Covalent structure of a low-molecular-mass protein, meleagrin, present in a turkey (Meleagris gallopavo) ovomucoid preparation.
A low-molecular-mass protein, tentatively named meleagrin, was isolated from a commercial preparation of turkey (Meleagris gallopavo) ovomucoid. This 40-amino acid protein contains 3 disulfide bonds and high concentrations of aromatic residues (2 tryptophans and 3 tyrosines). It lacks threonine, methionine, phenylalanine, and arginine residues. The complete amino acid sequence was determined to be the following: less than Glu-Val-Leu-Lys-Tyr-Cys-Pro-Lys-Ile-Gly-Tyr-Cys-Ser-Ser-Lys-Cys-Ser-Lys- Ala- Glu-Val-Trp-Ala-Tyr-Ser-Pro-Asp-Cys-Lys-Val-His-Cys-Cys-Val-Pro-Ala-Asn- Gln-Lys - Trp. One of the three disulfide bonds exists between Cys12 and Cys28, and the two others links Cys32-Cys33 with Cys6 and Cys16. The amino acid sequence of meleagrin shows a strong homology to a similar basic protein, cygnin (Simpson, G.R. & Morgan, F.J. [1983] Int. J. Pep. Protein Res. 22, 476-481), of a rather distantly related aves, black swan (Cygnus atratus), suggesting some vital role of this protein in avian eggs. Similarity to a part (exon 9) of transferrins was also recognized.
Department of Biochemistry, Niigata University School of Medicine.
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Odani
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Koide
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Ono
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Takahashi
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Suzuki
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002918:Chymotrypsin; D004220:Disulfides / Q000032:analysis; D004527:Egg Proteins / Q000032:analysis*; D008969:Molecular Sequence Data; D010059:Ovomucin / Q000032:analysis*; D010446:Peptide Fragments / Q000032:analysis / Q000302:isolation & purification; D014357:Trypsin; D014422:Turkeys / Q000378:metabolism*
D000596:Amino Acids; D004220:Disulfides; D004527:Egg Proteins; D010446:Peptide Fragments; D010059:Ovomucin; C060672:meleagrin; D002918:Chymotrypsin; D014357:Trypsin