title: Purification and characterization of three forms of glutathione transferase from Proteus mirabilis.
abstract: Three forms of glutathione transferase (GST) with pI values of 6.0, 6.4 and 7.3 were isolated from Proteus mirabilis AF 2924 by glutathione-affinity chromatography followed by isoelectric focusing, and their structural, kinetic and immunological properties were investigated. Upon SDS/polyacrylamide-slab-gel electrophoresis, all forms proved to be composed of two subunits of identical (22,500) Mr. GST-6.0 and GST-6.4 together account for about 95% of the total activity, whereas GST-7.3 is present only in trace amounts. Extensive similarities have been found between GST-6.0 and GST-6.4. These include subunit molecular mass, amino acid composition, substrate specificities and immunological characteristics. GST-7.3 also cross-reacted (non-identity) with antisera raised against bacterial GST-6.0. None of the antisera raised against a number of human, rat and mouse GSTs cross-reacted with the bacterial enzymes, indicating major structural differences between them and the mammalian GSTs. This conclusion is further supported by c.d. spectra.
authors.affiliation: Istituti di Scienze Biochimiche, Facoltà di Medicina, Università G. D'Annunzio, Roma, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Di Ilio
authors.forename: A
authors.initials: A
authors.lastname: Aceto
authors.forename: R
authors.initials: R
authors.lastname: Piccolomini
authors.forename: N
authors.initials: N
authors.lastname: Allocati
authors.forename: A
authors.initials: A
authors.lastname: Faraone
authors.forename: L
authors.initials: L
authors.lastname: Cellini
authors.forename: G
authors.initials: G
authors.lastname: Ravagnan
authors.forename: G
authors.initials: G
authors.lastname: Federici
mesh_terms: D000596:Amino Acids / Q000032:analysis; D002942:Circular Dichroism; D003600:Cytosol / Q000201:enzymology; D004591:Electrophoresis, Polyacrylamide Gel; D005982:Glutathione Transferase / Q000302:isolation & purification* / Q000378:metabolism; D005779:Immunodiffusion; D007525:Isoelectric Focusing; D007527:Isoenzymes / Q000302:isolation & purification* / Q000378:metabolism; D011513:Proteus mirabilis / Q000201:enzymology*; D013379:Substrate Specificity
chemical_list: D000596:Amino Acids; D007527:Isoenzymes; D005982:Glutathione Transferase