Modified peptide substrate

摘要

The invention provides novel reagents and methodologies for detecting free versus bound enzyme. It is particularly useful to detect thrombin when it is not bound to A2M in the presence of thrombin bound to A2M by using a modified substrate that is sterically hindered from reacting with the bound thrombin.

主权项

1. A modified thrombin-reactive peptide substrate, comprising a thrombin-reactive peptide substrate which is modified by the attachment thereto of a macromolecule via a spacer that comprises 9-15 atoms such that the modified thrombin-reactive peptide substrate is cleavable by a free thrombin but not by thrombin bound in a molecular trap, wherein the thrombin-reactive peptide substrate is a tripeptide consisting of the sequence -Xaa1-Xaa2-Arg-, Xaa1 being an aliphatic amino acid or an aromatic amino acid and Xaa2 being an amino acid comprising an aliphatic chain, a pyrrolidine ring, or a piperidine ring.