The Prevention of Thiol Autoxidation in Biological Systems by Means of Thiolated Sephadex.

Abstract

The autoxidation of biologically important thiols has been prevented for periods up to 2 days in neutral and slightly alkaline solution. This is accomplished by the addition of a small quantity of the insoluble electron exchange material "thiolated Sephadex" (SH-Sephadex). The level of cysteamine, cysteine, reduced glutathione, AET and diethylcysteamine added to biological materials can be maintained constant for more than 20 h at pH 7.5 and 37[degree] in the presence of SH-Sephadex. When cupric and ferric ions are present the system is more unstable. The stabilizing effect of SH-Sephadex involves (a) prevention of the disulfide catalysed thiol autoxidation and partial removal of heavy metals, resulting in a 30 fold decreased rate of oxidation and (b) a continuous reduction of the disulfide molecules formed.