Characterization of porcine Alpha-class glutathione transferase A1-1
2011 (English)In: Archives of Biochemistry and Biophysics, ISSN 0003-9861, E-ISSN 1096-0384, Vol. 507, no 2, 205-211 p.Article in journal (Refereed) Published
An Alpha-class glutathione transferase (GST) has been cloned from pig gonads. In addition to two conservative point mutations our nucleotide sequence presents a frame shift resulting from a missing A as compared to a previously published porcine GST A1-1 sequence. The deduced C-terminal amino-acid segment of the protein differs between the two variants. Repeated sequencing of cDNA isolated from different tissues and animals ruled out the possibility of a cloning artifact, and the deduced amino acid sequence of our clone showed higher similarity to related mammalian GST sequences. Hereafter, we refer to our cloned enzyme as GST A1-1 and to the previously published enzyme as GST A1-1(∗). The study of the tissue distribution of the GSTA1 mRNA revealed high expression levels in many organs, in particular adipose tissue, liver, and pituitary gland. Porcine GST A1-1 was expressed in Escherichia coli and its kinetic properties were determined using alternative substrates. The catalytic activity in steroid isomerization reactions was at least 10-fold lower than the corresponding values for porcine GST A2-2, whereas the activity with 1-chloro-2,4-dinitrobenzene was approximately 8-fold higher. Differences in the H-site residues of mammalian Alpha-class GSTs may explain the catalytic divergence.
Place, publisher, year, edition, pages
2011. Vol. 507, no 2, 205-211 p.
Sus scrofa, Glutathione transferase A1-1, Alternative sequence, Substrate selectivity
Research subject Neurochemistry and Molecular Neurobiology
IdentifiersURN: urn:nbn:se:su:diva-53692DOI: 10.1016/j.abb.2010.12.015ISI: 000288058000001PubMedID: 21172301OAI: oai:DiVA.org:su-53692DiVA: diva2:391146