Ovalbumin

Ovalbumin

Ovalbumin is the main protein found in egg white, making up 60-65% of the total protein.[1] Ovalbumin displays sequence and three-dimensional homology to the serpin superfamily, but unlike most serpins it is not a serine protease inhibitor.[2] The function of ovalbumin is unknown, although it is presumed to be a storage protein.[3]

Contents

Research

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

  • general studies of protein structure and properties (because it is available in large quantities).
  • studies of serpin structure and function (the fact that ovalbumin does not inhibit proteases means that by comparing its structure with that of inhibitory serpins, the structural characteristics required for inhibition can be determined).
  • immunology (commonly used to stimulate an allergic reaction in test subjects, e.g. established model allergen for airway hyper-responsiveness AHR).

(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]

Structure

The ovalbumin protein of chickens is made up of 385 amino acids, and its relative molecular mass is 45 kDa.[4] It is a glycoprotein with 4 sites of glycosylation.[4]

It is secreted from the cell. Unlike the signal sequences of most secreted proteins, Ovalbumin's signal sequence is not cleaved. Additionally it is not located directly on the N-terminus, but rather internally, starting at residue 21 and ending at residue 47.[5]

Medicinal characteristics

In cases where poisoning by heavy metals (such as Iron) is suspected, ovalbumin may be administered.[6] Ovalbumin chelates to heavy metals and traps the metal ions within the sulfhydryl bonds of the protein. Chelating prevents the absorption of the metals into the gastrointestinal tract and prevents poisoning.

See also

References

  1. ^ Huntington JA, Stein PE (2001) Structure and properties of ovalbumin. Journal of Chromatography B 756(1-2): 189-198.
  2. ^ Hu H.Y., Du H.N. (2000). "Alpha to Beta Structural Transformation of Ovalbumin: Heat and pH Effects". Journal of Protein Chemistry 19 (3): 177–183. doi:10.1023/A:1007099502179. PMID 10981809. 
  3. ^ Gettins PGW (2002) Serpin structure, mechanism, and function. Chemical Reviews 102(12): 4751-4804.
  4. ^ a b Nisbet AD, Saundry RH, Moir AJG, Fothergill LA, Fothergill JE (1981) The complete amino-acid sequence of hen ovalbumin. European Journal of Biochemistry 115(2): 335.
  5. ^ Robinson A, Meredith C, Austen BM (1986) Isolation and properties of the signal region from ovalbumin. FEBS Letters 203(2): 243-246.
  6. ^ Dominiczak M, Baynes J, Medical Biochemistry, 2d edition (2004), p59.

External links


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Look at other dictionaries:

  • Ovalbumin — (Gallus gallus) Bändermodell von zwei Seiten nach PDB  …   Deutsch Wikipedia

  • Ovalbumin — O val*bu min ([=o] v[a^]l*b[=u] m[i^]n), Ovalbumen O val*bu men ([=o] v[a^]l*b[=u] m[e^]n), n. [Ovum + albumin.] (Physiol. Chem.) The albumin from white of eggs; egg albumin; in distinction from {serum albumin}. See {Albumin}. [1913 Webster] …   The Collaborative International Dictionary of English

  • ovalbumin — noun Date: circa 1836 1. the principal albumin of white of egg; especially the crystalline part of egg albumins 2. dried whites of eggs …   New Collegiate Dictionary

  • ovalbumin — A major protein constituent of egg white. A phosphoprotein of 386 amino acids (44 kD) with one N linked oligosaccharide chain. Synthesis is stimulated by oestrogen. The gene, of which there is only one in the chicken genome, has eight exons and… …   Dictionary of molecular biology

  • ovalbumin — /ov al byooh min, oh val /, n. Biochem. the principal protein of egg white. [1825 35; contr. and respelling of LL ovi albumen (L ovi album) egg white; see OVUM, ALBUMEN] * * * …   Universalium

  • ovalbumin — noun A glycoprotein which is the primary constituent of egg white …   Wiktionary

  • ovalbumin — The chief protein occurring in the white of egg and resembling serum albumin; also found in phosphorylated form. SYN: albumen, egg albumin. * * * ov·al·bu·min .äv al byü mən, .ōv n the principal albumin of white of egg called also egg albumin …   Medical dictionary

  • Ovalbumin — Ov|al|bu|min [↑ Ovo u. ↑ Albumin] ein phosphoryliertes Glykoprotein als Hauptprotein (↑ Serpin) des Eiklars, MG 44 500, mit 385 Aminosäureresten u. 3,2 % Kohlenhydraten (Mannose u. Glucosamin) …   Universal-Lexikon

  • Ovalbumin — Ov|al|bu|min* das; s, e <zu ↑ovo... u. ↑Albumin> Eiweißkörper des Eiklars …   Das große Fremdwörterbuch

  • ovalbumin — [əʊ valbjʊmɪn] noun Biochemistry albumin from the white of eggs. Origin C19: from L. ovi albumen albumen of egg , alt. on the pattern of albumin …   English new terms dictionary

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