Interaction of Cob(III)alamins with Hypothiocyanite. Evidence for the Formation of Hypothiocyanitocobalamin

Here, we report the results of investigation of the reactions between cobalamins (Cbls) and hypothiocyanite (OSCN-), a product of thiocyanate oxidation by hydrogen peroxide in the presence of lactoperoxidase. In the case of aquacobalamin, the product, the UV-vis spectrum of which differs from the UV-vis spectra of Cbl(III)-complexes with SCN-, SO32-, OCN- and CN- anions, is formed and attributed to hypothiocyanitocobalamin. This complex reacts with selenomethionine at substantially lower rate than the free OSCN-. Cyano- and methyl-Cbls are relatively stable in the presence of OSCN-. Glutathionylcobalamin is transformed to hypothiocyanitocobalamin in the presence of OSCN- excess via the oxidation of glutathionyl-ligand and subsequent binding of OSCN- by Cbl(III).

Automated summary

The study investigated the reactions between cobalamins and hypothiocyanite (OSCN-), showing that different types of cobalamins react differently in the presence of OSCN-. The formation of hypothiocyanitocobalamin is influenced by various factors, such as the type of cobalamin and the presence of other ligands.