CC(C)C[C@H](NC(=O)N1CCn2c1nc1ccccc12)C(=O)N[C@H](Cc1ccccc1)C(=O)O
An acid's negative base-10 logarithmic dissociation constant (pKa) follows directly from its underlying thermodynamics; the negative pKa is directly proportional to its standard Gibbs free energy change. What is the negative pKa value of this molecule?