Dr. Lim, Carmay ’s Lab林小喬 博士 實驗室

Differential Role of the Protein Matrix on the Binding of a Catalytic Aspartate to Mg2+ vs Ca2+: Application to Ribonuclease H.

Divalent metal cations are essential cofactors for many enzyme functions. Although Mg²⁺ is the native cofactor in many enzymes such as ribonuclease H, its competitor Ca²⁺ may also bind to the enzyme but inhibit catalysis. Thus, the competition between Mg²⁺ and Ca²⁺ for a given metal-binding site in an enzyme and their effects on enzyme activity are of great interest. Most studies have focused on the interactions between Mg²⁺ or Ca²⁺ and the metal ligands in the first and sometimes second coordination shell.