title: Creation of a zymogen.
abstract: Cells produce proteases as inactive zymogens. Here, we demonstrate that this tactic can extend beyond proteases. By linking the N and C termini of ribonuclease A, we obstruct the active site with the amino acid sequence recognized by plasmepsin II, a highly specific protease from Plasmodium falciparum. We generate new N and C termini by circular permutation. In the presence of plasmepsin II, a ribonuclease zymogen gains approximately 10(3)-fold in catalytic activity and maintains high conformational stability. We conclude that zymogen creation provides a new and versatile strategy for the control of enzymatic activity, as well as the potential development of chemotherapeutic agents.
authors.affiliation: Department of Biochemistry, University of Wisconsin, Madison 53706-1544, USA.
authors.forename: Parit
authors.initials: P
authors.lastname: Plainkum
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Fuchs
authors.forename: Suthep
authors.initials: S
authors.lastname: Wiyakrutta
authors.forename: Ronald T
authors.initials: RT
authors.lastname: Raines
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D016282:Aspartic Acid Endopeptidases / Q000378:metabolism; D020134:Catalytic Domain / Q000235:genetics; D002417:Cattle; D004789:Enzyme Activation; D004792:Enzyme Precursors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D004795:Enzyme Stability; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics; D011487:Protein Conformation; D015800:Protozoan Proteins; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012259:Ribonuclease, Pancreatic / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D004792:Enzyme Precursors; D015800:Protozoan Proteins; D011994:Recombinant Proteins; D012259:Ribonuclease, Pancreatic; D016282:Aspartic Acid Endopeptidases; C100637:plasmepsin II