Estimation of the deamidation rate of asparagine side chains

Statistical analysis of data from the literature concerning the deamidation reaction of asparagine side-chains in short peptides reveals that the logarithm of rate constants can be solved into a constant plus contributions from the residues closest to asparagine. A table of amino acid contributions has been derived, from which deamidation rate constants can be estimated with good approximation. Assuming the contribution of glycine to be zero, the mean of the absolute values of the contributions for the residues following asparagine is approximately seven times that for the preceding residues. In both positions residues with no bulk side chains or with functional side groups contribute markedly to the increase in the rate constant.