金环蛇毒腺cDNA 文库 的筛选,我们还得到了另外两条β-bungarotoxin B 链,Bungaruskunin 的整体结 构与β-bungarotoxin B 链相似,特别是它们都具有高度保守的信号肽序列。这些 发现强烈地表明蛇毒Kunitz/BPTI 蛋白酶抑制剂与神经毒性的类似物可能起源于 共同的祖先。 肥大细胞脱粒肽是从膜翅目昆虫的毒液中鉴别出的一个小肽家族,是一种具 有潜在的药物治疗作用的诱导活性分子(Xueqing Xu et al., 2006)。来源于蜂类的 缓激肽样的类似物vespakinin 家族是一种具有调节和激素功能的活性成分,与哺 乳动物和两栖动物的缓激肽类似(Nakajima T., 1984)。本研究对三种胡蜂的 毒液进行了一系列的活性检测,发现黑尾胡蜂的蜂毒对白色念珠菌Candida albicans 和金黄色葡萄球菌 Staphylococcus aureus 有抑制作用。凹纹胡蜂和黑尾 胡蜂的蜂毒具有微弱的磷酯酶A2 活性。通过凝胶过滤和反向高压液相色谱,没 有得到相关的活性组分。通过对三种胡蜂毒腺cDNA 文库的筛选,我们得到了2 条来源于黑尾胡蜂的核苷酸序列,Blast 分析表明,其中一条编码类似肥大细胞 脱粒肽,但未克隆到全长,序列比对结果显示其与来源于大胡蜂(Vespa magnifica) 的Mastoparan-like peptide 12c precursor(GenBank accession A0SPI0)的核苷酸序 列相似性达98%(Xueqing Xu et al., 2006);另一条编码缓激肽类似物,命名为 Hw-bradykinin,序列比对结果显示其与来源于大胡蜂(Vespa magnifica)的 vespakinin-M precursor(GenBank accessionABG75944)的核苷酸相似率达96% (Zouhong Zhou et al., 2006)。
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Cathelicidins是动物体内一个具有多功能的抗菌肽家族,目前仅在哺乳类、鸟类、爬行类和鱼类中有发现。Cathelicidins具有广谱的抗微生物活性,不但对普通革兰氏阳性细菌、革兰氏阴性细菌、真菌以及病毒具有非常强的活性,而且对许多临床耐药微生物同样具有作用。除此之外,cathelicidins具有许多其他生物学活性,如对多种免疫细胞具有趋化作用、诱导肥大细胞脱粒和组织胺释放、调节巨噬细胞转录、促进伤口愈合、诱导血管发生、诱导变异细胞系细胞凋亡和淋巴细胞活化等。 金环蛇(Bungarus fasciatus)属于眼镜蛇科(Elapinae)环蛇属(Bungarus),是一种具有前沟牙的毒蛇,广泛分布于我国广东、广西、福建、江西、海南及云南南部。 在本论文中,我们对金环蛇体内cathelicidins家族抗菌肽cathelicidin-BF进行了一系列研究。 通过凝胶过滤、阳离子交换和反相高压液相三步从金环蛇蛇毒冻干粉中分离纯化得到金环蛇cathelicidins家族抗菌肽,命名为cathelicidin-BF。Edman降解法测定其氨基酸序列为KFFRKLKKSVKKRAKEFFKKPRVIGVSIPF,由30个氨基酸残基组成,ESI-MS测得其分子量为3637.5 Da。 构建了金环蛇毒腺cDNA文库,从中克隆得到了编码cathelicidin-BF前体的cDNA序列。该cDNA序列长度为750 bp,由此推断出的cathelicidin-BF前体由191个氨基酸残基组成,包括信号肽区、保守的cathelin区和成熟肽区三部分。用RT-PCR的方法对cathelicidin-BF的组织表达情况进行了研究,结果表明cathelicidin-BF在金环蛇胃、气管、皮肤、肌肉、心脏、肾脏、肺、脑、小肠、脾脏、肝脏、卵巢、毒腺中均有表达,但各组织表达量存在差异。进化分析表明,金环蛇cathelicidin-BF与鸭嘴兽CATH-3在系统进化树中独立成簇,表明金环蛇与鸭嘴兽有着一定的亲缘关系,这为鸭嘴兽在动物进化中分类地位的确定提供了参考资料。 对cathelicidin-BF可能具有的各种生物学活性进行了研究。Cathelicidin-BF具有广谱的抗微生物活性,对革兰氏阳性细菌、革兰氏阴性细菌和真菌均有活性,Cathelicidins是动物体内一个具有多功能的抗菌肽家族,目前仅在哺乳类、鸟类、爬行类和鱼类中有发现。Cathelicidins具有广谱的抗微生物活性,不但对普通革兰氏阳性细菌、革兰氏阴性细菌、真菌以及病毒具有非常强的活性,而且对许多临床耐药微生物同样具有作用。除此之外,cathelicidins具有许多其他生物学活性,如对多种免疫细胞具有趋化作用、诱导肥大细胞脱粒和组织胺释放、调节巨噬细胞转录、促进伤口愈合、诱导血管发生、诱导变异细胞系细胞凋亡和淋巴细胞活化等。 金环蛇(Bungarus fasciatus)属于眼镜蛇科(Elapinae)环蛇属(Bungarus),是一种具有前沟牙的毒蛇,广泛分布于我国广东、广西、福建、江西、海南及云南南部。 在本论文中,我们对金环蛇体内cathelicidins家族抗菌肽cathelicidin-BF进行了一系列研究。 通过凝胶过滤、阳离子交换和反相高压液相三步从金环蛇蛇毒冻干粉中分离纯化得到金环蛇cathelicidins家族抗菌肽,命名为cathelicidin-BF。Edman降解法测定其氨基酸序列为KFFRKLKKSVKKRAKEFFKKPRVIGVSIPF,由30个氨基酸残基组成,ESI-MS测得其分子量为3637.5 Da。 构建了金环蛇毒腺cDNA文库,从中克隆得到了编码cathelicidin-BF前体的cDNA序列。该cDNA序列长度为750 bp,由此推断出的cathelicidin-BF前体由191个氨基酸残基组成,包括信号肽区、保守的cathelin区和成熟肽区三部分。用RT-PCR的方法对cathelicidin-BF的组织表达情况进行了研究,结果表明cathelicidin-BF在金环蛇胃、气管、皮肤、肌肉、心脏、肾脏、肺、脑、小肠、脾脏、肝脏、卵巢、毒腺中均有表达,但各组织表达量存在差异。进化分析表明,金环蛇cathelicidin-BF与鸭嘴兽CATH-3在系统进化树中独立成簇,表明金环蛇与鸭嘴兽有着一定的亲缘关系,这为鸭嘴兽在动物进化中分类地位的确定提供了参考资料。 对cathelicidin-BF可能具有的各种生物学活性进行了研究。Cathelicidin-BF具有广谱的抗微生物活性,对革兰氏阳性细菌、革兰氏阴性细菌和真菌均有活性,Cathelicidins是动物体内一个具有多功能的抗菌肽家族,目前仅在哺乳类、鸟类、爬行类和鱼类中有发现。Cathelicidins具有广谱的抗微生物活性,不但对普通革兰氏阳性细菌、革兰氏阴性细菌、真菌以及病毒具有非常强的活性,而且对许多临床耐药微生物同样具有作用。除此之外,cathelicidins具有许多其他生物学活性,如对多种免疫细胞具有趋化作用、诱导肥大细胞脱粒和组织胺释放、调节巨噬细胞转录、促进伤口愈合、诱导血管发生、诱导变异细胞系细胞凋亡和淋巴细胞活化等。 金环蛇(Bungarus fasciatus)属于眼镜蛇科(Elapinae)环蛇属(Bungarus),是一种具有前沟牙的毒蛇,广泛分布于我国广东、广西、福建、江西、海南及云南南部。 在本论文中,我们对金环蛇体内cathelicidins家族抗菌肽cathelicidin-BF进行了一系列研究。 通过凝胶过滤、阳离子交换和反相高压液相三步从金环蛇蛇毒冻干粉中分离纯化得到金环蛇cathelicidins家族抗菌肽,命名为cathelicidin-BF。Edman降解法测定其氨基酸序列为KFFRKLKKSVKKRAKEFFKKPRVIGVSIPF,由30个氨基酸残基组成,ESI-MS测得其分子量为3637.5 Da。 构建了金环蛇毒腺cDNA文库,从中克隆得到了编码cathelicidin-BF前体的cDNA序列。该cDNA序列长度为750 bp,由此推断出的cathelicidin-BF前体由191个氨基酸残基组成,包括信号肽区、保守的cathelin区和成熟肽区三部分。用RT-PCR的方法对cathelicidin-BF的组织表达情况进行了研究,结果表明cathelicidin-BF在金环蛇胃、气管、皮肤、肌肉、心脏、肾脏、肺、脑、小肠、脾脏、肝脏、卵巢、毒腺中均有表达,但各组织表达量存在差异。进化分析表明,金环蛇cathelicidin-BF与鸭嘴兽CATH-3在系统进化树中独立成簇,表明金环蛇与鸭嘴兽有着一定的亲缘关系,这为鸭嘴兽在动物进化中分类地位的确定提供了参考资料。 对cathelicidin-BF可能具有的各种生物学活性进行了研究。Cathelicidin-BF具有广谱的抗微生物活性,对革兰氏阳性细菌、革兰氏阴性细菌和真菌均有活性,Cathelicidins是动物体内一个具有多功能的抗菌肽家族,目前仅在哺乳类、鸟类、爬行类和鱼类中有发现。Cathelicidins具有广谱的抗微生物活性,不但对普通革兰氏阳性细菌、革兰氏阴性细菌、真菌以及病毒具有非常强的活性,而且对许多临床耐药微生物同样具有作用。除此之外,cathelicidins具有许多其他生物学活性,如对多种免疫细胞具有趋化作用、诱导肥大细胞脱粒和组织胺释放、调节巨噬细胞转录、促进伤口愈合、诱导血管发生、诱导变异细胞系细胞凋亡和淋巴细胞活化等。 金环蛇(Bungarus fasciatus)属于眼镜蛇科(Elapinae)环蛇属(Bungarus),是一种具有前沟牙的毒蛇,广泛分布于我国广东、广西、福建、江西、海南及云南南部。 在本论文中,我们对金环蛇体内cathelicidins家族抗菌肽cathelicidin-BF进行了一系列研究。 通过凝胶过滤、阳离子交换和反相高压液相三步从金环蛇蛇毒冻干粉中分离纯化得到金环蛇cathelicidins家族抗菌肽,命名为cathelicidin-BF。Edman降解法测定其氨基酸序列为KFFRKLKKSVKKRAKEFFKKPRVIGVSIPF,由30个氨基酸残基组成,ESI-MS测得其分子量为3637.5 Da。 构建了金环蛇毒腺cDNA文库,从中克隆得到了编码cathelicidin-BF前体的cDNA序列。该cDNA序列长度为750 bp,由此推断出的cathelicidin-BF前体由191个氨基酸残基组成,包括信号肽区、保守的cathelin区和成熟肽区三部分。用RT-PCR的方法对cathelicidin-BF的组织表达情况进行了研究,结果表明cathelicidin-BF在金环蛇胃、气管、皮肤、肌肉、心脏、肾脏、肺、脑、小肠、脾脏、肝脏、卵巢、毒腺中均有表达,但各组织表达量存在差异。进化分析表明,金环蛇cathelicidin-BF与鸭嘴兽CATH-3在系统进化树中独立成簇,表明金环蛇与鸭嘴兽有着一定的亲缘关系,这为鸭嘴兽在动物进化中分类地位的确定提供了参考资料。 对cathelicidin-BF可能具有的各种生物学活性进行了研究。Cathelicidin-BF具有广谱的抗微生物活性,对革兰氏阳性细菌、革兰氏阴性细菌和真菌均有活性,Cathelicidins是动物体内一个具有多功能的抗菌肽家族,目前仅在哺乳类、鸟类、爬行类和鱼类中有发现。Cathelicidins具有广谱的抗微生物活性,不但对普通革兰氏阳性细菌、革兰氏阴性细菌、真菌以及病毒具有非常强的活性,而且对许多临床耐药微生物同样具有作用。除此之外,cathelicidins具有许多其他生物学活性,如对多种免疫细胞具有趋化作用、诱导肥大细胞脱粒和组织胺释放、调节巨噬细胞转录、促进伤口愈合、诱导血管发生、诱导变异细胞系细胞凋亡和淋巴细胞活化等。 金环蛇(Bungarus fasciatus)属于眼镜蛇科(Elapinae)环蛇属(Bungarus),是一种具有前沟牙的毒蛇,广泛分布于我国广东、广西、福建、江西、海南及云南南部。 在本论文中,我们对金环蛇体内cathelicidins家族抗菌肽cathelicidin-BF进行了一系列研究。 通过凝胶过滤、阳离子交换和反相高压液相三步从金环蛇蛇毒冻干粉中分离纯化得到金环蛇cathelicidins家族抗菌肽,命名为cathelicidin-BF。Edman降解法测定其氨基酸序列为KFFRKLKKSVKKRAKEFFKKPRVIGVSIPF,由30个氨基酸残基组成,ESI-MS测得其分子量为3637.5 Da。 构建了金环蛇毒腺cDNA文库,从中克隆得到了编码cathelicidin-BF前体的cDNA序列。该cDNA序列长度为750 bp,由此推断出的cathelicidin-BF前体由191个氨基酸残基组成,包括信号肽区、保守的cathelin区和成熟肽区三部分。用RT-PCR的方法对cathelicidin-BF的组织表达情况进行了研究,结果表明cathelicidin-BF在金环蛇胃、气管、皮肤、肌肉、心脏、肾脏、肺、脑、小肠、脾脏、肝脏、卵巢、毒腺中均有表达,但各组织表达量存在差异。进化分析表明,金环蛇cathelicidin-BF与鸭嘴兽CATH-3在系统进化树中独立成簇,表明金环蛇与鸭嘴兽有着一定的亲缘关系,这为鸭嘴兽在动物进化中分类地位的确定提供了参考资料。 对cathelicidin-BF可能具有的各种生物学活性进行了研究。Cathelicidin-BF具有广谱的抗微生物活性,对革兰氏阳性细菌、革兰氏阴性细菌和真菌均有活性,Cathelicidins是动物体内一个具有多功能的抗菌肽家族,目前仅在哺乳类、鸟类、爬行类和鱼类中有发现。Cathelicidins具有广谱的抗微生物活性,不但对普通革兰氏阳性细菌、革兰氏阴性细菌、真菌以及病毒具有非常强的活性,而且对许多临床耐药微生物同样具有作用。除此之外,cathelicidins具有许多其他生物学活性,如对多种免疫细胞具有趋化作用、诱导肥大细胞脱粒和组织胺释放、调节巨噬细胞转录、促进伤口愈合、诱导血管发生、诱导变异细胞系细胞凋亡和淋巴细胞活化等。 金环蛇(Bungarus fasciatus)属于眼镜蛇科(Elapinae)环蛇属(Bungarus),是一种具有前沟牙的毒蛇,广泛分布于我国广东、广西、福建、江西、海南及云南南部。 在本论文中,我们对金环蛇体内cathelicidins家族抗菌肽cathelicidin-BF进行了一系列研究。 通过凝胶过滤、阳离子交换和反相高压液相三步从金环蛇蛇毒冻干粉中分离纯化得到金环蛇cathelicidins家族抗菌肽,命名为cathelicidin-BF。Edman降解法测定其氨基酸序列为KFFRKLKKSVKKRAKEFFKKPRVIGVSIPF,由30个氨基酸残基组成,ESI-MS测得其分子量为3637.5 Da。 构建了金环蛇毒腺cDNA文库,从中克隆得到了编码cathelicidin-BF前体的cDNA序列。该cDNA序列长度为750 bp,由此推断出的cathelicidin-BF前体由191个氨基酸残基组成,包括信号肽区、保守的cathelin区和成熟肽区三部分。用RT-PCR的方法对cathelicidin-BF的组织表达情况进行了研究,结果表明cathelicidin-BF在金环蛇胃、气管、皮肤、肌肉、心脏、肾脏、肺、脑、小肠、脾脏、肝脏、卵巢、毒腺中均有表达,但各组织表达量存在差异。进化分析表明,金环蛇cathelicidin-BF与鸭嘴兽CATH-3在系统进化树中独立成簇,表明金环蛇与鸭嘴兽有着一定的亲缘关系,这为鸭嘴兽在动物进化中分类地位的确定提供了参考资料。 对cathelicidin-BF可能具有的各种生物学活性进行了研究。Cathelicidin-BF具有广谱的抗微生物活性,对革兰氏阳性细菌、革兰氏阴性细菌和真菌均有活性,其中包括大量临床分离耐药菌株。Cathelicidin-BF对革兰氏阴性细菌的活性要强于革兰氏阳性细菌,此外对白色念珠菌、毕赤酵母和一些腐生性真菌也具有活性。Cathelicidin-BF的抗氧化活性、溶血活性、凝集素活性、丝氨酸蛋白酶和丝氨酸蛋白酶抑制剂活性、细胞毒性、抗肿瘤活性均不明显。Cathelicidin-BF具有很强的肥大细胞脱颗粒活性。以上结果表明cathelicidin-BF在金环蛇抵御外界病原微生物侵袭的先天免疫反应中可能发挥了重要作用。 利用多种实验方法对cathelicidin-BF的结构和抗菌机理进行了研究。CD和NMR的实验结果表明,在亲水环境中,cathelicidin-BF为无规卷曲的构象;在疏水或模拟细菌细胞质膜的环境中,cathelicidin-BF的N-末端区域具有典型的两亲性α-螺旋构象。杀菌动力学实验结果表明,cathelicidin-BF杀菌作用极其迅速,在浓度大于1×MIC时,在1 min内即可杀死所有细菌,且其杀菌作用是致死性的。扫描电镜结果表明,经过cathelicidin-BF处理的细菌细胞形状发生明显改变,细胞膨胀变形,表面出现大量囊泡状结构。大量细菌细胞破裂溶解,内容物外泄。综合以上结果我们推测:cathelicidin-BF在亲水的环境中为无规卷曲的结构,当通过静电相互作用吸附到细菌细胞质膜上后,由于环境疏水性的增加其N-端转变为两亲性的α-螺旋构象。Cathelicidin-BF的疏水侧插入到细菌细胞质膜内部,亲水侧暴露于细菌细胞质膜表面。随着结合到细菌细胞质膜上的cathelicidin-BF分子不断增加,细菌细胞质膜内陷,最终在细菌细胞质膜上形成孔洞。细菌细胞内容物大量外流,最终导致细菌细胞的死亡。 通过体外和体内多个实验对cathelicidin-BF进行了初步的药理学和药效学研究。Cathelicidin-BF在血清中稳定性较差,容易被血清中各种蛋白酶降解。一定浓度的盐离子能够增强cathelicidin-BF的抗菌活性。动物模型实验表明,cathelicidin-BF对多种细菌引起的小鼠皮肤感染具有很好的治疗效果。Cathelicidin-BF本身所具有的特点及动物模型实验中表现出的极佳的治疗效果使其成为外用抗菌药物开发的优良模板。
Resumo:
报道了中国担子菌纲一新记录属——哈宁管菌属Henningsomyces,并对采集于云南省迪庆州香格里拉县千湖山冷杉倒木上的一新记录种雪白哈宁管菌Henningsomyces candidus进行了详细描述。该菌最典型的形态特征是担子果由许多白色小管直立排列而成,菌丝体为一体系,同时具有简单分隔和锁状联合,担孢子薄壁、光滑、近椭圆形,菌管口的菌丝呈明显的树状分枝。
Resumo:
As análises micológica e micotoxicológica representam uma parte importante da monitorização da qualidade e segurança dos alimentos compostos para animais. O objectivo deste trabalho foi avaliar o nível de contaminação fúngica em amostras de alimentos compostos para suínos, identificar as espécies fúngicas presentes e quantificar os níveis de zearalenona (ZEA) e deoxinivalenol (DON). Para tal, foram analisadas 55 amostras, encontrando-se 52 (94.5%) contaminadas com fungos, apresentando teores médios de 1.7×104 UFC/g. Os fungos mais predominantes foram o Fusarium spp (81.8%), o Aspergillus flavus (69.0%), as leveduras (60.0%) e o Aspergillus candidus (56.3%). A análise micotoxicológica foi efectuada por Cromatografia Líquida de Alta Performance (HPLC), com purificação por colunas IAC (Colunas de imunoafinidade), e revelou 18 amostras positivas para ZEA e 13 positivas para DON, com níveis de ZEA variando entre 6.1 e 5.4×101 μg/kg, e de DON variando de 1.0×102 e 9.0×102 μg/kg. Foi observada co-ocorrência em 3 amostras (5.5%). Todos os resultados encontrados estavam abaixo dos limites máximos permitidos pela União Europeia (UE). As taxas de recuperação para amostras contaminadas com ZEA, a concentrações de 0.005; 0.010 e 0.10 μg/kg foram de 93.0; 95.0 e 95.0%, respectivamente e as de DON foram de 98.0; 85.0 e 88.0%, para soluções contaminadas com 100.0; 250.0 e 500.0 μg/kg, respectivamente.
Resumo:
The nicotinic Acetylcholine Receptor (nAChR) is the major class of neurotransmitter receptors that is involved in many neurodegenerative conditions such as schizophrenia, Alzheimer's and Parkinson's diseases. The N-terminal region or Ligand Binding Domain (LBD) of nAChR is located at pre- and post-synaptic nervous system, which mediates synaptic transmission. nAChR acts as the drug target for agonist and competitive antagonist molecules that modulate signal transmission at the nerve terminals. Based on Acetylcholine Binding Protein (AChBP) from Lymnea stagnalis as the structural template, the homology modeling approach was carried out to build three dimensional model of the N-terminal region of human alpha(7)nAChR. This theoretical model is an assembly of five alpha(7) subunits with 5 fold axis symmetry, constituting a channel, with the binding picket present at the interface region of the subunits. alpha-netlrotoxin is a potent nAChR competitive antagonist that readily blocks the channel resulting in paralysis. The molecular interaction of alpha-Bungarotoxin, a long chain alpha-neurotoxin from (Bungarus multicinctus) and human alpha(7)nAChR seas studied. Agonists such as acetylcholine, nicotine, which are used in it diverse array of biological activities, such as enhancements of cognitive performances, were also docked with the theoretical model of human alpha(7)nAChR. These docked complexes were analyzed further for identifying the crucial residues involved in interaction. These results provide the details of interaction of agonists and competitive antagonists with three dimensional model of the N-terminal region of human alpha(7)nAChR and thereby point to the design of novel lead compounds.