the present invention relates to pro - hormone convertases and polypeptidic fragments thereof , nucleic acids encoding them , recombinant viruses expressing these convertases , polyclonal antibodies directed against the convertases , diagnostic kits for the detection and measurement of the convertase content in cell or tissue lysates , culture media or biological fluids by ria . diagnostic kits were also developped for detection or measurement of nucleic acids , preferably mrnas , in cell or tissue lysates by hybridization . the invention also concerns oligonucleotides useful as probes or as primers for dna synthesis . these oligonucleotides were included in the diagnostic kits as well as used for the obtention of specific fragments of the convertases which have served , together with native convertases , as antigens for the obtention of antibodies . the convertases were produced by mammalian cell lines transfected with the recombinant viruses and purified on affinity columns which are also an object of the invention . processes for producing the native convertases , fragments thereof and antibodies are also described and claimed .