A team led by Scripps Research Institute's Gerald Joyce received a $324,000 grant this month from the National Institutes of Health, extending previous funding for a project to develop a method analogous to quantitative PCR, but based on autocatalytic RNA enzymes, for protein and small molecule detection.
Joyce's autocatalytic aptazyme project has been developing these enzymes — which undergo self-sustained exponential replication initiated and constrained by the concentration of a particular ligand or target molecule in a sample — for multiplex, quantitative detection of protein or other small-molecule targets in biological or environmental samples.
As in quantitative PCR, the autocatalytic aptazyme system will enable quantitation of target molecules by harnessing exponential growth.
In qPCR, Joyce explained to PCR Insider last year, the number of PCR cycles before a reaction hits a set threshold gives a readout of the concentration of the target nucleic acid. The same is true of the self-replicating apatzymes Joyce's team has been developing.
The autocatalytic apatzymes are built out of non-biological, L-RNA molecules with the same self-replicating properties of their biological enantiomeric twins but with the bonus of being completely resistant to breakdown by ribonucleases.
According to the abstract of the team's recent grant extension, this newest round of funding will support continuing work to generalize the system so that it can be applied to a broad range of targets, including disease-related proteins, drugs, and metabolites.
The group eventually plans to develop a real-time fluorescent assay for high-throughput, multiplex analysis based on the technology.
According to the abstract, the researchers are also planning to investigate the ability of the replicating enzymes to evolve in a self-sustained manner, configuring themselves to recognize a target molecule on their own, in something like a synthetic, test-tube version of the maturation of antigen recognition by the immune system.