Characterization of a secreted form of human furin endoprotease

Biochem Biophys Res Commun. 1993 Sep 15;195(2):1011-8. doi: 10.1006/bbrc.1993.2145.


Human furin, a member of a recently discovered family of cellular endoproteases, has been identified as a membrane bound protein localized in the Golgi apparatus. Here, we report the presence of a secreted form of furin in the media of cells infected with a vaccinia virus recombinant containing the furin gene. Using the fluorogenic substrate boc-Arg-Val-Arg-Arg-MCA, endoproteolytic activity was detected in the media of infected BSC40 cells. Immunoprecipitations of [35S]-labeled proteins from infected cells revealed that the media contained a lower molecular form of furin than the cellular furin or than a previously characterized soluble furin mutant, hFUR713t. By using the direct linear plot representation of the Michaelis-Menten equation the results demonstrate that the soluble furin exhibited similar kinetics to the hFUR713t enzyme. Thus, our results suggest that membrane-bound furin undergoes post-translational processing to produce a soluble form of the enzyme that can be secreted.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cell Line
  • Chlorocebus aethiops
  • Furin
  • Humans
  • Kidney
  • Kinetics
  • Molecular Sequence Data
  • Proteins / isolation & purification
  • Proteins / metabolism
  • Recombinant Proteins / biosynthesis
  • Recombinant Proteins / metabolism
  • Substrate Specificity
  • Subtilisins / biosynthesis
  • Subtilisins / genetics
  • Subtilisins / metabolism*
  • Transfection
  • Vaccinia virus / genetics


  • Proteins
  • Recombinant Proteins
  • Subtilisins
  • Furin