Oxidative sulfitolysis

J. S. Pati ick and A. L. Lagu, Determination of recombinant human proinsulin fusion protein produced in Escherichia coli using oxidative sulfitolysis and two-dimensional HPLC, Chem. 64 507-511 (1992). 

By oxidative sulfitolysis. Originally this method was conceived as involving (i) fission of disulfide by sulfite to produce thiol and S-sulfo-cysteine, and (ii) oxidation of this thiol to disulfide which again reacts with sulfite as in (i). The over-all reaction is the conversion of disulfide to >S-sulfocysteine. On this basis the reactions can be formulated as in reaction (II). 

Sulfonate derivatives of cysteine peptides, also referred to as Bunte salts, are prepared by oxidative sulfitolysis of cysteine or cystine peptides (Scheme These derivatives... 

Oxidative decarboxylations. See Decarboxylation Oxidative -elimination. See ( Elimination Oxidative sulfitolysis, 239-240. V-, P- and 5-Oxides deoxygenation, 115 Oximes Beckmann rearr., 136-137 heterocycles from, 307-308 reduction of, 98, 112 Oxirane (ethylene oxide) ... 

Kella, N.K.D. Y.J. Kang J.E. Kinsella. Effect of oxidative sulfitolysis of disulfide bonds of bovine serum albumin on its structural properties./. Protein Chem. 1998, 7, 535-548. 

Sulfitolysis is another means by which the disulfide bond is broken by some fungi. This reaction occurs in the presence of sulfite and under alkaline conditions. It cleaves the disulfide in cystine to S-sulfocysteine and cysteine [74, 75]. This causes the keratin chains to denature by releasing them from one another (chaini-S-S-chain2-I- SO3" chaini-S-S03 -1- S-chain2). The fungal oxidation of thiols in the cysteine residues yields sulfide for this reaction, and the liberation of ammonium from the deamination of the amino acids creates the alkaline conditions to help drive this reaction [76]. 

Fig, 2. Cleavage and resynthesis of insulin (1) oxidative sulfitolysis and isolation of the S-sulfonated A and B chains (2) conversion of the S-sulfonated chains to their sulfhydryl form ... 

Fig. 3. Resynthesis of insulin by the improved method (Katsoyannis and Tometsko, 1966) (1) oxidative sulfitolysis ...

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