title: Individual recombinant thyroglobulin type-1 domains are substrates for lysosomal cysteine proteinases.
abstract: Thyroglobulin contains 11 repeats of a motif called thyroglobulin type-1 domain that show sequence similarity to some proteins exhibiting inhibitory activity against cysteine proteinases. Here we report that thyroglobulin decreases the activity of cathepsins B, H, L, and papain. To examine the possible involvement of particular type-1 domains in that decrease of activity, some individual thyroglobulin type-1 domains were expressed in E. coli. These recombinant domains proved to be substrates for cathepsins B, H, L, and papain instead of inhibitors. The cleavage points with cathepsins B and L on the second and the fourth domains were determined. The possible reasons for degradation are discussed.
authors.affiliation: Department of Biochemistry and Molecular Biology, Jozef Stefan Institute, Jamova 39, SI-1 000 Ljubljana, Slovenia.
authors.forename: Galina
authors.initials: G
authors.lastname: Pungercic
authors.forename: Iztok
authors.initials: I
authors.lastname: Dolenc
authors.forename: Marko
authors.initials: M
authors.lastname: Dolinar
authors.forename: Tadeja
authors.initials: T
authors.lastname: Bevec
authors.forename: Sasa
authors.initials: S
authors.lastname: Jenko
authors.forename: Sasa
authors.initials: S
authors.lastname: Kolaric
authors.forename: Vito
authors.initials: V
authors.lastname: Turk
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002403:Cathepsins / Q000378:metabolism; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D008247:Lysosomes / Q000201:enzymology*; D008969:Molecular Sequence Data; D017510:Protein Folding; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D013954:Thyroglobulin / Q000737:chemistry / Q000378:metabolism*
chemical_list: D011994:Recombinant Proteins; D013954:Thyroglobulin; D002403:Cathepsins; D003546:Cysteine Endopeptidases