Table 2.

Characteristics of zinc interactions with single amino acid side chains.

Amino Acid	Interaction	Energy (kJ/mol) *	Distance (Å)	Geometry of the Complex †
Cys	Zn–S (Cysteine)	−60.35	2.27	Tetrahedral
His	Zn–N (Imidazol)	−34.26	2.07	Octahedral
Asp, Glu	Zn–O (Carboxyl)	−4.49	2.18	Octahedral

* Theoretical values relative to water; ^† zinc complex geometry conformation with the corresponding amino acid and water molecules. Adapted from the reference by Bartosz Trzaskowski et al. [36].