Biology:Orosomucoid

From HandWiki
Short description: Acute phase protein found in plasma
orosomucoid 1
Identifiers
SymbolORM1
NCBI gene5004
HGNC8498
OMIM138600
RefSeqNM_000607
UniProtP02763
Other data
LocusChr. 9 q31-qter
orosomucoid 2
Identifiers
SymbolORM2
NCBI gene5005
HGNC8499
OMIM138610
RefSeqNM_000608
UniProtP19652
Other data
LocusChr. 9 q31-qter

Orosomucoid (ORM) or alpha-1-acid glycoprotein (α1AGp,[1] AGP or AAG) is an acute phase protein found in plasma. It is an alpha-globulin glycoprotein and is modulated by two polymorphic genes. It is synthesized primarily in hepatocytes and has a normal plasma concentration between 0.6–1.2 mg/mL (1–3% plasma protein).[2] Plasma levels are affected by pregnancy, burns, certain drugs, and certain diseases, particularly HIV.[2]

The only established function of ORM is to act as a carrier of basic and neutrally charged lipophilic compounds. In medicine, it is known as the primary carrier of basic (negatively charged) drugs (whereas albumin carries acidic (positively charged) and neutral drugs), steroids, and protease inhibitors.[2][3] Aging causes a small decrease in plasma albumin levels; if anything, there is a small increase in alpha-1-acid glycoprotein. The effect of these changes on drug protein binding and drug delivery, however, appear to be minimal.[4] AGP shows a complex interaction with thyroid homeostasis: AGP in low concentrations was observed to stimulate the thyrotropin (TSH) receptor and intracellular accumulation of cyclic AMP. High AGP concentrations, however, inhibited TSH signalling.[5][6]

Alpha-1-acid glycoprotein has been identified as one of four potentially useful circulating biomarkers for estimating the five-year risk of all-cause mortality (the other three are albumin, very low-density lipoprotein particle size, and citrate).[7]

Orosomucoid increases in amount in obstructive jaundices while diminishes in hepatocellular jaundice and in intestinal infections.

See also

Alpha-1 antitrypsin deficiency

Alpha-1 antitrypsin

References

  1. Logan, Carolynn M.; Rice, M. Katherine (1987). Logan's Medical and Scientific Abbreviations. Philadelphia: J. B. Lippincott Company. p. 3. ISBN 0-397-54589-4. https://archive.org/details/logansmedicalsci00loga/page/3. 
  2. 2.0 2.1 2.2 "Orosomucoid (alpha1-acid glycoprotein) plasma concentration and genetic variants: effects on human immunodeficiency virus protease inhibitor clearance and cellular accumulation". Clinical Pharmacology and Therapeutics 80 (4): 307–18. October 2006. doi:10.1016/j.clpt.2006.06.006. PMID 17015049. 
  3. "pH-dependency of basic ligand binding to alpha 1-acid glycoprotein (orosomucoid)". The Biochemical Journal 280 ( Pt 1) (1): 277–80. November 1991. doi:10.1042/bj2800277. PMID 1741754. 
  4. "Anesthesia for the Older Patient". Clinical Anesthesia. Lippincott Williams & Wilkins. 2009. p. 879. ISBN 978-0-7817-8763-5. 
  5. "The influence of alpha1-acid glycoprotein (orosomucoid) and its glycoforms on the function of human thyrocytes and CHO cells transfected with the human TSH receptor". Molecular and Cellular Endocrinology 188 (1–2): 241–51. February 2002. doi:10.1016/s0303-7207(01)00650-5. PMID 11911961. 
  6. "TSH and Thyrotropic Agonists: Key Actors in Thyroid Homeostasis". Journal of Thyroid Research 2012: 351864. 2012. doi:10.1155/2012/351864. PMID 23365787. 
  7. "Biomarker profiling by nuclear magnetic resonance spectroscopy for the prediction of all-cause mortality: an observational study of 17,345 persons". PLOS Medicine 11 (2): e1001606. February 2014. doi:10.1371/journal.pmed.1001606. PMID 24586121. 

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