奇妙的核酸世界

The Wonderland of Nucleic Acids

周三和(Shan-Ho Chou)

《化學》 58卷4期 (2000/12) Pp. 621-634

https://doi.org/10.6623/chem.2000064

摘要

華生－克里搭核酸雙螺旋結構的提出，可說是近代生物學研究最重要的貢獻之一。利用G．C及A．T穩定的配對特質，任何一段核酸序列均可在一廣泛的核酸混合體中，找到與他相對應的核酸序列。此一特性已被廣泛用於各種重要的生物科技中，如PCR及Southern Blotting等。但目前研究顯現核酸雙螺旋結構並非必須完全以G．C及A．T配對；一些穩定的相鄰側記G．A配對（tandem sheared G．A base pairs）也可與G．C及A．T配對同時存在，並增加核酸雙螺旋結構的多樣性。估計如一般的核酸生物性與其多樣的特殊結構將逐步被解開，使吾人如愛麗思夢遊仙境般，步入一個奇妙的核酸世界。

關鍵字

核酸雙螺旋結構 ； 核磁共振 ； 相鄰側配G．A配對 ； 特殊配對

並列摘要

Watson-Crick GC and AT base paired duplex structure is probably the most important discovery of modem biology. It can well explain the genetic data of bean hybridization studies by Mandel. Besides, the GC and AT pairing is also extensively applied in many important biotechniques, such as PCR (polymerase chain reaction) or Southern blotting etc. which all incorporate the idea that a primer or probe can automatically find its complementary partner in a big randomized nucleic acid pool. However, recent studies indicate that Watson-Crick GC and AT pairing are not the only stable base pairs in the duplex structure; tandem sheared GA pair and its variants are also found to be stable and can co-exist with the Watson-Crick GC and AT pairs, which can greatly increase the diversity of duplex structure. By using the now popular SELEX (selected enrichment of ligands by exponential multiplication) method, one can easily screen out single-stranded nucleic acid molecules that can adopt special secondary and tertiary structures to interact strongly with any target. Such so-called aptamers will find wide applications in modem biotechniques. It is therefore expected that a myriad of unusual nucleic acid structure and function will be discovered, and the advancement of such works will lead us into the Alice Wonderland of nucleic acid kingdom.

並列關鍵字

DNA ； NMR ； structure ； sheared GA pairing ； non-cannonical pairing