Determination of antigenic epitopes recognized by four monoclonal antibodies to glutathione S-transferase pi (GST-pi).
Four independent antibodies (6A, 5F, 2H and 2F) to Glutathione S-transferase pi (GST-pi) were selected to characterize their epitopes. Amino acid analysis of 5.6 K and 7.4 K tryptic peptides appeared to suggest that the epitope recognized by antibodies 2H and 2F is located in the N-terminal 44 peptides of GST-pi, and that of 6A and 5F is located in the C-terminal 69 peptides. Reactivities of antibodies 6A and 5F with two synthetic peptides indicated that 6A recognized an epitope in the C-terminal hydrophilic fragment 176Leu-209Gln, and could be distinguished from 5F which recognized an epitope in the 141Thr-176Leu hydrophobic fragment. The differential immuno-reactivity of antibodies 6A and 5F with GST-pi itself, was characterized by the particularly high reactivity of 6A and almost no reactivity of 5F with the natural conformation of GST-pi in solution. This may be explained by differences in the hydropathic natures of their epitopes. The 6A antibody was useful for immunodetection of GST-pi in circulation, while 5F was found to be most suitable for histochemical staining of tumor tissue.
Teijin Institute for Biomedical Research, Tokyo, Japan.
K
K
Hosoda
M
M
Okada
Y
Y
Hirata
T
T
Saito
N
N
Arisato
S
S
Ishigaki
Y
Y
Niitsu
D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal / Q000302:isolation & purification; D000918:Antibody Specificity; D001710:Biotin; D015153:Blotting, Western; D003488:Cyanogen Bromide; D000939:Epitopes / Q000032:analysis*; D005982:Glutathione Transferase / Q000276:immunology*; D006801:Humans; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000276:immunology; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis / Q000276:immunology; D014357:Trypsin
D000911:Antibodies, Monoclonal; D000939:Epitopes; D007527:Isoenzymes; D010455:Peptides; D001710:Biotin; D005982:Glutathione Transferase; D014357:Trypsin; D003488:Cyanogen Bromide