How do you determine amino acid sequences from Pka values?

Answer 1

The short answer is that you can't. Individual amino acids may be identified by their pI, the point at which they have an overall neutral charge, but finding the pKa of a protein as a whole can't conclusively give you the amino acid sequence of the protein. You may get a sense of whether the protein is acidic or basic overall though.

There may be some way to do it if you have other factors involved in your experiment that you haven't divulged (i.e., a limited number of sequences that could be the answer or controls in the experiment), but the simple answer to your question is that it is impossible.

Source:

Three years of a Biochem degree

Answer 2

To determine amino acid sequences from pKa values, you can use the known pKa values of the amino acids to predict their charge state at a specific pH. Based on the charge states, you can then infer the amino acid sequence by looking at the known pKa values and comparing them to the charge states at the given pH. Additionally, tools like bioinformatics software can be used to assist in predicting the amino acid sequence from pKa values.