Prion: the chameleon protein

From Creutzfeldt-Jakob disease (CJD) to variant CJD through Gerstmann-Str?ussler-Scheinker syndrome, kuru and fatal familial insomnia, the journey leading to current understanding of the basic aspects of human prion diseases has been full of unexpected, but often dramatic and always fascinating twists. Recent progress in modeling prion diseases and characterization of the various prion protein forms reveal that such a wide spectrum of the diseases is associated with the chameleon-like conformational features of prions.     

The corticotropin-releasing factor (CRF) family of peptides as local modulators of adrenal function

Corticotropin-releasing factor (CRF), also termed corticotropin-releasing hormone (CRH) or corticoliberin, is the major regulator of the adaptive response to internal or external stresses. An essential component of the adaptation mechanism is the adrenal gland. CRF regulates adrenal function indirectly through the central nervous system (CNS) via the hypothalamic-pituitary-adrenal (HPA) axis and via the autonomic nervous system by way of locus coeruleus (LC) in the brain stem. Accumulating evidence suggests that CRF and its related peptides also affect the adrenals directly, i.e. not through the CNS but from within the adrenal gland where they form paracrine regulatory loops. Indeed, CRF and its related peptides, the urocortins (UCNs: UCN1, UCN2 and UCN3), their receptors CRF type 1 (CRF₁) and 2 (CRF₂) as well as the endogenous pseudo-receptor CRF-binding protein (CRF-BP) are all expressed in adrenal cortical, medullary chromaffin and resident immune cells. The intra-adrenal CRF-based regulatory system is complex and depends on the balance between the local concentration of CRF ligands and the availability of their receptors. Received 19 December 2006; received after revision 20 February 2007; accepted 26 March 2007     

基于投票表决特征融合的蛋白质结构类预测

根据氨基酸的物化特性,基于氨基酸组成成分与氨基酸残基指数自相关函数相结合特征提取法,从非同源蛋白质序列中提取7个特征集(COMP、FINA、MAXF、NAKH、BIOV、OOBM、RICJ),采用有先验知识的投票表决特征融合算法融合这7个特征集,对蛋白质结构类进行预测.结果表明,投票表决融合算法的预测总精度及每一类别的预测精度与7个特征集相比较均有不同程度的提高,说明投票表决融合算法在一定程度上能较多地反映蛋白质的空间结构信息.     

基于蛋白质药效团匹配的化合物功能预测

采用了基于蛋白质药效团匹配的化合物评价策略.以配体分子为提问结构对相应数据库进行反向筛选,根据筛选结果可以得到提问分子在人体内可能的作用受体,并以此为依据进行分子结构改造,以加强配体分子的结合专一性.选取环氧合酶2的专一性抑制剂Rofecoxib按照药效团匹配方法进行反向筛选评价,结果与实验事实吻合,并且提出了一个Rofecoxib的潜在靶标.此方法为未知化合物的功能预测和"老药新用"提供了一种新方法、新思路.     

利用高压吸收光谱研究蛋白质结构的变化

蛋白质的结构会在压强的作用下发生变化,结构的变化会引起吸收光谱的变化。对血红素类蛋白质,这种变化主要体现在第III带,即通过观察测量第III带吸收谱的强度可以将蛋白质结构变化与压强联系起来。研究了肌红蛋白在水和甘油与水的混合液中两种情况下的第III带及Q带吸收光谱随压强(最高至7kbar)的变化关系,表明在一定范围内(水溶液中约小于2.5k-bar,甘油与水的混合液中约小于4.5kbar),Fe2 原子与血红素辅基的间距随压强的增加而线性减小;当压强超过某值后,第III带强度发生了跃迁,蛋白质发生了明显的变性。继续增加压强,肌红蛋白溶液的吸收谱则失去了肌红蛋白的基本特征。     

高产高蛋白优质紫稻新品系的选育

１９８９￣１９９５年应用系统选育、纯化去杂和加代繁殖等育种方法，培育出紫稻新品系：华黑０１、华黑０２。其稻谷平均产量分别为７３４５．５±４６９．５ｋｇ／ｈｍ＾２，６８２８．０±２７６．０ｋｇ／ｈｍ＾２；稻米蛋白质含量分别为１３．４１±０．３７％、１３．１５±０．５４％。８种必需氨基酸中有５￣６种超过ＦＡＤ／ＷＨＯ建议的理想蛋白质标准。具较好的口感和营养品质。     

凯氏定氮法测定松杉灵芝子实体水溶性多糖中蛋白质含量

从松杉灵芝(Ganoderma tsugae Murr)子实体中提取出水溶性粗多糖FA,进一步纯化得FA2,以凯氏定氮法测定其中蛋白质含量,分别为19.03%和4.07%.     

DpNPV多角体蛋白拉曼光谱的研究

研究了马尾松毛虫核型多角体病毒多角体蛋白的拉曼光谱。结果表明，ＤｐＮＰＶ多角体蛋白的二级结构主要为α螺旋和无规卷曲，后者含有大量的β回析，多角体蛋白的侧链Ｃ－Ｃ－Ｓ－Ｓ－Ｃ－Ｃ－构型为反式－扭曲－反式。     

检测糖化血清蛋白的试剂及方法改进

介绍三种可作为测定糖化血清蛋白的标准物，即果糖林，果糖哌啶，α－Ｄ葡萄糖五乙酸酯，并比较了它们的优缺点，其中后两种作为检测糖化血清蛋白的标准物，尚未未见其它文献报道；通常是色剂氯化硝基四氮唑蓝试液在存放过程中常常出现沉淀，作者通过ＩＲ和薄层色谱分析对该沉淀物进行了表征，同时对ＮＢＴ的配制和储存方法进行了改进，克服了ＮＢＴ在存放过程中出现沉淀的现象。