C端序列的删除对非出血重组蛇毒纤溶酶的影响

[目的]研究C端序列对非出血重组纤溶酶(rFⅡ)特异性、活性和热敏感性的影响.[方法]通过SOEing PCR方法构建删除C端序列的突变体,突变体和rFⅡ分别在P.pastoris中诱导表达.表达和纯化的蛋白用SDS-PAGE和Westeren blot进行鉴定.之后分析其生化特性.[结果]rFⅡ及突变体通过SDS-PAGE和Westeren blot得到证实.生化分析揭示:①突变体对显色底物N-(p-Tosyl)-Gly-Pro-Lys-pNA的催化效率(Kcat/Km)是rFⅡ的1.9倍;②突变体和rFⅡ对氧化的胰岛素B链拥有共同的优先裂解位点,可是在随后的裂解中开始展现差异;③突变体显示了更高的纤(原)活性;④热处理表明突变体相较r FⅡ对温度的增加更敏感;⑤通过圆二色谱测量,突变体的螺旋比例有所增加.[结论]删除的序列参与rFⅡ的特异性、活性和热敏感性,该序列可作为下一步优化的候选序列.     

Use of Fmoc-N-(2-hydroxy-4-methoxybenzyl) amino acids in peptide synthesis

The use of N, O-bisFmoc-N-(2-hydroxy-4-methoxybenzyl) amino acid derivatives in the synthesis of peptides with difficult sequences has already been described. With these amino acid derivatives the reversible protecting group 2-hydroxy-4-methoxybenzyl (Hmb) for the backbone amide bonds of peptide chains is introduced, and thus the aggregation due to hydrogen-bond interchain association is inhibited. This paper describes the synthesis and use of Fmoc-N-(2-hydroxy-4-methoxybenzyl)amino acid derivatives as an alternative means of introducing Hmb backbone protection. These new monoFmoc derivatives were obtained in higher yield than the bisFmoc derivatives. Coupling yields to the amino peptide resin were the same as those obtained with bisFmoc derivatives, under the TBTU/HOBt/DIEA conditions. We also compared different syntheses of a difficult peptide with the Fmoc approach [triple coupling, capping, use of chaotropic agents, backbone protection using monoFmoc (Hmb)Ala] and with optimized Boc chemistry. Both the backbone protection and optimized Boc chemistry approaches gave the desired product in excellent yield and purity. © Munksgaard 1997.     

腺嘌呤核苷酸载体的功能和表达与心力衰竭

腺嘌呤核苷酸载体（ANT）是一种位于线粒体内膜上的转运蛋白，它在组织细胞能量产生和消耗的耦联中起关键性作用。作者就ANT的功能和表达情况及其与心力衰竭之间的关系作一综述。     

薄层—质谱法测定绞股蓝皂甙A中的糖基顺序

用薄层—质谱法测定了绞股蓝皂甙XL Ⅲ中的糖及其顺序。方法快速、方便,可作为结构测试的手段。     

女孩雌激素受体基因6号内含子区域两个新SNPs位点报道

目的：在女性性早熟患儿中检测雌激素受体基因6号外显子及内含子基因序列可能存在的突变。方法：PCR扩增雌激素受体基因6号外显子及内含子，对扩增产物进行DNA序列分析。结果：在6号内含子一侧，发现两个100％连锁的单核苷酸多态性(SNPs)，分别为．53G—67A和53T—67G。结论：这一对单核苷酸多态性并不引起氨基酸的替代，与女孩性早熟的发生也无关，但是否和其他疾病有连锁关系尚待进一步探讨。     

聚合酶链反应产物特异性的阳性证实

以聚合酶链反应(PCR)法在mRNA水平检测T淋巴细胞受体α链可变区基因表达为例,介绍用~(32)P标记的人工合成寡核苷酸探针对PCR产物特异性作阳性证实的方法。该法以干琼脂糖凝胶作为支持物、相对较为简便和省财。用Ca探针以干凝胶作支持物的杂交结果,证实29个Vα基因的PCR扩增中物均为特异性的,放射自显影的带型与位置和溴乙锭染色所示完全吻合。     

2002年广东省H3N2亚型流感病毒流行的分子基础

目的 了解广东省2002年H3N2亚型流感病毒流行及抗原性变异情况。方法 用狗肾传代细胞(MDCK)和鸡胚进行流感病毒分离，用交叉血凝抑制实验对毒株进行抗原性分析；提取病毒RNA，用一步法RT-PCR扩增血凝素基因(H3A)，产物纯化后，并将其克隆到pMD18—T Vector，进行序列测定和分析。结果 2002年1-10月共获得流感病毒246株，其中H3N2亚型210株，占85．4％，H1N1亚型2株，占0．8％，B型34株，占13．8％；2002年流感流行的高峰是6月；抗原性分析显示，2002年广东省H3N2亚型流感病毒A／粤/236/2002和2001年流行株A／粤／448／2001以及目前国内代表株A／闽／151／2001的抗原比分别是5．6和4．0；其HAl区氨基酸序列和国际代表株A／悉尼／5／97同源性为94．2％，有19个氨基酸差异，其中发生在抗原决定族A、B、E上的有6个，受体结合部有3个。结论 2002年广东省流感病毒以H3N2亚型为主，其流行的分子基础是基因变异导致抗原性发生漂移。     

Schizophrenia susceptibility genes on chromosome 13q32

Schizophrenia is a complex mental disorder affecting approximately 1% of the general population worldwide.1 It has a high incidence in the general population, a poor prognosis and a poor outcome, in that it has become a major social problem. Family, twin, and adoption studies have clearly shown that a genetic component is quite likely to play an important role in determining susceptibility to schizophrenia. The genome-wide scan indicates that several chromosomal regions are linked to schizophrenia, some of which have been replicated independently including 6p21-24, 8p21-22, 13q14-33 and 22q11-12.2,3 This study was designed to detect two single nucleotide polymorphisms (SNPs) located in the 13q14-33 region, rs188608 at the STK24 locus and rs2892679 at the GPC6 locus, among Chinese population.