Aptamer

“Aptamer” is a technical term in the bioscience field, referring to a molecule that binds with one or more target molecules. The molecular skeleton of an aptamer may be either a nucleic acid base sequence or an amino acid sequence, and the molecule is termed a “nucleic acid aptamer” or a “peptide aptamer”, respectively.

The molecules currently in widest use as molecular-targeted agents and molecular-recognition elements in the drug discovery and diagnostic agent fields are polyamino-acid proteins and antibodies.

However, even among aptamers, those nucleic acid aptamers that are polynucleotides (i.e. high-molecular-weight compounds with nucleic acid bases and sugars bound together) are biological high-molecular-weight compounds that offer the below advantages not shown by peptides, proteins or antibodies, and it is hoped that they will be new molecular-targeted agents and molecular-recognition elements.

Advantages of nucleic acid aptamers

(1) Available at low cost and in the short term
・A molecule of consistent quality can usually be provided, with almost no difference between lots.
・Synthesis can be ordered inexpensively simply by sending the sequence via the Internet. There are numerous synthesis contract companies, both in Japan and overseas, and there is intense competition to reduce prices.
・It is easy to design and construct original molecules such as aptamer linkers, etc., and molecules such as biospecific antibodies can thus readily be obtained.
・Comparison of in-house introduction of aptamer and antibody-capture assay systems shows that aptamer-capture assay systems are overwhelmingly superior in terms of cost of facilities and space taken up by the assay system.

(2) There is no deterioration due to degradation
・There is no need to control the temperature during shipment or storage.
・Long-term storage is possible.

(3) There are complementary chains
・In the case of use as molecular-targeted agents, pharmacological activities can be neutralized by a complementary chain.