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 (<30kDa, 30-100kDa and >100kDa). No glycation sites were found by computer analysis of the hIDS sequence; discarding the possibility of marks for glycation and proteolytic processing.