Lanthanides as Product Growth Modulators in Enzyme-Catalyzed Reactions

Lanthanides, known for their unique coordination chemistry, can modulate enzymatic activity by interacting with active or allosteric sites. This study investigated the effects of lanthanides on alkaline phosphatase activity, a model enzyme essential for phosphate metabolism. Reactions were conducted in 96-well microplates using a 0.1 M tris hydrochloride buffer, with sequential additions of enzyme, lanthanide, and phosphatase substrate. Product formation was monitored at 415 nm, and reaction rates were calculated using linear regression. Most lanthanides, including Cerium, Praseodymium, and Neodymium, exhibited inhibitory effects, reducing reaction rates by 12.1%, 14.8%, and 19.8%, respectively. In contrast, Europium and sodium nitrate (NaNO₃) demonstrated modest enhancements of 3.7% and 5.2%, respectively. These findings highlight the dual role of lanthanides as inhibitors and enhancers, suggesting potential applications in enzymatic engineering and biocatalysis. Further studies are needed to elucidate the molecular mechanisms underlying these interactions.