分泌睫状神经营养因子腺病毒载体的构建及小量复制病毒增强其分泌表达的研究

目的：探讨复制型腺病毒能否增强增殖缺陷型腺病毒Ad5-hCNTF所携带外源基因的表达分泌。方法：亚克隆获得分泌型睫状神经营养因子的基因（ciliary neurotrophic factor）,然后将此基因插入到穿梭质粒pshuttle。pshuttle-hCNTF经pme1酶切后,CIAP去磷酸化,利用Ad-EASY腺病毒制备系统,将其与腺病毒骨架质粒pAdEasy-1共同转化大肠杆菌BJ5183,通过同源重组,筛选出含目的基因的重组型腺病毒质粒的菌株,获得大量该质粒后转染病毒包装细胞AD-293,成功包装出一种血清5型增殖缺陷型腺病毒Ad5-hCNTF。结果：经PCR鉴定该病毒含有该基因片断,Western blotting证实该病毒感染细胞后能表达CNTF蛋白。采用ELISA法检测培养液证实感染细胞能高水平地分泌CNTF。结论：体外实验表明在不同滴度的复制型腺病毒Ad5-E1＋E3＋的带动下,该病毒感染细胞后分泌表达目的蛋白的水平显著提高,为今后应用Ad作为基因治疗的载体提供实验证据。     

桂西黔南国家重点保护植物的地理分布、保护现状及对策

基于实地考察、文献资料和标本数据,借助GIS技术构建桂西黔南生物多样性保护优先区的39种国家重点保护植物空间地理分布格局,结合30m空间分辨率遥感影像解译的植被与地表覆盖数据,研究该优先区内的国家重点保护物种的生境与植被类型的关系及保护现状,并就优先区国家重点保护植物的地理分布格局分析优先区以外的保护空缺。此外,对优先区近二十年来的植被与地表覆盖特征的时空变化进行分析研究,结果优先区的人居用地、湿地(包括水库)面积分别增加67.75km2和371.11km2,森林面积相对稳定,灌丛和草丛面积分别减少230.69km2和174.70km2。该地区的国家重点保护植物正面临着生境退化和丧失的威胁。在此基础上对国家重点保护植物今后的保护及监测提出了对策和建议,为生物多样性研究、保护空缺分析、植被时空变化研究以及动态监测等方面的工作提供借鉴。     

Cytotoxic quinazoline alkaloids from the seeds of Peganum harmala

Seventeen quinazoline alkaloids and derivatives, containing two pairs of new epimers, named as (S)- and (R)-1-(2-aminobenzyl)-3-hydroxypyrrolidin-2-one β-d-glucopyranosyl-(1?→?6)-β-d-glucopyranoside (1, 2), (S)- and (R)-vasicinone β-d-glucopyranosyl-(1?→?6)-β-d-glucopyranoside (3, 4), and a new enantiomer (12b), together with six known ones (5–8, 10, and 12a), and three pairs of known enantiomers (9, 11, and 13), were isolated from the ethanol extracts of the seeds of Peganum harmala L.. Their structures including the absolute configuration were elucidated by using 1D and 2D NMR, and ECD calculation approaches. The cytotoxic activities of all isolated compounds were evaluated. 11 showed moderate cytotoxicity against PC-3 cells with an IC₅₀ value of 15.41?μM.     

Biochemical characterization of a novel 2-Cys peroxiredoxin from <Emphasis Type="Italic">Antrodia camphorata</Emphasis>

Peroxiredoxins (Prxs) play important roles in antioxidation and cell signaling. A gene encoding a novel 2-Cys Prx was identified based on sequence homology in an expressed sequence tag database of the Antrodia camphorata, a medicinal mushroom found only in Taiwan. The 2-Cys Prx cDNA (940 bp) encodes a protein of 188 amino acid residues with calculated molecular mass of 20,965 Da and a pI of 5.89. The coding region was subcloned into pAVD10, transformed into Escherichia coli, and expressed as a His-tagged fusion protein. The purified enzyme was characterized under various conditions. The Prx retained 68% activity after being heated at 60°C for 2 min. It was stable under a broad pH range from 5 to 11. The enzyme activity was slightly decreased in the presence of 1% sodium dodecyl sulfate. The enzyme was somewhat susceptible to chymotrypsin treatment but resistant to digestion by trypsin. Jenq-Kuen Huang, Chuian-Fu Ken, and Hui-Ming Huang contributed equally to this paper.     

丝棉木的引种及繁殖

丝棉木(Chorisia speciosa St.)是原产南美洲热带及亚热带地区的木棉科植物。落叶乔木,树干挺拔,树形优美,花期长,花朵大而绚丽,美国、秘鲁等国广泛用于道路及庭园绿化。一般认为只能通过种子繁殖。70年代末至80年代初我国广东和海南地区曾少量试种,表明植株长势及观赏效果甚佳。但一直不能自然结实,因而难     

当前我国植物资源利用研究中几个问题的探讨

在总结我国３０余年植物资源开发利用成果的基础上,论述该领域研究的深远意义和广阔前景;探讨研究对象与范围、多学科基础与合作;介绍了寻找新植物药源的途径;提出值得注意的问题与课题。为我国植物资源的开发利用研究提供某些借鉴和参考。     

虎纹镇痛活性肽在毕赤酵母中的分泌表达

虎纹镇痛活性肽HWAP-Ⅰ是从虎纹捕鸟蛛初毒中分离纯化,具有镇痛活性的多肽类神经毒素.为了在P.pastoris中高效分泌表达HWAP-Ⅰ,依照RT-PCR的结果,人工合成编码虎纹镇痛活性肽的基因片段,与酵母表达载体pPIC9K重组,构建表达质粒pPIC9K-HWAP-Ⅰ.转化GS115宿主菌后,筛选出整合型His⁺Mut^S表达菌株.经诱导培养后,SDS-聚丙烯酰胺凝胶电泳(PAGE)证明HWAP-Ⅰ在毕赤酵母中能有效分泌表达,产物的分子质量为4 ku左右,产量达80 mg/L.体外小鼠输精管阻断实验证实表达产物具有明显的生物活性.     

Factor Xa active site substrate specificity with substrate phage display and computational molecular modeling

Structural origin of substrate-enzyme recognition remains incompletely understood. In the model enzyme system of serine protease, canonical anti-parallel beta-structure substrate-enzyme complex is the predominant hypothesis for the substrate-enzyme interaction at the atomic level. We used factor Xa (fXa), a key serine protease of the coagulation system, as a model enzyme to test the canonical conformation hypothesis. More than 160 fXa-cleavable substrate phage variants were experimentally selected from three designed substrate phage display libraries. These substrate phage variants were sequenced and their specificities to the model enzyme were quantified with quantitative enzyme-linked immunosorbent assay for substrate phage-enzyme reaction kinetics. At least three substrate-enzyme recognition modes emerged from the experimental data as necessary to account for the sequence-dependent specificity of the model enzyme. Computational molecular models were constructed, with both energetics and pharmacophore criteria, for the substrate-enzyme complexes of several of the representative substrate peptide sequences. In contrast to the canonical conformation hypothesis, the binding modes of the substrates to the model enzyme varied according to the substrate peptide sequence, indicating that an ensemble of binding modes underlay the observed specificity of the model serine protease.     

从杨树菇中开发新型食品防腐剂的初步研究

本实验室通过对14株食用真菌的抑菌试验筛选,发现杨树菇具有极强的抑菌作用,且抑菌谱广,可以有效抑制细菌、酵母和部分霉菌。与不同浓度(0.05%、0.1%、0.2%、0.3% g/ml)山梨酸、苯甲酸抑菌能力相比,抑菌效果更为明显。以金黄色葡萄球菌为指示菌研究了其最适发酵条件及有效成分的热稳定性,结果表明:杨树菇的发酵周期为7-9d,发酵温度25℃,发酵的起始pH 6.0~7.0,发酵液装量为80~140 ml/500 ml三角瓶,接种量10%~15%(v/v);发酵液浓缩液经121℃、30 min湿热灭菌处理后仍具有很强的抑菌活性。杨树菇是一种具有开发前途的食用真菌。     

昆虫神经肽allatostatin的研究进展

昆虫神经肽咽侧体抑制激素(allatostatin,AST)是一类有几个至几十个氨基酸构成的小肽,它能通过咽侧体抑制保幼激素的合成,从而影响昆虫的生长发育及行为等一系列的生理过程,这使其极有可能成为一种新型控制害虫的杀虫剂。本文就咽侧体抑制激素的分布、功能、结构、代谢与降解进行综述,并探讨了AST的研究方法。