Haptoglobin
From Anvita Health Wiki
Contents |
Function
- irreversibly binds alpha chain of free oxyhemoglobin
- prevents loss of iron through the kidneys & protects the kidneys from damage by hemoglobin, while making the hemoglobin accessible to degradative enzymes
- tetramer of two alpha & two beta chains formed from common precursor
- may form multimers of MW up to 1000 kD.
- normally accounts for 25% of the alpha-2 band on serum protein electrophoresis ( SPE)
- an elevated haptoglobin is the most common abnormality seen on SPE
- haptoglobin is an acute phase reactant & becomes elevated non-specifically in the presence of inflammation or tissue injury
- depressed haptoglobin levels are seen in association with hemolysis
Structure
- belongs to the peptidase S1 family
- contains 1 peptidase S1 domain
- contains 2 Sushi (CCP/SCR) domains
Compartment
Expression
Polymorphism
Notes
- although homologous to serine proteases, it has lost all essential catalytic residues & has no enzymatic activity
More General Terms
Additional Terms
Internet Database
Entrez gene: 3240
Kegg: [1]
OMIM: 140100
Prosite: [2]
Prosite: [3]
UniProt: [4]
References
- Tietz Fundamentals of Clinical Chemistry 3rd ed, WB Saunders, 1987 pg 331
- Clinical Diagnosis & Management by Laboratory Methods, J.B. Henry (ed), W.B. Saunders Co., Philadelphia, PA. 1991, pg 222
- UniProt [5]
- GeneReviews [6]
- SHMPD; Singapore Human Mutation and Polymorphism Database [7]
- Wikipedia; Note: haptoglobin entry [8]
