High-performance liquid chromatography of insulin: accessibility and flexibility

Current ideas suggest that a conformational change in the insulin monomer may play an important part in its interaction with the insulin receptor. An investigation is reported in which analytical reversed-phase high-performance liquid chromatography of insulin analogues was used to investigate the solution conformation of the insulin monomer. The results are interpreted in terms of elution coefficients modified by the calculated surface accessibilities of individual residues. The results suggest a partial unfolding of the insulin monomer under the experimental conditions used, which is consistent with current ideas on the biologically active conformation of insulin.