title: Protein disulphide isomerase-induced refolding of sonochemically prepared Ribonuclease A microspheres.
abstract: The present communication describes for the first time the development of Ribonuclease A (RNase A) microspheres using the sonochemical method followed by an enzymatic treatment with protein disulphide isomerase (PDI). Ultrasound application induced changes on the protein physicochemical and biological properties: the enzymatic activity of RNase A was decreased in 35% and the free thiol groups content was significantly increased, probably due to the breakage of protein disulphide bonds and assembly of RNase A monomers. The deconvolution of amide I band, from Fourier Transform Infrared Spectroscopy, showed that the secondary structure of RNase A was slightly changed after microspherization. The PDI application on microspheres promoted the recovery of RNase A biological activity and induced the release of active protein into solution in its native state. These results were promoted by different states of PDI active site: oxidized and reduced, respectively. The PDI aptitude to catalyze the refolding of a protein substrate in the form of spheres is here reported.
authors.affiliation: Textile Engineering Department, University of Minho, Campus of Azurém, Guimarães, Portugal.
authors.forename: Margarida M
authors.initials: MM
authors.lastname: Fernandes
authors.forename: Raquel
authors.initials: R
authors.lastname: Silva
authors.forename: Helena
authors.initials: H
authors.lastname: Ferreira
authors.forename: Ilaria
authors.initials: I
authors.lastname: Donelli
authors.forename: Giuliano
authors.initials: G
authors.lastname: Freddi
authors.forename: Artur
authors.initials: A
authors.lastname: Cavaco-Paulo
mesh_terms: D000818:Animals; D001709:Biotechnology / Q000379:methods*; D002417:Cattle; D008863:Microspheres; D010084:Oxidation-Reduction; D010316:Particle Size; D019704:Protein Disulfide-Isomerases / Q000378:metabolism*; D058849:Protein Refolding; D012259:Ribonuclease, Pancreatic / Q000737:chemistry* / Q000378:metabolism*; D013010:Sonication
chemical_list: D012259:Ribonuclease, Pancreatic; D019704:Protein Disulfide-Isomerases