Bioinformatics in the post-genomic age

The sequencing of several genomes, including the human genome, has provided a vast amount of information which must be exploited if new drugs are to be provided. Bioinformatics is essentially the science of taking this and other biological information and applying advanced IT techniques to it so as to identify protein targets and therefore suitable drug candidates. Databases, software and research and development tools are all being created with a view to efficient search and interrogation.The author, in emphasising the need for obtaining appropriate monopoly protection, highlights the problems associated with the patenting of computer program related patents and refers to database rights as an alternative form of protection.     

RNA干扰SW480细胞HIF-1α双向凝胶电泳中横向拖尾的消除及条件的优化

目的建立RNA干扰结肠癌SW480细胞系,并对缺氧诱导因子-1α(HIF-1α)双向凝胶电泳中的多个关键步骤进行优化,以消除横向拖尾。方法以携带针对HIF-1α两条干扰片段的pGenesil-11质粒转染SW480细胞,沉默HIF-1α。对双向凝胶电泳中样品裂解液、样品的处理方式、上样量及电泳条件等进行优化。结果转染第7天RNA干扰效果最好。RNA干扰后,SW480细胞蛋白用含有硫脲的裂解液B进行提取,以样品制备方法A进行处理后,上样200μg蛋白,延长除盐时间,聚焦50000伏小时,得到的双向凝胶电泳图基本没有横向拖尾,分离蛋白点1288±15。结论已成功建立了RNA干扰结肠癌SW480细胞系;优化的双向凝胶电泳可有效消除横向拖尾,为进一步分析、鉴定和寻找与疾病相关的蛋白质奠定了基础。     

Analysis of the human testis proteome by mass spectrometry and bioinformatics

The testis is a unique organ responsible for sperm production and androgen secretion in men. To analyze the human testis proteome on a large scale, 1-D SDS-PAGE and RP-LC-MS/MS were applied and 1430 proteins in the human testis were identified. Both the false-positive rate of peptides and protein identification confidence scores were calculated in the present study. Subsequent bioinformatics analysis of the human testis proteome revealed 39 testis-specific proteins which may be important for testis functions. And a large family of proteins were identified possibly involved in alternative splicing, which may also be involved in testis-specific splicing events and explain why splicing is so prevalent in the testis. Compared with the studies on brain proteome, researches on the testis proteome is still very limited. Studies of these proteins will give a better understanding on the function of the testis. Moreover, this large-scale identification of testis proteins in humans could serve as a reference for future studies on the mechanisms underlying male infertility, searching for potential contraceptive targets, and developing new treatments for testis cancer.     

Western blotting revisited: Critical perusal of underappreciated technical issues

The most commonly used semiquantitative analysis of protein expression still employs protein separation by denaturing SDS-PAGE with subsequent Western blotting and quantification of the resulting ODs of bands visualized with specific antibodies. However, many questions regarding this procedure are usually ignored, although still in need of answering: Does isolation or separation procedure harm the integrity or affect modifications (e.g., phosphorylation) of the protein of interest? Does denaturation reduce binding of antibodies used for detection? Should denaturation be performed or should a native gel be run? How can artificial degradations or aggregations be distinguished from biological relevant ones? If the antibody detects multiple bands (which is not uncommon), which one(s) should be taken into account for quantification and why? Which loading control protein should be chosen and is it really “housekeeping” and how can this be verified? Is the image acquisition system linear and does it come with a sufficient dynamic range? How to account and control for background staining? This article is intended to address these questions and raise the readers awareness to possible Western blot alternatives in the attempt of minimizing possible pitfalls that might loom anywhere from protein isolation to acquisition of final quantitative data.