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Sulphydryl groups and their relation to the antioxidant enzymes of chelonian red blood cells
Author(s) -
Torsoni M. A.,
Viana R. I.,
Ogo S. H.
Publication year - 1998
Publication title -
iubmb life
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.132
H-Index - 113
eISSN - 1521-6551
pISSN - 1521-6543
DOI - 10.1080/15216549800203652
Subject(s) - hemoglobin , glutathione , glutathione reductase , glutathione peroxidase , antioxidant , catalase , superoxide dismutase , biochemistry , peroxidase , thiol , red blood cell , enzyme , gpx3 , biology , chemistry
Thiol groups of hemoglobin and blood glutathione are higher in Geochelone carbonaria than in Geochelone denticulata. Exposure of stripped hemolysate of both tortoises to terc‐butyl hydroperoxide, resulted in a higher ferroheme oxidation of G. denticulata hemoglobin. In this example glutathione reductase and glutathione peroxidase, were not active due to the absence of GSH and NADPH, suggesting that the thiol groups of G. carbonaria hemoglobin act as antioxidant, similar to GSH. In the total hemolysate, however, where the antioxidant enzymes are active, both species showed similar levels of hemoglobin oxidation, suggesting that the protective effect of thiol groups of hemoglobin are less effective for heme protection. The activity of glutathione reductase and glutathione peroxidase was higher in erythrocytes of G. denticulata and the activity of catalase and superoxide dismutase was higher in erythrocytes of G. carbonaria.