Analysis of the extent of unfolding of denatured insulin-like growth factor

Insulin-like growth factor (IGF-1) contains three disulfide bonds. In the p resence of denaturant and thiol catalyst, IGF-1 shuffles its native disulfi de bends and denatures to form a mixture of scrambled isomers. The composit ion of scrambled IGF varies under different denaturing conditions. Among th e 14 possible scrambled IGF isomers, the yield of the beads-form isomer is shown to be directly proportional to the strength of the denaturing conditi on. This paper demonstrates a new approach to quantify the extent of unfold ing of the denatured protein.