A Red Cy3-Based Biarsenical Fluorescent Probe Targeted to a Complementary Binding Peptide

摘要

We have synthesized a new biarsenical fluorescent probe, AsCy3, that in conjunction with a high-affinity binding motif (i.e., Cy3TAG) (CCKAEAACC) permits specific labeling of the Cy3TAG in the presence of the previously identified FlAsHTAG (CCXXCC). Further, AsCy3 provides a FRET partner to the biarsenical dye FlAsH, permitting measurements of protein-protein interactions. AsCy3 has superior photostability and a minimal environmental sensitivity compared to the existing biarsenical probes FlAsH and ReAsH. Thus, the discovery of the new biarsenical probe AsCy3 provides an important next step in developing a whole toolkit of colored probes directed to different small binding motifs.