title: Covalent association of protein disulfide isomerase with recombinant human interleukin 2 in vitro.
abstract: Protein disulfide isomerase has broad specificity in the catalysis of the formation and rearrangement of native disulfide bonds in proteins. This enzyme has two independent thioredoxin-like active sites (-CGHC-) and a peptide binding site. However, the mechanisms involving the catalytic processes are not clearly understood. It was reported that the enzyme associates with scrambled pancreatic ribonuclease A in vitro, and with misfolded human lysozyme in vivo. In the present study, recombinant human interleukin 2 has been chosen to probe the reaction intermediate in the reaction with the enzyme. We have identified and characterized a covalent associate formed in vitro by SDS-PAGE and Western blot analysis. This associate has a molecular weight of 71-72 kDa, the approximate sum of the molecular weights of the enzyme and the substrate. Western blot analysis confirmed that it formed via an intermolecular disulfide bond. Upon treatment with 2-mercaptoethanol, this bond was cleaved.
authors.affiliation: Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee, Memphis 38163, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Ye
authors.forename: C J
authors.initials: CJ
authors.lastname: Key
authors.forename: J L
authors.initials: JL
authors.lastname: Wolfe
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D001665:Binding Sites; D015153:Blotting, Western; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007376:Interleukin-2 / Q000302:isolation & purification / Q000378:metabolism*; D007535:Isomerases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D011485:Protein Binding; D019704:Protein Disulfide-Isomerases; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D007376:Interleukin-2; D011994:Recombinant Proteins; D007535:Isomerases; D019704:Protein Disulfide-Isomerases