Figure 6.

Aspartame- and caffeine-dependent RiboReporter™ sensors. (A) Aspartame- and caffeine-responsive sensors were configured for a fluorescence-based read-out. Upon binding of effector, the ribozyme undergoes self-cleavage and releases a short fluorescein-labeled product oligonucleotide which generates a fluorescent signal at 535 nm upon excitation at 488 nm. (B) Nucleotide sequences of aspartame sensors S3.asp.A2 and S3.asp.E4 and caffeine-dependent sensor S2.caf.D11 including the sequence appended to the 5′ end post-selection to enable hybridization of a quenching oligonucleotide.