Question

I have a 4 amino acid peptide of unknown sequence with a curious titration profile around pH = 6. If Iknow that the peptide N-terminus has a pKa = 9, C-terminus pKa = 3, and an obvious titration point at pH= 10.5, what amino acid could likely generate a strange titration profile at pH 6 in this peptide?a. Cysteineb. Tyrosinec. Histidined. Arginine

Answer 1

c. Histidine

Step-by-step explanation:

Histidine is a compound that is normally used for the generation of protein. Three amino acids commonly have basic side chain when the pH is neutral. The conjugate acid in histidine has a pKa of approximately 6. Based on the description of the experimental analysis provided in the statement, the right option is option c.