The orientational preferences of backbones of proteins

The orientation between the backbone residues of proteins is defined based on the local configurations and the corresponding preferences are analyzed by statistics.It is found that all the residue pairs have some specific preferences of orientations.The statistical analysis is mainly concen-trated in the orientational distributions for two kinds of groupings of residues based on the hydrophobicity and secondary structural features.The statistics for such two types of groupings shows different orienta-tional preferences.It is found that for the former grouping the orientational preference is rather weak, while for the later a kind of strong orientational pref-erences.This suggests that the formation of local structures and of secondary structures are highly related to the orientational preferences.     

A Statistical Analysis of Protein—Protein Interaction with Knowledge—Based Potential at Residue Level

Protein-protein recognition is an important step in biological processes, which still largely remains elusive. The inter-residue contact potential, CPij, describes the propensity of contact between two types of residue. In this study, several different CPij variants were examined with the objective of discriminating the binding potential of surface pairs. Using solvent mediated inter-molecule contact potential (SM-IMCPij), an evaluation model was deduced and tested. Using the evaluation model it was found that the SM-IMCPij gives a better performance than either residue mediated IMCPij(RM-IMCPij) or folding-residue contact potential (FCPij). The results suggest that the evaluation model provides a fast, effective, and discriminative method for the evaluation of proposed binding interfaces.     

Learning to Predict in Complex Biological Domains

1 Introduction1 Bioinformatics is a rapidly expanding field involving a significant contribution from the data mining community. Many different problems are grouped into the general category of bioinformatics, including protein secondary structure prediction, drug discovery, DNA microarray analysis, gene prediction and genome analysis [17]. In this paper, we focus on two particular problems in which data mining can contribute: drug discovery and protein secondary structure prediction. Both …     

ω-芋螺毒素 MVIIA/虎纹捕鸟蛛毒素-I嵌合体HM-1227的合成及活性测定

用Fmoc固相多肽合成的方法手工合成了一种ω-芋螺毒素MVIIA和纹捕鸟蛛毒素-I的嵌合体HM-1227，经过RP-HPLC纯化和氧化复性，小鼠隔神经-隔肌标本的阻断实验显示此嵌合体能实现二硫键完全配对与稳定折叠并具有弱的神经毒活性。实验结果表明，ω-CtxMVIIA和HWTX-I的分子框架稳定，部分序列交换后仍能实现二硫键配对与折叠，说明该结构模体可以作为蛋白质工程的分子框架。     

A Co—expression System Based on Phage and Phagemid to Select Cognate Antibody—antigen Pairs in vivo

A modified selectively-infective phage(SIP) is developed to facilitate the selection of interacting antibody-antigen paris from a large single-chan antibody(scFv)library in vivo.The system is constructed with a modified helper phage M13KO7 and phagemid pCANTAB 5E.The antigen fused to the C-terminal of N1-N2 domain and the scFv to the N-terminal of CT domain of the gIIIp of filamentous phage are encoded on the phage and phagemid vectors respectively.The phages produced by co-transformants restore infectivity via interaction between antigen and antibody fusions in the cell periplasm.In a model system,the scFv fragment of the anti-hemagglutinin 17/9 antibody and its corresponding antigen are detected in the presence of a 10^5 fold excess of a non-interacting cotrol paris,which demonstrates this system to be very sensitive and facile to screen a large single-chain antibody library.     

利用农业废弃物微生物共发酵制取蛋白质的研究

采用宇佐美曲霉等4种真菌与热带假丝等酵母菌对农业废弃物秸秆进行混合发酵制取蛋白，产物中必需氨基酸含量高于联合国粮农组织(FAO)规定标准，蛋白含量超过玉米和小麦，可作为动物的蛋白饲料。     

生物机与蛋白质

对于体内最重要的两类生物分子--核酸和蛋白质,科学家们已经了解到:核酸有遗传信息而无催化作用;而蛋白质有催化作用反而没有遗传信息.核酸中的脱氧核糖核酸在不同状态下,可产生有信息和无信息的变化,这就激起了科学家们研制生物电子元件的灵感--生物计算机.     

2813条全长人类新基因编码蛋白质的功能预测

用生物信息学序列分析方法对联合基因科技（集团）公司2813条全长人类新基因编码的蛋白质进行了功能预测,由WU－BLASTP核酸 列相似性分析结果表明P值小于le-20的基因合计有466条,占总分析基因的16．57％,P值在le-10以下的基因合计有565条,占总分析基因的20．09％,由蛋白质结构域分析结果表明,含PROSITE Pattern的基因有520条,代表了107种pattern;含PROSITE profile的基因有333条,代表了200种profile;含PFAM结构域的基因有457条,代表了241个family; 含PRINTS的家族指纹1型（class1)的基因有128条,指纹2型（class2) 的有18条,总数为146条,代表了45种家族指纹,由特殊结构分析表明,跨膜蛋白470条,分泌蛋白677条,Coliled-coil蛋白228条,Helix-turn-helix蛋白73条。     

人类H5N1型病毒的毒因

A型禽流感病毒的H5N1毒株,自1997年在东南亚始发以来,已致90多人死亡,受感染者的死亡率约为50％。如今这些病毒正从亚洲向欧洲和非洲扩散,当它一旦获得了在人体间传播的能力,就会造成全球流感大爆发的严重后果。所以研究人员始终把识别H5N1病毒的分子基础作为研究重点。已有的研究结果显示,各种生物的A型流感病毒的毒性与多种基因有关;因而怀疑H5N1病毒在人体中的毒力与其所编码的几种蛋白质有关。2006年3月17日出版的《自然》杂志上,奥本奥尔（Obenauer）等人发表的文章中指出,H5N1的毒性是由以前从未注意到的,病毒所编码的一种非结构蛋白质NS1的氨基酸序列所致。