NCCC[C@@H](CC(=O)N[C@@H]1CCCC[C@H]1C(=O)N[C@H](CC(=O)N[C@@H](CCC(=O)O)CC(=O)O)Cc1c[nH]c2ccccc12)NC(=O)C[C@H](CO)NC(=O)[C@@H]1CCCC[C@H]1N
The negative base-10 logarithmic of dissociation constant (pka) for an acid is a direct consequence of the underlying thermodynamics of the dissociation reaction; the pKa value is directly proportional to the standard Gibbs free energy change for the reaction. What is the pka value of this molecule?