Propeptide of the metalloprotease of Brevibacillus brevis 7882 is a stronginhibitor of the mature enzyme

A metalloprotease gene of Brevibacillus brevis (npr) was expressed in Esche richia coli in a soluble form as native Npr precursor. A significant fracti on of the precursor was spontaneously processed, producing the N-terminal p ropeptide and the mature enzyme, A strong inhibition of the mature Npr by i ts own propeptide in the crude lysate was observed even in the absence of t he covalent linkage between them. Pure precursor, propeptide and the mature Npr were isolated and kinetic parameters of the mature enzyme inhibition b y the propeptide were determined, The inhibition is of the tight-binding co mpetitive type with Ki 0.17 nM, Inhibition of metalloproteases from Breviba cillus megaterium and thermolysine by the heterologous propeptide of the Np r from B, brevis was much weaker or none, (C) 1999 Federation of European B iochemical Societies.