Abstract: The disclosure relates to the use of a proteolytic enzyme substrate of general formula: Q1-Xaa2-Xaa1-rhodamine110-Q2, in which: Xaa1 and Xaa2 are amino acids and Q2 is a group comprising an alkyl group; so as to be able to allow, in a blood sample containing a glycosaminoglycan, said glycosaminoglycan to inhibit the coagulation of said blood sample, via which the anticoagulant capacity of the glycosaminoglycan is not disrupted.

Abstract: The disclosure relates to the use of a proteolytic enzyme substrate of general formula: Q1-Xaa2-Xaa1-rhodamine110-Q2, in which Xaa1 and Xaa2 are amino acids and Q2 is Xaa1-Xaa2-Q1, or an amino acid Xaa3, or a group comprising an aryl group, or H, so as to be able to inhibit, in a blood sample containing a glycosaminoglycan, the anticoagulant capacity of said glycosaminoglycan. The invention also relates to a method for measuring an enzymatic activity using such a substrate and a kit for implementation thereof.