Natural or unnatural single-stranded nucleic acids can bind to the complementary nucleic acid strand(s) with sequence specificity to form duplex or triplex structure. Such property could play a crucial rule for developing various bio-products through successful application of gene-related bio technologies.
Natural nucleic acids (DNA and RNA), however, are well known to have not so high binding ability and decompose rapidly by nucleases, concluding less usefulness as a molecular tool for biotechnologies. Numbers of artificial nucleic acids have been developed for excellent tool of the biotechnologies. In 1997, we created the fiurst generated BNA, 2’-O,4’-C-methylene-bridged nucleic acid(2’,4’-BNA) as a novel nucleic acid analog, a potential molecular tool for biotechnologies, on a basis of conformational features of natural nucleic acids. 2’,4’-BNA-oligos (oligonucleotides modified with one to several unit(s) of 2’,4’-BNA monomer) exhibit extremely high binding abilities against not only single-stranded RNA, DNA complements but also double-stranded DNAs, along with a moderate nuclease resistant property. Now a day, 2’,4’-BNA is widely used for various practical applications, such as for therapeutics, diagnostics, researching reagents, as the name “LNA.”
Following innovation of 2’,4’-BNA (LNA), we have been continuously producing new generations’ BNAs: 2’,4’-BNACOC , 3’-, and 5’-amino-2’,4’-BNAs (the second generation) gain higher nuclease resistant ability with remaining strong binding abilities, and 2’,4’-BNANC(the third generation) is shown to be most potential from the viewpoints of both binding and nuclease resistant abilities. Especially, have high binding selectivity to single-stranded RNA complement. These BNAs, possessing desired profiles for application to bio technologies, should be “key materials” to make various kinds of valuable gene-related bio-products.