Effect of Sodium Tetrathionate on Cyanide Conversion to Thiocyanate by Enzymatic and Non-Enzymatic Mechanisms.

摘要

Sodium tetrathionate has been proposed as a cyanide antidote despite its reported toxicology and inhibitory effect on rhodanese. We investigated the effect of tetrathionate and an analog, dithionite, on rhodanese activity because of their structural similarity to thiosulfate, a known sulfane sulfur donor for this enzyme. Rhodanese activity of guinea pig liver homogenate was assayed by measuring the formation of ferric thiocyanate complex at 460 nm. With thiosulfate as a substrate, the Km for rhodanese was 6.7 mM and the Vmax was 0.67 micro molthiocyanate min-1mg-1 protein.