Regeneration of insulin monomers from amyloid fibrils by a NH_3/H_2O_2 two-step method

摘要

We have developed a NH_3/H_2O_2 two-step method for the recovery of insulin monomers from amyloid fibrils by modulating the cleavage and regeneration of disulfide bonds. Insulin fibrils were disaggregated into insulin A- and B-chains in 14 M (w/v) NH_4OH for 2 h at 60 degC. Insulin monomers, with a MW of ~ 5,882 Da, were then regenerated by oxidation of sulfhydryls with 30 % (w/v) H_2O_2 (10 M) for 12 h at 25 degC. No two A-chains or two B-chains of insulin formed during the oxidation process. Because of the inconformity of the optimal reduction and oxidation temperature, the NH_3/H_2O_2 two-step method is more practical than the NH_3/H_2O_2 coupling method.