Fosfataser

Fosfataser are a broad class of enzymes that catalyze the hydrolysis of phosphate esters, removing phosphate groups from a wide range of substrates including proteins, nucleotides, sugars and lipids. By changing the phosphorylation state of molecules, they play a key role in regulating metabolic pathways, signal transduction and cellular processes. Fosfataser are found across many organisms, from bacteria to humans, and exist in several distinct families with different pH optima and cellular localizations.

The two most studied groups in humans are the alkaline phosphatases and the acid phosphatases. Alkaline phosphatases function best at alkaline pH and are often associated with the extracellular matrix or the cell surface; they include tissue-nonspecific alkaline phosphatase and isoenzymes such as intestinal and placental alkaline phosphatases. Acid phosphatases operate at acidic pH and are typically lysosomal enzymes. Many fosfataser require metal ions, commonly magnesium or zinc, as cofactors for activity. They can be membrane-bound, secreted, or intracellular, reflecting diverse biological roles.

Physiologically, fosfataser contribute to bone mineralization, fatty acid metabolism, and the regulation of signaling pathways by reversing phosphorylation. They help recycle phosphate groups and can modulate enzyme activity, receptor function and gene expression. Clinically, blood levels of alkaline phosphatase are used as a marker for liver or bone disorders, while specific acid phosphatases have historical roles as tumor markers in certain cancers.

In molecular biology, alkaline phosphatase is widely used to dephosphorylate DNA ends to prevent unwanted ligation during cloning, with various commercial enzymes available for laboratory applications.