THIOL REDUCTION AND PROTAMINE EXCHANGE:

JULIANELLI VL; ROMANATO M; FARRANDO B; CALVO L; CALVO JC

Congreso; XII Jornadas Anuales de la Sociedad Argentina de Biología; 2010

Sociedad Argentina de Biología

IBYME-CONICET, FCEN-UBA. E-mail: julianelli@dna.uba.ar Previous results indicate that heparin (Hep) cooperates with glutathione (GSH) in protamine thiol reduction during human sperm decondensation. The aim of this study was to evaluate the effect of Hep on chromantin thioreduced status using a direct methodology. Isolated nuclei from normospermic donors (OMS) were incubated (37‹C) with GSH (10mM) or DTT (0.1mM) (30f) and Hep (46uM) (0, 5, 15, 30f). Chromatin thioreduced status was evaluated by fluorescence microscopy with thiol reagent monobromobimane and quantified (arbitrary units) using ImageJ. DTT was a more potent thiol reducing agent than GSH (98E}2 vs. 62E}2, ANOVA-Dunn, p<0,01). Thiol reduced status increased significantly after 5f exposure to Hep with GSH as thiol reducing agent (62E}2 vs. 102E}3, ANOVA-Dunn, p<0.001) but not with DTT. These results confirm that Hep not only behaves as protamine acceptor but also cooperates in chromatin thiol reduction by GSH, suggesting that both processes take place simultaneously.‹C) with GSH (10mM) or DTT (0.1mM) (30f) and Hep (46uM) (0, 5, 15, 30f). Chromatin thioreduced status was evaluated by fluorescence microscopy with thiol reagent monobromobimane and quantified (arbitrary units) using ImageJ. DTT was a more potent thiol reducing agent than GSH (98E}2 vs. 62E}2, ANOVA-Dunn, p<0,01). Thiol reduced status increased significantly after 5f exposure to Hep with GSH as thiol reducing agent (62E}2 vs. 102E}3, ANOVA-Dunn, p<0.001) but not with DTT. These results confirm that Hep not only behaves as protamine acceptor but also cooperates in chromatin thiol reduction by GSH, suggesting that both processes take place simultaneously.E}2 vs. 62E}2, ANOVA-Dunn, p<0,01). Thiol reduced status increased significantly after 5f exposure to Hep with GSH as thiol reducing agent (62E}2 vs. 102E}3, ANOVA-Dunn, p<0.001) but not with DTT. These results confirm that Hep not only behaves as protamine acceptor but also cooperates in chromatin thiol reduction by GSH, suggesting that both processes take place simultaneously.E}2 vs. 102E}3, ANOVA-Dunn, p<0.001) but not with DTT. These results confirm that Hep not only behaves as protamine acceptor but also cooperates in chromatin thiol reduction by GSH, suggesting that both processes take place simultaneously.