Part:BBa_K4693002

Cortisol 85-mer aptamer

Main

The 85-mer cortisol aptamer is a single-stranded DNA molecule that is 84 nucleotides long. It has a molecular weight of 26,051.8 g/mole, an extinction coefficient of 802,200 L/(mole·cm), and a GC content of 54.76%. It binds to cortisol with high affinity and specificity, with a dissociation constant (Kd) of approximately 10 nM.

Aptamers are synthetic nucleic acid molecules that can bind to a wide variety of targets, including proteins, peptides, small molecules, and even cells. They are selected through a process called systematic evolution of ligands by exponential enrichment (SELEX), in which a large library of random nucleic acid sequences is screened for molecules that bind to the target of interest.

Source

Martin, J. A., Chávez, J. L., Chushak, Y., Chapleau, R. R., Hagen, J., & Kelley-Loughnane, N. (2014). Tunable stringency aptamer selection and gold nanoparticle assay for detection of cortisol. Anal. Bioanal. Chem. 2015 Mar 13; 406(19): 4637–4647. doi:10.1007/s00216-014-7883-8

Modifications

Towards the 5' end, we added a fluorescein based fluorophore FAM, which is excited around 490nm with an emission maxima of 520nm.