Figure 1.
Selective cathepsin K-mediated fluorescence probe activation in vitro. CatK fluorescence increases 5–6 fold following addition of cathepsin K enzyme, and is inhibited with the addition of the cathepsin K inhibitor. Isomeric control probe (d-control) remains unaffected by addition of protease. Trypsin fails to cleave CatK or d-control probes after 22 hours exposure, but successfully cleaves PS680, which contains L-lys-lys bonds in its backbone chain. These findings demonstrate selectivity of reporter probe linker sequence to cathepsin K cleavage and resistance of d-poly-lysine backbone to degradation. Data represent mean ± s.d. of three independent trials; * p<0.05 vs. CatK680.
