Mechanistic Explanation of the Weak Carbonic Anhydrase's Esterase Activity.

In order to elucidate the elementary mechanism of the promiscuous esterase activity of human carbonic anhydrase (h-CA), we present an accurate theoretical investigation on the hydrolysis of fully-acetylated d-glucose functionalized as sulfamate. This h-CA's inhibitor is of potential relevance in cancer therapy. The study has been performed within the framework of three-layer ONIOM (QM-high:QM'-medium:MM-low) hybrid approach. The computations revealed that the hydrolysis process is not energetically favored, in agreement with the observed weak carbonic anhydrase's esterase activity.