title: Effect of long time storage on cytosolic glutathione S-transferases.
abstract: Glutathione S-transferases are a family of enzymes catalyzing the conjugation of glutathione to a wide variety of compounds. Stability of human liver cytosolic glutathione S-transferase enzyme activity and levels of glutathione S-transferase class Alpha and Mu were assessed. Cytosolic fractions of sixteen different patients were stored up to two years at three different temperatures: -20 degrees, -80 degrees and -196 degrees Celsius. Samples were assayed for glutathione S-transferase enzyme activity and glutathione S-transferase class Alpha and Mu levels, after 3, 6, 12 and 24 months of storage. No significant differences in glutathione S-transferase enzyme activity as well as in isoenzyme levels were found during this 24 months of storage at the three different temperatures. It is concluded that stability of glutathione S-transferases allows long term storage even at -20 degrees C, without significant loss of enzyme activity or enzyme protein.
authors.affiliation: Dept. of Gastroenterology, University Hospital St Radboud, Nijmegen, The Netherlands.
authors.forename: W H
authors.initials: WH
authors.lastname: Peters
authors.forename: H M
authors.initials: HM
authors.lastname: Roelofs
mesh_terms: D003080:Cold Temperature; D015925:Cryopreservation; D004795:Enzyme Stability; D005982:Glutathione Transferase / Q000378:metabolism*; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism*; D008099:Liver / Q000201:enzymology*; D013997:Time Factors
chemical_list: D007527:Isoenzymes; D005982:Glutathione Transferase