Conformational dynamics of the enzyme-substrate complex of protein kinase A with pseudosubstrate SP20 and adenosine triphosphate.

The phosphorylation reaction, catalyzed by the enzyme protein kinase A (PKA), plays one of the key roles in the work of the glutamatergic system, primarily involved in memory functioning. The analysis of the dynamic behavior of the enzyme-substrate complex allows one to learn the mechanism of the enzymatic reaction. According to the results of classical molecular dynamics calculations followed by hierarchical clustering, the most preferred proton acceptor during the phosphorylation reaction catalyzed by PKA is the carboxyl group of the amino acid residue Asp166; however, the γ-phosphate group of ATP can also act as an acceptor.