The recombinant human iduronate 2-sulfate sulfatase (hrIDS) was transiently and functionally active expressed in E. coli K12. The enzyme activity (crude extract) at 100 ml and 400 ml oscillated between 0.25 and 10.58 nmol h-1 mg-1. The wide Western-blot peptide profile suggest that hrIDS is proteolitically processed "randomly" which agrees with the ultrafiltration assay in which the hrIDS activity was found in all fractions (100kDa). No glycation sites were found by computer analysis of the hIDS sequence; discarding the possibility of marks for glycation and proteolytic processing.