Question

You are given a peptide Ala-Cys-Leu that is oxidized to form a disulfide bond with another Ala-Cys-Leu. What is its net charge at pH 12? What is its net charge if the disulfide bonds are reduced?

Answer 1

A.) When disulfide bonds are formed:

(Two peptide together)

о но не NET - СН – – – СН – С – – CH – C00- I CH, CH, CH, CH се, сна он CH₂ сH — Соо N, - сH — с-м — сH — с 2-т CH, сH сH, CH,

At pH 12, net charge = 0

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B.) When disulfide bonds are reduced:

(For one peptide only)

он он CH- C-N-CH - -О Coo- NH, - сH – С. CH, сH, CH s® Removed Сн, , рН – а

At pH 12, net charge = -1

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