High molecular weight derivative of trypsin‐kallikrein inhibitor for potential medical use, 1. Preparation and characterization

Abstract

Abstract Bovine trypsin‐kallikrein inhibitor (TKI) was bound on three different water‐soluble hydrophilic carriers derived from poly[ N ‐(2‐hydroxyethyl)‐D,L‐aspartamide] and containing a binding group (aromatic amine) and an additional modifying group (anionic or hydrophobic). The binding was performed by coupling of diazonium salts formed on the carrier with tyrosines in TKI. The product was characterized by means of sedimentation measurement, viscometry, electrophoresis, amino acid analysis, GPC, and antiproteolytic activity. TKI was found to be attached to the carrier by one or two tyrosines, the latter case being more frequent than it would correspond to independent random reactivity of the accessible tyrosines and the carrier molecules are crosslinked by the attached TKI. This is due to a fraction of two point attached TKI, as estimated according to a tree‐like model. All three samples preserved good activity toward trypsin and chymotrypsin.