Alkaline phosphatase

Alkaline phosphatase (ALP) is a hydrolase enzyme responsible for removing phosphate groups in the 5- and 3- positions from many types of molecules, including nucleotides, proteins, and alkaloids. The process of removing the phosphate group is called dephosphorylation. Alkaline phosphatases are most effective in an alkaline environment.

In humans, alkaline phosphatase is present in all tissues throughout the entire body, but is particularly concentrated in the liver, bile ducts, bile, bone, and the placenta.

The most common alkaline phosphatases used in research are:

• Bacterial alkaline phosphatase (BAP), from Escherichia coli C4 cells
• Shrimp alkaline phosphatase (SAP), from a species of arctic shrimp (Pandalus borealis)
• Calf intestine alkaline phosphatase (CIAP), from calf intestine

Improper blood plasma (serum) levels of ALP for a person's particular age and gender are typically indicative of disease or a fractured bone.