Alkaline phosphatase

Function

Alkaline phosphatase (ALP) is an enzyme which removes phosphate from nucleotides, proteins and alkaloids. The enzyme is most effective in alkaline environment. Human ALP is present as 3 tissue-associated isozymes: intestinal, tissue-nonspecific and placental (ALPP). ALP is a zinc and magnesium containing enzyme. ALP is a glycoprotein which is attached by a GPI anchor to cell surfaces.

Disease

High levels of ALP are associated with hyperphosphatasia with mental retardation syndrome.

Relevance

ALP is used in molecular biology to remove the phosphate at the 5' end of DNA thus preventing its self ligation. ALP activity is used in the dairy industry as a marker for successful pasteurization since it does not denature at temperatures which kill bacteria in milk.