title: A 4-methoxy-2-naphthylamide substrate for the histochemical localization of esteroproteases in the submandibular gland of the rat.
abstract: The 4-methoxynaphthylamide (MNA) derivative of D-Val-Leu-Arg-4-MNA has been used as a substrate for the histochemical localization of esteroproteases in the submandibular gland of rats, and compared with the substrate alpha N-O-met. The hydrolysis of Val-Leu-Arg-4-MNA by esteroproteases was investigated using spectrophotometry and isoelectric focusing. Both methods demonstrated that the substrate is cleaved by different enzymes and is not a monospecific kallikrein marker, although Val-Leu-Arg-4-MNA had a much smaller spectrum of enzyme activities than alpha N-O-met. The activity against Val-Leu-Arg-4-MNA was totally inhibited by aprotinin but only partly by soybean trypsin inhibitor. A comparison of the histochemical localization of esteroproteases given by the substrate with the immunofluorescence localization of kallikrein showed that all the enzymes that hydrolysed Val-Leu-Arg-4-MNA and kallikrein were present in the same tissue structures.
mesh_terms: D000818:Animals; D005455:Fluorescent Antibody Technique; D006651:Histocytochemistry; D007525:Isoelectric Focusing; D007610:Kallikreins / Q000032:analysis; D008297:Male; D009842:Oligopeptides; D010447:Peptide Hydrolases / Q000032:analysis* / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013363:Submandibular Gland / Q000201:enzymology*
chemical_list: D009842:Oligopeptides; C038043:valyl-leucyl-arginine-4-methoxy-2-naphthylamide; D010447:Peptide Hydrolases; D007610:Kallikreins