title: Combination of the human prolyl isomerase FKBP12 with unrelated chaperone domains leads to chimeric folding enzymes with high activity.
abstract: Folding enzymes often use distinct domains for the binding of substrate proteins ("chaperone domains") and for the catalysis of slow folding reactions such as disulfide formation or prolyl isomerization. The human prolyl isomerase FKBP12 is a small single-domain protein without a chaperone domain. Its very low folding activity could previously be increased by inserting the chaperone domain from the homolog SlyD (sensitive-to-lysis protein D) of Escherichia coli. We now inserted three unrelated chaperone domains into human FKBP12: the apical domain of the chaperonin GroEL from E. coli, the chaperone domain of protein disulfide isomerase from yeast, or the chaperone domain of SurA from the periplasm of E. coli. All three conveyed FKBP12 with a high affinity for unfolded proteins and increased its folding activity. Substrate binding and release of the chimeric folding enzymes were found to be very fast. This allows rapid substrate transfer from the chaperone domain to the catalytic domain and ensures efficient rebinding of protein chains that were unable to complete folding. The advantage of having separate sites, first for generic protein binding and then for specific catalysis, explains why our construction of the artificial folding enzymes with foreign chaperone domains was successful.
authors.affiliation: Laboratorium für Biochemie und Bayreuther Zentrum für Molekulare Biowissenschaften, Universität Bayreuth, D-95440 Bayreuth, Germany.
authors.forename: Anne-Juliane
authors.initials: AJ
authors.lastname: Geitner
authors.forename: Franz Xaver
authors.initials: FX
authors.lastname: Schmid
mesh_terms: D001665:Binding Sites; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002384:Catalysis; D020134:Catalytic Domain; D004926:Escherichia coli / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D008958:Models, Molecular; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism*; D019696:Peptidylprolyl Isomerase / Q000235:genetics / Q000378:metabolism*; D011392:Proline / Q000378:metabolism; D011485:Protein Binding; D019704:Protein Disulfide-Isomerases / Q000235:genetics / Q000378:metabolism*; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D013379:Substrate Specificity; D022061:Tacrolimus Binding Protein 1A / Q000235:genetics / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; D029968:Escherichia coli Proteins; C028715:GroE protein, E coli; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; D011993:Recombinant Fusion Proteins; C085606:SlyD protein, E coli; D011392:Proline; C490900:SurA protein, E coli; D022061:Tacrolimus Binding Protein 1A; D019696:Peptidylprolyl Isomerase; D019704:Protein Disulfide-Isomerases