title: In vitro biosynthesis of the lysosomal cathepsin H.
abstract: A lysosomal thiol protease cathepsin H has been synthesized in vitro and shown to undergo co-translational segregation into the lumen of microsomal vesicles. Using cell-free synthesis, a 36 K Da cathepsin H was found to be synthesized exclusively on membrane-bound polysomes. When the microsomal membrane were present during translation, a glycosylated 41 K Da proenzyme appeared in the microsomal lumen. This proenzyme was converted to a 34 K Da protein by endoglycosidase H treatment. These results suggest that the nascent chain of cathepsin H has a transient N-terminal prepropeptide.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D056655:Cathepsin H; D002403:Cathepsins / Q000096:biosynthesis*; D002474:Cell-Free System; D003546:Cysteine Endopeptidases; D004285:Dogs; D008247:Lysosomes / Q000201:enzymology*; D008970:Molecular Weight; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats
chemical_list: D012333:RNA, Messenger; D002403:Cathepsins; D003546:Cysteine Endopeptidases; D056655:Cathepsin H; C534128:Ctsh protein, rat