Partial purification and characterization of an alkaline dipeptide naphthylamidase (Arg-Arg-NAase) of the rat skin

Zusammenfassung

Eine Peptidase, die N-terminale Dipeptide von Arginyl-Arginin-Naphthylamid, Leucyl-Alanin-Napthhylamid und auch von Alanyl-Alanyl-Alanyl-Alanin (aber nicht von Alanyl-Alanyl-Alanin) liberieren kann, wurde von Rattenhaut durch Chromatographie an DEAE-Cellulose, Gel-Filtration an Sephadex G-100 und DEAE-Sephadex purifiziert. Das Enzympräparat war frei von Peptidasen, die Aminosäurenaphthylamide hydrolysieren. Die enzymatische Hydrolyse von Arginyl-Arginin-Naphthylamid war optimal bei pH 8,0 und wurde in Gegenwart von Chlorid-Ionen und Sulfhydryl-Gruppen gesteigert. Der K _m -Wert für die Hydrolyse von Arginyl-Arginin-Naphthylamid war 1 · 10⁻⁴ M.

Summary

A peptidase capable of cleaving N-terminal dipeptides from arginyl-arginine naphthylamide (Arg-Arg-NA), leucyl-alanine naphthylamide as well as from alanyl-alanyl-alanyl-alanine (but not alanyl-alanyl-alanine) was partially purified from rat skin homogenate by employing chromatography on DEAE-cellulose, gel filtration on Sephadex G-100 and DEAE-Sephadex. The final preparation was free from peptidases hydrolysing monoamino acid naphthylamides. The enzyme was optimally active at pH 8.0. The enzymic hydrolysis of Arg-Arg-NA was enhanced by chloride ions and sulfhydryl compounds. K _m value was 1×10⁻⁴ M with Arg-Arg-NA as substrate.