Alkaline phosphatase (ALP, ALKP, ALPase, Alk Phos) (EC 3.1.3.1) or basic phosphatase is a homodimeric protein enzyme of 86 kilodaltons. Each monomer contains five cysteine residues, two zinc atoms, and one magnesium atom crucial to its catalytic function, and it is optimally active at alkaline pH environments. As its name indicates, ALP functions best under alkaline pH environments and has the physiological role of dephosphorylating compounds

1. Alkaline Phosphatase
- Alex Thomas
Basics

2. Do you know?
• Why the name alkaline phosphatase?
• Why Blood levels of alkaline phosphatase increase two to four times
during pregnancy?
• Relation between ALP and the scoring method?
• What are the Alkaline phosphatase isozymes in Humans?
• During childhood the majority of alkaline phosphatase are of skeletal
origin
• ALP is heat stable
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3. Behind the name
 ALP functions best under alkaline pH environments and has the
physiological role of dephosphorylating compounds.
 A phosphatase is an enzyme that uses water to cleave a phosphoric
acid monoester into a phosphate ion and an alcohol
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4. Why Blood levels of alkaline phosphatase increase two to four
times during pregnancy?
 Additional alkaline phosphatase produced by the placenta
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5. Alkaline phosphatase isozymes in Humans?
Humans and most other mammals contain the following alkaline
phosphatase isozymes:
 ALPI – intestinal (molecular weight of 150 kDa)
 ALPL – tissue-nonspecific (expressed mainly in liver/bone/kidney)
 ALPP – placental (Regan isozyme)
 GCAP – germ cell
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6. Source
 In humans, alkaline phosphatase is present in all tissues throughout
the entire body, but is particularly concentrated in the
 Liver
 Bile Duct
 Kidney
 Bone
 Intestinal Mucosa
 Placenta
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7. Elevated levels
 Biliary obstruction
 Bone conditions
 Osteoblastic bone tumors
 Osteomalacia
 Osteoporosis
 Hepatitis
 Cirrhosis
 Myelofibrosis
 Leukemoid reaction
 Lymphoma
 Paget's disease
 Sarcoidosis
 Hyperthyroidism
 Hyperparathyroidism
 Myocardial infarction
 Pregnancy
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8. Lowered level
 Hypophosphatasia, an autosomal recessive disease
 Postmenopausal women receiving estrogen therapy because of aging
 Men with recent heart surgery, malnutrition, magnesium deficiency, hypothyroidism, or
severe anemia
 Children with achondroplasia and cretinism
 Children after a severe episode of enteritis
 Pernicious anemia
 Aplastic anemia
 Chronic myelogenous leukemia
 Wilson's disease
 Hypothyroidism
 Pernicious anaem
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9. Thank you
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