The Complete Amino‐Acid Sequence of Hen Ovalbumin

Abstract

The complete amino acid sequence of hen ovalbumin, comprising 385 residues, has been determined. The sequence was deduced from the 17 cyanogen bromide fragments and from peptides derived by digestion with a number of proteolytic enzymes. The molecular weight of the polypeptide chain of ovalbumin is 42699.Ovalbumin has four sites of postsynthetic modification ; in addition to the acetylated N terminus, the carbohydrate moiety is located at Asn-292, and the two phosphorylated serines are at residues 68 and 344. The 'signal sequence' of ovalbumin is between residues 234 and 252. The heptapeptide released during the conversion of ovalbumin to plakalbumin by subtilisin digestion corresponds to residues 346 -352. The hen ovalbumin polymorphism characterised by an Asn-tAsp replacement results from a mutation at residue 31 1.The amino acid sequence of ovalbumin deduced from these amino acid sequence studies is in complete agreement with the sequence of mRNA determined by McReynolds et al. [Nature (Lond.) 273, 723 -728 (1978)].Ovalbumin is the most abundant protein in egg white, and is readily purified and crystallised in gram quantities [l].

Structural Characteristics of Hen Egg Ovalbumin Expressed in YeastPichia pastoris

“…Hen egg OVA is known to contain two potential N-glycosylation sites, at Asn-292 and Asn- 311, whereas it exists in a singly N-glycosylated form with a carbohydrate chain on Asn-292 in hen egg white. 1,3) In addition, Kato et al 17,18) isolated and characterized biosynthetic intermediates of hen egg OVA, one of which was shown to have been di-Nglycosylated only transiently at both of Asn-292 and Asn-311 in the hen oviduct. Hence the difference in molecular size between components H and L might be due to the difference in the number of the attached carbohydrate chain.…”

“…1,2,4) It also exists in three forms, A 1 -, A 2 -, and A 3 -OVA with two, one, and no phosphate groups per molecule respectively. 1,2,5) Most of hen egg OVA is of the A 1 -form. 6) This protein is widely used as an food ingredient by the food industry to enhance and improve the functionality of various food products.…”

“…It is a globular, acidic protein which comprises a single polypeptide chain of 385 amino acid residues with a molecular weight of 45 kDa and has a single carbohydrate chain linked to Asn-292 [1][2][3] and an acetyl group at the N-terminus. 1,2,4) It also exists in three forms, A 1 -, A 2 -, and A 3 -OVA with two, one, and no phosphate groups per molecule respectively. 1,2,5) Most of hen egg OVA is of the A 1 -form.…”

Site-specific de- N -glycosylation of diglycosylated ovalbumin in hen oviduct by endogenous peptide: N -glycanase as a quality control system for newly synthesized proteins

“…OVA is a major protein component of egg white, and is known to contain two potential Nglycosylation sites at Asn-292 and Asn-311 (19,20), while a single carbohydrate chain is attached only on the Asn-292 residue of the secreted genuine OVA (20,21). Kato et al (18,22) isolated and characterized biosynthetic intermediates of OVA, and one of which was shown to be di-N-glycosylated at both Asn-292 and Asn-311.…”

Chip Electrophoresis as a Method for Quantifying Total Albumin in Cerebrospinal Fluid

“…Serving as an internal standard, a constant amount of CA was added to each CSF sample before assaying on the chip (final concentration of 60 mg/L). As illustrated in a representative electropherogram of patient CSF, human albumin (HA, 66 kDa) and CA (44 kDa) 26,27 clearly resolved from each other ( Fig. 2A).…”