莲草直胸跳甲热激基因sHsp21在湖南和海南两个地理种群中的差异表达分析

sHsp21(小热激蛋白)是小热激蛋白家族的成员,在外界环境压力下能够被诱导,热激后能够调节蛋白质的折叠和保护细胞免受外界胁迫。本文研究了入侵杂草空心莲子草Alternanthera philoxeroides生防天敌莲草直胸跳甲的一个关键基因sHsp21,并对其进行热激诱导表达以及RACE全长扩增。获得全长cDNA 693 bp并完整的开放阅读框567 bp,共编码188个氨基酸。以30℃为对照,分别测定莲草直胸跳甲Agasicles hygrophila SelmanVogt长沙种群和海南种群在模拟夏季特定10∶00-14∶00时段36℃、39℃高温条件下sHsp21的表达量。连续热激6 d,每天4 h热激后取样,实时荧光定量PCR分析显示:湖南种群高温39℃和36℃诱导下sHsp21表达量都显著高于对照组30℃;海南种群36℃诱导下的表达量与对照组30℃差异不显著,39℃诱导下的表达量显著高于对照组30℃和36℃。结果表明,sHsp21在湖南和海南两地理种群不同耐热能力上起到重要作用,并且sHsp21的高表达可能对其虫体产生副作用,为下一步深入探究其生物学功能奠定了一定的基础。     

瑶药柑莲平喘胶囊治疗慢性支气管炎的临床研究

瑶药柑莲平喘胶囊是广西瑶族民间实地调查中所获的验方在西、中、瑶医基础理论指导下研制而成。方中主药余甘子经本实验室的实验结果证实余甘子叶总黄酮在体外有较好的广谱抗菌作用,对耐药性金黄色葡萄球菌尤为敏感,同时对肺气肿动物有较好的治疗作用。本方主要具有宣肺化痰,止咳平喘之功,主治肺气肿或支气管炎。症见:咳嗽气喘,痰多而粘,咯痰不爽,胸胀闷,舌苔厚腻,脉弦滑。属瑶医肺痨的范畴,俗称“忙哈”,“扯喉”;亦属中医“咳嗽”,“肺胀”,“喘证”的范畴。现将2004年11月~2006年2月临床观察的55例总结报告如下。1临床资料1·1一般资料选…     

Biochemical analysis of a papain-like protease isolated from the latex of Asclepias curassavica L.

Most of the species belonging to Asclepiadaceae family usually secrete an endogenous milk-like fluid in a network of laticifer cells in which sub-cellular organelles intensively synthesize proteins and secondary metabolites. A new papain-like endopeptidase （asclepain c-II） has been isolated and characterized from the latex extracted from petioles of Asclepias curassavica L. （Asclepiadaceae）. Asclepain c-II was the minor proteolytic component in the latex, but showed higher specific activity than asclepain c-I, the main active fraction previously studied. Both enzymes displayed quite distinct biochemical characteristics, confirming that they are different enzymes. Crude extract was purified by cation exchange chromatography （FPLC）. Two active fractions, homogeneous by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and mass spectrometry, were isolated. Asclepain c-II displayed a molecular mass of 23,590 Da, a pI higher than 9.3, maximum proteolytic activity at pH 9.4-10.2, and showed poor thermostability. The activity of asclepain c-II is inhibited by cysteine proteases inhibitors like E-64, but not by any other protease inhibitors such as 1,10-phenantrollne, phenyimethanesulfonyl fluoride, and pepstatine. The N-terminal sequence （LPSFVDWRQKGVVFPIRNQGQ CGSCWTFSA） showed a high similarity with those of other plant cysteine proteinases. When assayed on N-α-CBZ-amino acid-p-nitrophenyl esters, the enzyme exhibited higher preference for the glutamine derivative. Determinations of kinetic parameters were performed with N-α-CBZ-L-Gln-p-nitrophenyl ester as substrate： Km = 0.1634 mM, kcat = 121.48 s^-1, and kcat/Km = 7.4 ×10^5 s^-1/mM.     

云南锡兰莲属一新变种

云南锡兰莲属一新变种费勇（中国科学院昆明植物研究所，昆明６５０２０４）ＡＮＥＷＶＡＲＩＥＴＹＯＦＮＡＲＡＶＥＬＩＡＦＲＯＭＹＵＮＮＡＮＦｅｉＹｏｎｇ（ＫｕｎｍｉｎｇＩｎｓｔｉｔｕｔｅｏｆＢｏｔａｎｙ，ＣｈｉｎｅｓｅＡｃａｄｅｍｙｏｆＳｃｉｅｎｃｅｓ，...     

地球上最大的龅牙

<正>人类以龅牙为丑,动物却以龅牙为美!兔八哥的龅牙啃起萝卜真麻利,鼠小弟的龅牙就像小凿子,又快又锋利。海象那对长长的龅牙可以撬开坚硬的贝壳,还能在水面上爬行时当"拐杖"……可是在这广阔的星球上,究竟谁的龅牙最巨大、最震撼呢?答案即将为你揭晓……