Comparative study of insulin chain-B in isolated and monomeric environments under external stress.

We have conducted a series of theoretical simulations of insulin chain-B under different electric field conditions. This work extends our previous studies of the isolated chain-B by including chain-A and revealing the effects of chemical stress. For this complete protein, we observed increased stability under ambient conditions and under the application of thermal stress, compared to isolated chain-B. On the other hand, the presence of chain-A enhanced the effects of the applied electric field. Under the static field, the presence of chain-A lowered the strength of the field necessary to stretch the protein. Under the oscillating fields, there was relatively less stretching due to the competitive alignment process of the three helical regions with respect to the field. At high field strengths, we observed that the high frequency oscillating field caused less secondary structure disruption than a lower frequency field of the same strength.