Locked nucleic acid (LNA) is a modified RNA nucleoside analog consisting of one or more LNA nucleotide monomers in which the bicyclic furanose unit is locked in an RNA mimetic sugar conformation. LNA oligonucleotides have good recognition and strong affinity for DNA and RNA. Structural studies have shown that LNA oligonucleotides induce A-type (RNA-like) double-stranded conformations. Mechanistically, the 2'-O and 4'-C atoms on the ribose of LNA form a methylene bridge through different condensation interactions and are connected into a ring, thus "locking" the ribose ring in the desired Watson-Crick binding conformation. When incorporated into DNA or RNA Oligos, LNA can pair with complementary nucleotide strands faster and improve the stability of the resulting duplex. LNA has high thermal stability and is an ideal modification method for gene function (mRNA, non-coding RNA), inhibitory reagents ASO, inhibitor, antagomir and other RNA. Moreover, it can also be used in various probes and PCR primers, and suitable for detecting highly similar but short-length sequences, DNA, or long RNA sequences (such as mRNA). LNA-modified antisense nucleotides have become a new generation of antisense nucleic acid drugs.
Fig.1 Chemical structure of an LNA monomer: additional bridge bond between the 2' oxygen and the 4' carbon of the pentose
BOC Sciences can provide oligonucleotide synthesis services according to customers' design sequence or LNA modification requirements, such as modification sites, quantity, phosphorylation requirements, etc.
- Conventional nucleotides or phosphorylated nucleotides can be modified.
- Flexible modification: LNA can be introduced to any sequence position.
- Upregulated thermal stability: Tm of the duplex increases by 2-8°C with every incorporated LNA.
- High sensitivity and specificity: changing the content of LNA can significantly improve the sensitivity and specificity of PCR/microarray/FISH and distinguish single-base mismatches.
- Regardless of the GC content, LNA can accurately detect DNA or RNA sequences of short length and high similarity, as well as in vivo experiments.
- Suitable for various complex samples, such as body fluids and FFPE samples.
Characteristics of LNA
- Upregulates primer or probe's Tm values to improve affinity and action specificity.
- Activates RNase H response, suitable for gene suppression experiments.
- Can be identified by general biological enzymes, such as T4 ligase, DNA polymerase.
- Resists to exoenzyme or endoenzyme decomposition.
- Enhances the stability of general gene suppression probes and siRNA (in vitro and in vivo) and prolongs action duration.
- Labels commonly use fluorescent or semi-antigenic molecules, such as DIG, Fluorescein, Biotin.
- Low cytotoxicity and good hydrophilicity.
- Antisense nucleic acid drug modification
- RNA function inhibition research (ASO, inhibitor, antagomir, etc.)
- SNP detection
- In situ hybridization (FISH probe)
- Microarray analysis
- Other RNA modifications (Decoy, Aptamer, etc.)
- Quantitative Real-time PCR
- Other DNA modification sequences
- Vester R.; et al. LNA (locked nucleic acid): high-affinity targeting of complementary RNA and DNA. Biochemistry. 2004 Oct 26; 43(42): 13233-41.
- Petersen M; et al. LNA: a versatile tool for therapeutics and genomics. Trends Biotechnol. 2003 Feb; 21(2): 74-81.