Auto-oxidation of Lingula unguis and Siphonosoma cumanense hemerythrins induced by some perturbants.

Auto-oxidation of human adult hemoglobin and Siphonosoma cumanense and Lingula unguis hemerythrins were investigated in the presence and absence of perturbants. In the presence of urea, there were no drastic increases in auto-oxidation rates for the three proteins. In contrast, thiocyanate and laurate enhanced the auto-oxidation rates remarkably. In the presence of thiol reagents such as PCMB and NEM, auto-oxidation rates were enhanced with dissociation into subunit, but not enhanced so much with SH-modification only. Thus oligomerization is probably necessary to protect auto-oxidation.