Can any one explain oxidized insulin?

Question

All most all the invitro expriments use the oxidized form of insulin. Sigma also have oxidized insulin A and B. Please explain what are they and their structure. Additional informations regarding this are welcome.

Answer 1

Oxidized insulin peptides have two cysteic acid residues instead of the normal cysteine residues. The -SH of cysteine residues are oxidized to sulfonic acid group to form cysteic acid.