The 3/4- and 3/6-Subfamily Variants of α-Conotoxins GI and MI Exhibit Potent Inhibitory Activity against Muscular Nicotinic Acetylcholine Receptors

α-Conotoxins GI and MI belong to the 3/5 subfamily of α-conotoxins and potently inhibit muscular nicotinic acetylcholine receptors (nAChRs). To date, no 3/4- or 3/6-subfamily α-conotoxins have been reported to inhibit muscular nAChRs. In the present study, a series of new 3/4-, 3/6-, and 3/7-subfamily GI and MI variants were synthesized and functionally characterized by modifications of loop2. The results show that the 3/4-subfamily GI variant GI[∆8G]-II and the 3/6-subfamily variants GI[+13A], GI[+13R], and GI[+13K] displayed potent inhibition of muscular nAChRs expressed in Xenopus oocytes, with an IC₅₀ of 45.4–73.4 nM, similar to or slightly lower than that of wild-type GI (42.0 nM). The toxicity of these GI variants in mice appeared to be about a half to a quarter of that of wild-type GI. At the same time, the 3/7-subfamily GI variants showed significantly lower in vitro potency and toxicity. On the other hand, similar to the 3/6-subfamily GI variants, the 3/6-subfamily MI variants MI[+14R] and MI[+14K] were also active after the addition of a basic amino acid, Arg or Lys, in loop2, but the activity was not maintained for the 3/4-subfamily MI variant MI[∆9G]. Interestingly, the disulfide bond connectivity “C1–C4, C2–C3” in the 3/4-subfamily variant GI[∆8G]-II was significantly more potent than the “C1–C3, C2–C4” connectivity found in wild-type GI and MI, suggesting that disulfide bond connectivity is easily affected in the rigid 3/4-subfamily α-conotoxins and that the disulfide bonds significantly impact the variants’ function. This work is the first to demonstrate that 3/4- and 3/6-subfamily α-conotoxins potently inhibit muscular nAChRs, expanding our knowledge of α-conotoxins and providing new motifs for their further modifications.     

青蛤的种质、养殖及其开发利用研究进展

青蛤(Cyclina sinensis),俗称黑蛤,铁蛤,圆蛤和牛眼蛤等,隶属于瓣鳃纲（Lamellibranchia）、异齿亚纲 （Heterodonta）、帘蛤目（Venerida）、帘蛤科（Veneridae）,青蛤亚科（Cyclina）,广泛分布于朝鲜,日本和中国沿海的滩涂及河口地区。青蛤味道鲜美,具有较高的营养价值,且受重金属污染程度较低,是我国南北沿海重要的养殖品种。本文首次从青蛤的生物学与渔业生态学两大角度,系统的综述了迄今为止有关于青蛤的大部分研究,肯定前人研究成果的同时,也为今后有关青蛤的研究提供了研究方向,旨在为相关领域的科研和生产提供较为丰富的参考材料,增进人们对青蛤的认知。     

Progress in effect of TRPV1 on pathogenesis of asthma

Asthma is a common respiratory disease. In recent years, with the aggravation of environmental pollution, the morbidity and mortality of asthma have shown a significant upward trend. Recent literature provides evidence that transient receptor potential cation channel subfamily V member 1 (TRPV1) has both promoting and inhibitory effects on asthma and plays an important role in the development of asthma. Therefore, it is necessary to identify of TRPV1 receptor in asthma, in order to clarify the relationship between TRPV1 receptor and asthma, and to provide theoretical basis for drug research.     

高山竹子新分类群

本文介绍了竹亚科高山竹子马箭竹、木里箭竹、雷波玉山竹三个新种 ,大姚箭竹新分布和西藏箭竹新异名     

野生大豆AP2/RAV亚家族转录因子GsRAV3负调控拟南芥对ABA的敏感性

RAV亚家族蛋白包括1个AP2 DNA结合域和1个B3 DNA结合域。研究表明,GsRAV3是植物响应碱和ABA胁迫的重要调节因子。在碱和ABA处理下,野生大豆根系GsRAV3基因被诱导上调表达。与野生型相比,超量表达野生大豆GsRAV3的拟南芥在ABA胁迫下种子萌发状况和幼苗鲜重指标表现良好,对ABA敏感性降低。进一步研究表明,GsRAV3基因超量表达显著影响ABA合成和应答相关基因表达量。此外,GsRAV3定位于植物细胞核中,但在酵母细胞中未表现出明显的转录激活活性。综上所述,GsRAV3可能通过影响ABA合成及应答相关基因转录水平降低植物对外源ABA敏感性,表明GsRAV3在种子萌发和幼苗早期ABA信号传递过程中发挥重要作用。     

家蚕细胞色素P450基因Bmcyp6A8的克隆及序列与表达分析

昆虫细胞色素P450第6亚家族(CYP6)氧化酶在对异源有毒物质的代谢中具有重要作用。采用生物信息学方法获得与果蝇CYP6亚家族基因cyp6A8同源的家蚕cyp6A8基因序列,预测该基因的开放阅读框(ORF)为1572bp,编码523个氨基酸,推定的蛋白分子质量为61.52kD,等电点为8.17。以家蚕5龄第3天幼虫头部cDNA为模板,用设计的特异引物PCR扩增出一条约1500bp的条带,大小与家蚕cyp6A8基因的ORF预测值接近,命名为Bmcyp6A8基因(GenBank登录号:GQ241737)。同源性分析结果:Bmcyp6A8基因与野桑蚕cyp6AE8基因的相似性为93%;与棉铃虫cyp6AE12基因的相似性为57%;与人cyp3A43基因的相似性为48%。芯片数据分析显示Bmcyp6A8基因在家蚕5龄第3天幼虫的头部、表皮与中部丝腺前部高量表达,与家蚕CYP6亚家族的其它横向同源基因不同的是,只有该基因在中部丝腺前部表达,推测其具有功能特异性。     

PEBP家族基因在植物中功能的研究进展

主要介绍了磷脂酰乙醇胺结合蛋白(PEBP)家族的成员、进化关系以及各亚家族基因在植物中功能的研究进展。     

中国花天牛亚科分类研究

对我国花天牛亚科进行了广泛地分类研究。对花天牛亚科的分类历史、分类系统、起源、系统发育及常用的分类特征等进行了详细记叙,整理了我国花天牛亚科的全部种类共计283种和亚种,属于6族63属,其中发现了3个新种,6个中国新纪录,编制了族属鉴定检索表,并对花天牛亚科各阶元的学名全部拟订了中名。     

天牛总科雌性生殖器高级阶元分类

描述了天牛总科各科/亚科雌性生殖器的一般形态,并以雌性生殖器解剖特征,编制了天牛总科分科/亚科的分类检索表,讨论了各类群间的亲缘关系。