Pluripotentialities of a quenched fluorescent peptide substrate library: enzymatic detection, characterization, and isoenzymes differentiation.

Protease inhibitors represent a major class of drugs, even though a large number of proteases remain unexplored. Consequently, a great interest lies in the identification of highly sensitive substrates useful for both the characterization and the validation of these enzyme targets and for the design of inhibitors as potential therapeutic agents through high-throughput screening (HTS). With this aim, a synthetic substrate library, in which the highly fluorescent (L)-pyrenylalanine residue (Pya) is efficiently quenched by its proximity with the p-nitro-(L)-phenylalanine (Nop) moiety, was designed.

Identification of an endothelin-converting enzyme-2-specific fluorigenic substrate and development of an in vitro and ex vivo enzymatic assay.

Endothelin-converting enzyme-2 (ECE-2) is a membrane-bound zinc-dependent metalloprotease that shares a high degree of sequence homology with ECE-1, but displays an acidic pH optimum characteristic of maturing enzymes acting late in the secretory pathway. Although ECE-2, like ECE-1, can cleave the big endothelin intermediate to produce the vasoconstrictive endothelin peptide, its true physiological function remains to be elucidated, a task that is hampered by the lack of specific tools to study and discriminate ECE-2 from ECE-1, i.e.

Detection and quantification of botulinum neurotoxin type a by a novel rapid in vitro fluorimetric assay.

Botulinum neurotoxin type A (BoNT/A), the most poisonous substance known to humans, is a potential bioterrorism agent. The light-chain protein induces a flaccid paralysis through cleavage of the 25-kDa synaptosome-associated protein (SNAP-25), involved in acetylcholine release at the neuromuscular junction. BoNT/A is widely used as a therapeutic agent and to reduce wrinkles.