[New dipeptide fluorogenic substrates of human tissue kallikrein]

Area of Science:

• Biochemistry
• Enzymology
• Medicinal Chemistry

Context:

• Kallikreins are serine proteases involved in various physiological processes.
• Developing specific substrates is crucial for studying kallikrein activity and function.
• Existing substrates have limitations in sensitivity and specificity.

Purpose:

• To synthesize novel N-alkyloxycarbonyl derivatives of phenylalanine and leucine.
• To evaluate the enzymatic hydrolysis of these derivatives by human tissue and plasma kallikreins.
• To identify compounds with improved substrate properties for kallikrein detection.

Summary:

• Eleven Amc-derivatives (ROCO-Phe-Arg-Amc) and two additional derivatives (n-C3H7OCO-Leu-Arg-Amc, n-C3H7OCO-D-Phe-Arg-Amc) were synthesized.
• Human tissue kallikrein hydrolyzed n-propyl and n-butyl ROCO-Phe-Arg-Amc and n-C3H7OCO-Leu-Arg-Amc more efficiently than standard substrates.
• Human plasma kallikrein showed lower hydrolysis rates for these novel substrates compared to Z-Phe-Arg-Amc.

Impact:

• Identified novel substrates for human tissue kallikrein with potentially higher sensitivity.
• The D-Phe derivative acts as a weak inhibitor of tissue kallikrein.
• Findings contribute to the development of more specific kallikrein assays for research and diagnostics.