Question

Calculate the number of disulfide bond arrangements possible for each of the polypeptides listed below, assuming that each of the cysteine residues forms a disulfide bridge. Also assume that all disulfide bridges are intramolecular, not intermolecular. a. a polypeptide with four cysteines b. a polypeptide with six cysteines c. a polypeptide with 8 cysteines d. a polypeptide with 10 cysteines hint: your answer in part a should provide you with a shortcut to calculating your answer in part b, your answer in part b should provide you with a shortcut to calculating your answer in part c, and so on.

I've seen a post that answers this question with a calculation i = (n-1)*(n-3)*(n-5)... 1. But I don't understand where this calculation came from and I can't visualize what's happening. I need help understanding this. Thanks

Answer 1

Ans - intramolecular means disulfide linkage between same peptide