Figure 1.

Real-Time Proteolytic-Activity Biosensors and Personalized Medicine.

(A) Triangulation of proteolytic-activity sensors in real time onto personalized medicine. (B) Generalized scheme illustrating the working principle of a ‘molecular ruler’. Here, the interaction between two or more entities is distance dependent; thus, the signal detected by the sensor is strictly dependent on the distance. In proteolytic sensors, molecular-rulers operate to differentiate the signal of the intact molecule (absence of target protease) and that of a cleaved molecule (presence of target protease) in which the interaction between the entities cannot occur. (C) Schematic of proteolytic sensor based on the fragmentation of an original target molecule. In such systems, the cleavage of the original molecule induces a change of a given property, which will provide a sensor reading that is proportional to the proteolytic activity.