TY - JOUR
T1 - Glutathione s-transferases of bovine iris and ciliary body
T2 - Characterization of isoenzymes
AU - Ahmad, Hassan
AU - Singh, Shivendra V.
AU - Srivastava, Satish K.
AU - Awasthi, Yogesh C.
N1 - Funding Information:
ACKNOWLEDGEMENTS This investigation was supported in part by US PHS grants EY 04396 awarded by The National Eye Institute; CA 27967 awarded by The National Cancer Institute and GM 32304 awarded by The National Institute for General Medical Sciences.
PY - 1989
Y1 - 1989
N2 - Five forms of glutathione (GSH) S-transferase (GST) having catalytic activities towards a variety of xenobiotics were present in bovine iris-ciliary body. In contrast to that in lens, cornea, and retina, GST isoenzymes belonging to all the three classes (αmu; and π were present in iris as well as in the ciliary body. GST isoenzymes of iris-ciliary body had pI values of 8.7, 7.4, 7.0, 6.6, and 6.0. GST 8.7 and GST 7.4 were apparent homodimers of 27,000 and 22,500 Mr. subunits, respectively. GST 8.7 cross-reacted only with antibodies raised against the a class GST of human liver and GST 7.4 cross-reacted with the antibodies raised against GST π of human placenta. GST 7.0 and 6.6 were heterodimers of MR 26,500 and 25,000 subunits and both these subunits cross-reacted with the antibodies raised against the μ class human GST. Iris-ciliary body contained both, GSH peroxidase I and GSH peroxidase II activities and in this respect also, they differ from lens, cornea, and retina each of which have only one of these two activities. The presence of several GST isoenzymes belonging to all the three major classes and both GSH peroxidase I and II activities in iris-ciliary body may be important for the detoxification of oxidants and xenobiotics in order to prevent their infiltration in aqueous humor.
AB - Five forms of glutathione (GSH) S-transferase (GST) having catalytic activities towards a variety of xenobiotics were present in bovine iris-ciliary body. In contrast to that in lens, cornea, and retina, GST isoenzymes belonging to all the three classes (αmu; and π were present in iris as well as in the ciliary body. GST isoenzymes of iris-ciliary body had pI values of 8.7, 7.4, 7.0, 6.6, and 6.0. GST 8.7 and GST 7.4 were apparent homodimers of 27,000 and 22,500 Mr. subunits, respectively. GST 8.7 cross-reacted only with antibodies raised against the a class GST of human liver and GST 7.4 cross-reacted with the antibodies raised against GST π of human placenta. GST 7.0 and 6.6 were heterodimers of MR 26,500 and 25,000 subunits and both these subunits cross-reacted with the antibodies raised against the μ class human GST. Iris-ciliary body contained both, GSH peroxidase I and GSH peroxidase II activities and in this respect also, they differ from lens, cornea, and retina each of which have only one of these two activities. The presence of several GST isoenzymes belonging to all the three major classes and both GSH peroxidase I and II activities in iris-ciliary body may be important for the detoxification of oxidants and xenobiotics in order to prevent their infiltration in aqueous humor.
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U2 - 10.3109/02713688908995189
DO - 10.3109/02713688908995189
M3 - Article
C2 - 2714102
AN - SCOPUS:0024477407
SN - 0271-3683
VL - 8
SP - 175
EP - 184
JO - Current Eye Research
JF - Current Eye Research
IS - 2
ER -