In this module you will investigate RNA aptamer selection. You may already be familiar with peptides or proteins, such as antibodies, that bind to specific molecules. Short fragments of RNA – called RNA aptamers - can have secondary structures that also allow them to bind a target molecule with good affinity and specificity. Normally, RNA aptamers that bind particular targets are found by screening many candidates at random in a process called SELEX, or systematic evolution of ligands by exponential enrichment; however, predictive computational tools can also be used. In the coming weeks, you will essentially perform one round of SELEX. Because SELEX typically takes several rounds to isolate target-binding aptamers, you will start with a known aptamer mixture rather than than a completely random library. Your goal will be to explore what experimental parameters affect the enrichment of a heme-binding RNA aptamer from a mixture of heme-binding and non-binding RNAs.
We thank 20.109 instructor Natalie Kuldell for helpful discussions and for acquiring funding for module development.