Philip J Hogg
Disulfide bonds form as proteins fold in the cell and formation was assumed to be complete when the mature protein emerges. This is not the situation for many proteins that are constitutively produced as multiple partially disulfide-bonded states. For some proteins, thousands of different states are predicted assuming no dependencies on disulfide bond formation. In this chapter, probabilities for disulfide bond formation are employed to estimate the number of disulfide-bonded states. Situations where disulfide bond formation is independent of, or dependent on, the state of other bonds in the protein are considered. Estimates of the number of disulfide-bonded protein states will assist with the conceptual and experimental challenges of studying this biology.