The Alkaline Assassin: L-Leucine as Human Placental Alkaline Phosphatase Inhibitor
Alkaline Phosphatase (AP) is an enzyme that catalyzes the hydrolysis of phosphomonoesters to produce phosphate and alcohol. Alkaline phosphatase has isoenzymes: placental alkaline phosphatase (PLAP), germ cell alkaline phosphatase (GCAP). PLAP expression has been attributed with different types of cancer progression and diagnosis and is a membrane-bound protein, making it accessible cancer therapies using drugs (Basiri et al., 2021). The purpose of our project is to finding the specificity and kinetic activity of L-leucine as a human PLAP inhibitor. Previous findings reported the inhibition of GCAP by L-leucine (Bassi et al., 2021). We hypothesize that L-leucine will have similar inhibitory effects on human PLAP due to the relatedness of the two AP isoenzymes, GCAP and PLAP. PLAP activity in the presence and absence of L-leucine were determined using enzyme activity assays with p-nitrophenol as a substrate and measuring the absorbance at 410 nm. The kinetic parameters indicated L-leucine as an uncompetitive inhibitor of PLAP. Results suggested the use of high L-leucine concentrations does in fact exhibit inhibitory effects, where the Vmax dropped to half the reported Vmax of PLAP.
- Biological Sciences