Ovalbumin
Structure of ovalbumin (PDB: 1OVA​)
Identifiers
OrganismGallus gallus
Symbol?
UniProtP01012
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StructuresSwiss-model
DomainsInterPro

Ovalbumin (abbreviated OVA[1]) is the main protein found in egg white, making up approximately 55% of the total protein.[2] Ovalbumin displays sequence and three-dimensional homology to the serpin superfamily, but unlike most serpins it is not a serine protease inhibitor.[3] The function of ovalbumin is unknown, although it is presumed to be a storage protein.[4]

Research

Ovalbumin is an important protein in several different areas of research, including:

(For in vivo and in vitro studies based on ovalbumin it is important that the endotoxin content is less than 1 EU/mg.)[citation needed][needs context]

Structure

The ovalbumin protein of chickens consists of 385 amino acids, its relative molecular mass is 42.7 kDa,[5] and it adopts a serpin-like structure.[6] Ovalbumin also has several modifications, including N-terminal acetylation (G1), phosphorylation (S68, S344), and glycosylation (N292).[5] It has three isoforms, A1, A2, and A3, which vary based on the number of bound phosphate residues.[7] It is secreted from the cell, targeted by an internal signal sequence (residues 21–47), rather than the N-terminal signal sequence commonly found in other secreted proteins. Ovalbumin's signal sequence is not cleaved off, but remains as part of the mature protein.[8]

Change upon heating

When heated, ovalbumin undergoes a conformational change from its soluble, serpin structure into an insoluble all-β-sheet structure with exposed hydrophobic regions. This causes the protein to aggregate and cause the solidification associated with cooked egg white.[9]

See also

References

  1. ^ Sano K, Haneda K, Tamura G, Shirato K (June 1999). "Ovalbumin (OVA) and Mycobacterium tuberculosis bacilli cooperatively polarize anti-OVA T-helper (Th) cells toward a Th1-dominant phenotype and ameliorate murine tracheal eosinophilia". American Journal of Respiratory Cell and Molecular Biology. 20 (6): 1260–7. doi:10.1165/ajrcmb.20.6.3546. PMID 10340945. S2CID 22811888.
  2. ^ Sugino H, Nitoda T, Juneja LR (1996-12-13). "Chapter 2: General Chemical Composition of Hen Eggs". In Yamamoto T, Juneja LR, Hatta H, Kim M (eds.). Hen eggs. Boca Raton, FL: CRC Press. ISBN 978-0-8493-4005-5.
  3. ^ Hu HY, Du HN (April 2000). "Alpha-to-beta structural transformation of ovalbumin: heat and pH effects". Journal of Protein Chemistry. 19 (3): 177–83. doi:10.1023/A:1007099502179. PMID 10981809. S2CID 82745511.
  4. ^ Gettins PG (December 2002). "Serpin structure, mechanism, and function". Chemical Reviews. 102 (12): 4751–804. doi:10.1021/cr010170. PMID 12475206.
  5. ^ a b Nisbet AD, Saundry RH, Moir AJ, Fothergill LA, Fothergill JE (April 1981). "The complete amino-acid sequence of hen ovalbumin". European Journal of Biochemistry. 115 (2): 335–45. doi:10.1111/j.1432-1033.1981.tb05243.x. PMID 7016535.
  6. ^ Stein PE, Leslie AG, Finch JT, Carrell RW (October 1991). "Crystal structure of uncleaved ovalbumin at 1.95 A resolution". Journal of Molecular Biology. 221 (3): 941–59. doi:10.1016/0022-2836(91)80185-W. PMID 1942038.
  7. ^ Sugimoto, Yasushi (April 1999). "Ovalbumin in Developing Chicken Eggs Migrates from Egg White to Embryonic Organs while Changing Its Conformation and Thermal Stability*". Journal of Biological Chemistry. 274 (16).
  8. ^ Robinson A, Meredith C, Austen BM (July 1986). "Isolation and properties of the signal region from ovalbumin". FEBS Letters. 203 (2): 243–6. doi:10.1016/0014-5793(86)80751-7. PMID 3732511. S2CID 10064866.
  9. ^ Hu HY, Du HN (April 2000). "Alpha-to-beta structural transformation of ovalbumin: heat and pH effects". Journal of Protein Chemistry. 19 (3): 177–83. doi:10.1023/A:1007099502179. PMID 10981809. S2CID 82745511.

External links

Serpins
Globular proteins
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