Comparative Studies of the Physicochemical Properties of 3-Mercaptopyruvate Sulfurtransferase (3-MST) from Pennisetum glaucum (Millet) and Sorghum bicolor (Guinea corn)

Abstract

3-Mercaptopyruvate sulfurtransferase (3-MST) is a cyanide detoxifying enzyme that helps in the detoxification of cyanide to a less toxic thiocyanate. 3-MST was purified from the seeds of Sorghum bicolor and Pennisetum glaucum. The enzyme was purified from the seeds by 80% ammonium sulphate precipitation and ion exchange chromatography on CM-Sephadex C-25. The Enzyme from Sorghum bicolor had a specific activity of 0.056 U/mg with a yield of 23.86 % while Pennisetum gluacum had specific activity and percentage yield of 0.0445 U/mg and 27.90% respectively. The Optimum pH of the enzyme from Sorghum bicolor and Pennisetum glaucum was observed at 6.0 and 8.0 respectively, while the optimum temperature was observed at 50 ^oC. The results of the inhibition studies revealed that there was no significant effect of the metal ions on the enzyme activity. The study confirmed the presence of 3-MST, a powerful cyanide detoxification mechanism in the seeds of Sorghum bicolor and Pennisetum glaucum.