PURIFICATION AND CHARACTERIZATION OF GLUTATHIONE-S-TRANSFERASE FROM HUMAN TONSILS

An acidic (pI 4.6) isoform of glutathione S-transferase (GST) was purified from human palatine tonsils by affinity column chromatography. Molecular weight of the subunit was estimated to be 22,000 by sodium dodecylsulfate polyacrylamide gel electrophoresis. Sequence analysis of purified GST gave only a single sequence, identical to GST-pi. By the double immunodiffusion technique, anti-GST-pi antibody formed precipitin lines not only with tonsillar GST but also with a lysate of peripheral lymphocytes. However, the specific activity of GST in tonsillar cytosol was higher than in the lymphocyte lysate. Furthermore, immunohistochemical study with anti-GST-pi antibody showed that most epithelial cells were stained intensively, whereas only a small number of lymphocytes were stained. The present data suggest that the epithelial cells contain GST-pi at a higher concentration than lymphocytes.