6-磺基脱氧葡萄糖甘油二酯对脂质体的稳定作用

 ６┐磺基脱氧葡萄糖甘油二酯对脂质体的稳定作用＊韩兴李刚（北京医科大学生物物理系,北京１０００８３ＴｈｅＳｔａｂｉｌｉｚｉｎｇＥｆｆｅｃｔｏｆＳｕｌｐｈｏｑｕｉｎｏｖｏｓｙｌｄｉａｃｙｌ┐ｇｌｙｃｅｒｏｌｏｎＬｉｐｏｓｏｍｅｓＨａｎＸｉｎｇＬｉＧａｎｇ...     

在长江沙洲上搁浅的中华白海豚

在长江沙洲上搁浅的中华白海豚ＳＴＲＡＮＤＩＮＧＯＦＡＮＩＮＤＯ┐ＰＡＣＩＦＩＣＨＵＭＰ┐ＢＡＣＫＥＤＤＯＬＰ┐ＨＩＮＯＮＡＳＡＮＤＢＡＮＫＩＮＴＨＥＹＡＮＧＴＺＥＲＩＶＥＲ中华白海豚（Ｓｏｕｓａｃｈｉｎｅｎｓｉｓ,Ｏｓｂｅｃｋ）分布在西太平洋和印度...     

一种新的微量蛋白电泳及超敏感染色技术(英文)

ＡＮｅｗＴｅｃｈｎｉｑｕｅｏｆＭｉｃｒｏｐｒｏｔｅｉｎｅｌｅｃｔｒｏｐｈｏｒｅｓｉｓａｎｄＵｌｔｒａｓｅｎｓｉｔｉｖｅＳｔａｉｎｉｎｇ１ＰＡＮＧＧｕａｎｇｃｈａｎｇ２,ＺＨＡＯＤｏｎｇｘｕ３,ＹＡＮＧＸｉｎｌｉｎＣＨＥＮＧｕａｎｇｗｅｎ...     

蛋白质间相互作用技术的研究近况

蛋白质间相互作用技术的研究近况黄翠芬叶棋浓（军事医学科学院生物工程研究所,北京１００８５０关键词：蛋白质,相互作用,技术ＲｅｃｅｎｔＡｄｖａｎｃｅｓｉｎｔｈｅＴｅｃｈｎｉｑｕｅｓｏｆＰｒｏｔｅｉｎ┐ＰｒｏｔｅｉｎＩｎｔｅｒａｃｔｉｏｎｓＨｕａｎｇＣｕ...     

质膜H~+-ATPase磷酸化对其活性的调节

 质膜Ｈ＋┐ＡＴＰａｓｅ磷酸化对其活性的调节＊凌启阆向左云刘华尚克进（南开大学生物化学及分子生物学系,天津３０００７１）ＲｅｇｕｌａｔｉｏｎｏｆＰＭＨ＋┐ＡＴＰａｓｅＡｃｔｉｖｉｔｙｂｙＩｔｓＰｈｏｓｐｈｏｒｙｌａｔｉｏｎＬｉｎｇＱｉ－ＬａｎｇＸｉａｎ...     

桐麦间作对小麦生理生长的影响

桐麦间作对小麦生理生长的影响＊景元书（南京气象学院,２１００４４）吴运英（中国林科院林业研究所,北京１０００９１）ＴｈｅＩｎｆｌｕｅｎｃｅｓｏｆｐａｕｌｏｗｎｉａ┐ｗｈｅａｔＩｎｔｅｒｃｒｏｐｐｉｎｇｏｎＰｈｙｓｉｏｌｏｇｉｃａｌＲｅａｃｔｉｏｎａｎ...     

棉蚜田间种群特定死亡率分析

棉蚜田间种群特定死亡率分析戈峰丁岩钦（中国科学院动物研究所,北京１０００８０）ＡｎａｌｙｓｉｓｏｆｔｈｅＴｉｍｅ┐ｓｐｅｃｉｆｉｃＭｏｒｔａｌｉｔｙｏｆＣｏｔｔｏｎＡｐｈｉｄ（Ａｐｈｉｓｇｏｓｓｙｐü）Ｐｏｐｕｌａｔｉｏｎ．ＧｅＦｅｎｇ,ＤｉｎｇＹａ...     

白鲜皮中白鲜碱含量测定

白鲜皮中白鲜碱含量测定朱丹妮徐强邱南生（中国药科大学,南京２１００３８）ＴｈｅｑｕａｎｔｉｔａｔｉｖｅｄｅｔｅｒｍｉｎａｔｉｏｎｏｆｄｉｃｔａｍｉｎｅｉｎｒｏｏｔｂａｒｋｏｆＤｉｃｔａｍｎｕｓｄａｓｙｃａｒｐｕｓＴｕｒｃｚ．ＺｈｕＤａｎＮｉ,Ｘｕ...     

甜菜纤维的制备及其性质

甜菜纤维的制备及其性质樊志和周人纲王占武李晓芝韩炜（河北省农林科学院农业物理生理生化研究所,石家庄０５００５１）Ａｐｒａｃｔｉｃａｌｐｒｅｐａｒａｔｉｏｎａｎｄｃｈａｒａｃｔｅｒｉｚａｔｉｏｎｏｆｄｉｅｔａｒｙｆｉｂｅｒｆｒｏｍｓｕｇａｒ┐ｂｅｅｔｐ...     

三峡工程与江汉平原农业持续发展

三峡工程与江汉平原农业持续发展朱俊林（湖北大学生态学研究所,武汉４３００６２）ＩｎｆｌｕｅｎｃｅｓｏｆｔｈｅＴｈｒｅｅ＿ＧｏｒｇｅＰｒｏｊｅｃｔｏｎｔｈｅＡｇｒｉｃｕｌｔｕｒｅｉｎＪｉａｎｇｈａｎＰｌａｉｎＡｒｅａａｎｄｔｈｅＡ┐ｇｒｉｃｕｌｔｕｒａ...     

srhM-CSFR在昆虫细胞中的表达及其配基结合活性分析

从人胎盘中提取总 RNA,利用 RT- PCR技术扩增出巨噬细胞集落刺激因子受体 ( M-CSFR)胞外区的、具有全部配基结合活性区域的前三个免疫球样蛋白结构域的 DNA,将其克隆到杆状病毒载体 pbluebac4.5中 ,与杆状病毒 DNA一同转导昆虫细胞 Sf9.经过 2轮筛选 ,获得了纯化的重组病毒 ,再用重组病毒感染昆虫细胞 ,Western印迹检测证明 srh M- CSFR得到了表达 ,它是分泌到上清液中的糖基化蛋白 .Western印迹分析了不同时间点的 srh M- CSFR表达情况 ,结果表明 srh M- CSFR的表达在 96～ 1 2 0 h时达到最大 .srh M- CSFR的产量约为 1 mg/L,EIA法进行配基结合活性分析表明 ,srh M- CSFR与 M- CSF结合的解离常数为 5nmol/L.     

Solution structure of the Mu end DNA-binding ibeta subdomain of phage Mu transposase: modular DNA recognition by two tethered domains.

The phage Mu transposase (MuA) binds to the ends of the Mu genome during the assembly of higher order nucleoprotein complexes. We investigate the structure and function of the MuA end-binding domain (Ibetagamma). The three-dimensional solution structure of the Ibeta subdomain (residues 77-174) has been determined using multidimensional NMR spectroscopy. It comprises five alpha-helices, including a helix-turn-helix (HTH) DNA-binding motif formed by helices 3 and 4, and can be subdivided into two interacting structural elements. The structure has an elongated disc-like appearance from which protrudes the recognition helix of the HTH motif. The topology of helices 2-4 is very similar to that of helices 1-3 of the previously determined solution structure of the MuA Igamma subdomain and to that of the homeodomain family of HTH DNA-binding proteins. We show that each of the two subdomains binds to one half of the 22 bp recognition sequence, Ibeta to the more conserved Mu end distal half (beta subsite) and Igamma to the Mu end proximal half (gamma subsite) of the consensus Mu end-binding site. The complete Ibetagamma domain binds the recognition sequence with a 100- to 1000-fold higher affinity than the two subdomains independently, indicating a cooperative effect. Our results show that the Mu end DNA-binding domain of MuA has a modular organization, with each module acting on a specific part of the 22 bp binding site. Based on the present binding data and the structures of the Ibeta and Igamma subdomains, a model for the interaction of the complete Ibetagamma domain with DNA is proposed.     

Domain B of ARS307 contains two functional elements and contributes to chromosomal replication origin function.

ARS307 is highly active as a replication origin in its native location on chromosome III of Saccharomyces cerevisiae. Its ability to confer autonomous replication activity on plasmids requires the presence of an 11-bp autonomously replicating sequence (ARS) consensus sequence (ACS), which is also required for chromosomal origin function, as well as approximately 100 bp of sequence flanking the ACS called domain B. To further define the sequences required for ARS function, a linker substitution mutagenesis of domain B was carried out. The mutations defined two sequences, B1 and B2, that contribute to ARS activity. Therefore, like ARS1, domain B of ARS307 is composed of functional subdomains. Constructs carrying mutations in the B1 element were used to replace the chromosomal copy of ARS307. These mutations caused a reduction in chromosomal origin activity, demonstrating that the B1 element is required for efficient chromosomal origin function.     

皖南尖吻蝮蛇毒中类去整合蛋白/富含半胱氨酸两结构域cDNA的克隆和表达

为了探讨出血毒金属蛋白酶结构功能关系 ,通过 RT- PCR方法 ,从皖南尖吻蝮蛇( Agkistrodon acutus)毒腺总 RNA中扩增得到编码 P- 型出血毒金属蛋白酶的完整类去整合蛋白和富含半胱氨酸两个结构域 c DNA( AA/DC) .它全长 964bp的 c DNA,开放阅读框架编码 2 1 6个氨基酸残基 ,序列比较分析表明它同来自 Bothrops jararaca的 jararhagin- C、来自 Crotalus atrox的 catrocollastatin- C有很高的同源性 .在类去整合蛋白结构域中 ,Ser- Glu- Cys- Asp( SECD)代替了去整合蛋白中相应部位的 Arg- Gly- Asp( RGD)三肽序列 .将编码区基因克隆入 p GEX- 2 T载体中 ,转化大肠杆菌 TG- 1 ,用 IPTG诱导表达 ,表达产物具有抑制胶原诱导的血小板凝集活性 ,但不抑制ADP诱导的血小板凝集 .该研究为进一步阐述蛇毒金属蛋白酶结构功能关系和药物开发奠定了基础 .     

C-Mannosylation of MUC5AC and MUC5B Cys subdomains

We expressed recombinant Cys subdomains in COS-7 cells to examine the role of this highly conserved protein domain in mucin biosynthesis. The entire Cys1 and Cys5 and Cys1 and Cys3 subdomains in MUC5AC and MUC5B, respectively, each with six carboxyl terminal histidine residues, were pulse-labeled with [(35)S]cysteine/methionine, and the labeled proteins were examined in the culture medium. Under nonreducing conditions, secreted Cys subdomains were monomers, indicating the absence of interchain disulfide bonds. Cross-linking studies suggested the domains are able to interact through very weak noncovalent interactions. Though the domains had apparent M(r) consistent with the absence of N- and O-glycans, they could be purified with mannose-specific lectins. Lectin binding was prevented by mutation of the first tryptophan residue in the putative C-mannosylation acceptor motif WXXW, indicating that C-mannosylation is responsible for lectin binding. As judged by pulse-chase experiments, C-mannosylation occurred very early during the domain biosynthesis, likely in the endoplasmic reticulum (ER). Mutation of the WXXW motif or expression of the unmutated domain in CHO-Lec35.1 cells, a C-mannosylation-defective cell line, resulted in reduced secretion of the corresponding Cys subdomains. Live cell imaging of green fluorescent protein fused to the Cys subdomains clearly revealed increased presence of Cys subdomains in the ER of CHO-Lec35.1 cells when compared to the same domains expressed in CHO-K1 cells. Considered together, these studies suggest that the Cys subdomains of MUC5AC and MUC5B are C-mannosylated in their respective WXXW motifs. C-mannosylation is likely required for proper folding of the Cys subdomains and/or for some aspect of ER export during mucin biosynthesis.     

Microdissection of M chromosome in Vicia faba and its library construction]

Microdissection and microcloning technique was employed to construct the library of M chromosome in Vicia faba. The M chromosomes were microdissected with a micromanipulator and were put into a 0.5 ml Eppendorf tube, then digested with Sau3A. Sau3A linker adaptors were ligated to the end of chromosome DNA fragments, and two rounds of PCR were carried out with one chain of linker adaptor as the primer. The PCR products ranged in size from 300 base pair (bp) to 3000 bp with predominant fragments from 500 bp to 1500 bp. Southern hybridization analysis confirmed that PCR products originated from Vicia faba genome. The second round PCR products were cloned and about 102,000 recombinants were obtained. 118 recombinants were selected randomly for analysis. The inserts ranged in size from 150 bp to 3000 bp with an average of 690 bp. Dot blot was carried out for 100 clones with DIG labeled Vicia faba genome DNA as probes. The result revealed that 51% were low and unique copy sequences, 49% were repetitive sequences. M chromosome DNA library has not been reported before.     

Identification of members of Mycobacterium avium species by Accu-Probes, serotyping, and single IS900, IS901, IS1245 and IS901-flanking region PCR with internal standards

From Mycobacterium avium species Mycobacterium avium subsp. paratuberculosis (n=961), Mycobacterium a. avium (n=677), Mycobacterium a. silvaticum (n=5), and Mycobacterium a. hominissuis (n=1566) were examined, and from Mycobacterium tuberculosis complex M. tuberculosis (n=2), Mycobacterium bovis (n=13), M. bovis BCG (n=4), and Mycobacterium caprae (n=10) were examined. From other mycobacterial species Mycobacterium intracellulare (n=60) and atypical mycobacteria (n=256) including Mycobacterium fortuitum, Mycobacterium chelonae, Mycobacterium scrofulaceum, Mycobacterium gastri and other species of conditionally pathogenic mycobacteria were analysed. The internal standard molecules corresponding to insertion sequences IS900, IS901, IS1245, and flanking region (FR300) of IS901 were produced by PCR of alfalfa genome segment and inserted into plasmid vector. The resulting recombinant plasmid molecules were used as internal standards in coamplification with a total of 4729 mycobacterial collection strains and field isolates between 1996 and 2003. The size differences between amplicons obtained from IS900 (258 bp), IS901 (1108 bp), IS1245 (427 bp), and FR300 (300 bp) and from corresponding internal standard molecules ISIS900 (591 bp), ISIS901 (1 336 bp), ISIS1245 (583 bp), and IS901 flanking region of 300 bp ISFR300 (488 bp), respectively, allowed easy discrimination. The internal amplicons were visible by naked aye on agarose gel when 10(1), 10(3), 10(2), and 10(2) molecules for ISIS900, ISIS901, ISIS1245, and ISFR300 were used in the PCR, respectively, when no bacterial DNA was added to the reaction. The system was tested to define the amount of internal standards that could be used in the PCR without affecting the amplification of the specific segment. Non-specific amplifications were observed in M. fortuitum with IS1245 PCR and mixed infections with M. a. avium and M. a. hominissuis from pigs and cattle were found. PCR results of typing were compared with serotyping and Accu-Probes analyses in selected field isolates.