SELEX技术

 

这个技术就是一个文库技术(library)加一套筛选技术(bio-panning)。当然，SELEX技术仅仅是分子进化工程的一种而已。实际上，理解了文库技术和筛选技术，不仅selex理解了，其他热门技术如Phage display等等也懂了。

我知道的著作中，赵康等主编的Frontiers of Biotechnology and Pharmaceuticals 第三卷（只有英文版）是值得一读的。其中的一些作者都是亲自做这个领域的大多数是海外华人科学家。

在RNA领域的分子进化工程我知道这么几种： （1）SELEX (2)Ribozyme （指从文库中筛出来的，不是天然的，DNAzyme也是靠分子进化筛出来的 ）(3)核糖体表面展示。

另外还要进入一个术语 aptamers, 这篇用aptamer搜得的是免费看得
http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=14500841

Selective inhibitory DNA aptamers of the human RNase H1

从药学的角度看，SELEX技术使得要筛选的化合物库库容可以很大，传统化合物库库容小，是药学界面临的重要危机之一。SELEX技术就相当于化学上的“组合化学”。

现在补充上我老板的美国博士生的论文上的图。先建立随机文库－－－与ＲＮＡ病毒结合的ＲＮＡ－－－反转录，扩展－－－改变“进化压力”，多轮筛选－－挑出活性最强的，就是抗病毒ＲＮＡ

现在已经建立了aptamer database, 网址为
http://aptamer.icmb.utexas.edu/

关于这个文库的介绍见
http://www3.oup.co.uk/nar/database/summary/411

Aptamer Database
NAR Molecular Biology Database Collection entry number 411

Database Description
Aptamers are DNA or RNA molecules that have been selected from random pools based on theirability to bind ligands such as small organic or inorganic compounds, peptides, proteins, and even entire organisms. Like antibodies, aptamers have high affinity and specificity for their targets, and thus have many potential uses in medicine and technology. The Aptamer Database is a comprehensive, annotated repository for information about aptamers and in vitro selection experiments. It is useful not only as a compendium of the research that has been carried out and the sequences that are known, but as a unique resource for theoretical and evolutionary biologists who wish to explore the distribution and relationships between functional nucleic acids. The database is available via the web at http://aptamer.icmb.utexas.edu.

查找了一下NAR的数据库名单（http://www3.oup.co.uk/nar/database/c）又找到一个SELEX数据库叫SELEXdb
可以免费看到网页 http://www3.oup.co.uk/nar/database/summary/246
文摘见 http://nar.oupjournals.org/cgi/content/abstract/30/1/195

(自己译的，不通顺的地方看原文吧)
SELEX_DB是个在线资源，既包括对DNA/RNA寡聚物（Aptamers有人译为适合体，感觉不好，没有通用的译法，我译为适配子）体外筛选的实验数据，也包含识别这些寡聚物的Jawa程序（applets）。由于体外实验数据明显是系统依赖性的，新发布的SELEX_DB已经由存储试验设计SYSTEM数据库进行了补充。另外，用于体外选择数据来注释基因组DNA的识别（用）applets（Jawa程序）程序包，SELEX_TOOLS, 已同时通过测试数据库CROSS_TEST的交叉验证。SELEX_TOOLS能用来辨别通过随机DNA进行体外选择时，与之相关的(自然的或其它)位点-我们不期然地发现，识别准确性随着训练（组）和蛋白质结合序列测试组间同源性的增长而增加。对于自然位点，识别准确性低于最接近蛋白质同源区的准确性高于远同源区和结合共同位点的非同源蛋白。当前的SELEX_DB可以通过这个网站获得：
http://wwwmgs.bionet.nsc.ru/mgs/systems/selex/.

Abstract
SELEX_DB is an online resource containing both the experimental data on in vitro selected DNA/RNA oligomers (aptamers) and the applets for recognition of these oligomers. Since in vitro experimental data are evidently system-dependent, the new release of the SELEX_DB has been supplemented by the database SYSTEM storing the experimental design. In addition, the recognition applet package, SELEX_TOOLS, applying in vitro selected data to annotation of the genome DNA, is accompanied by the cross-validation test database CROSS_TEST discriminating the sites (natural or other) related to in vitro selected sites out of random DNA. By cross-validation testing, we have unexpectedly observed that the recognition accuracy increases with the growth of homology between the training and test sets of protein binding sequences. For natural sites, the recognition accuracy was lower than that for the nearest protein homologs and higher than that for distant homologs and non-homologous proteins binding the common site. The current SELEX_DB release is available at http://wwwmgs.bionet.nsc.ru/mgs/systems/selex/.