Molecular Species of Glycerophosphatides and Triglycerides of Egg Yolk Lipoproteins

Four major density classes of lipoproteins were isolated from hen's egg yolk by conventional ultracentrifugation and each class was subjected to thin-layer chromatography on hydroxylapatite. Lipid extracts were obtained from the total egg yolk, the density classes recovered at each stage of centrifugation and from the fractions resolved on hydroxylapatite. The proportions of the lipid classes in the total lipid extracts were determined by direct gas chromatography. The molecular species of the glycerides and phospholipids were identified by means of specific enzymic hydrolyses following isolation of the lipid classes by thin-layer chromatography.The results indicate that the major differences in the lipid composition of the egg yolk lipoproteins are confined to variations in the proportions of cholesterol, triglycerides, and phospholipids. There are lesser differences in the proportions of the various phospholipid classes among the different lipoproteins. All lipoprotein classes, except the water-soluble fraction, contained the same species of each phospholipid and triglyceride. The lipids of the water-soluble fraction were more saturated than those of the other lipoproteins.

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Resolution of Egg Yolk Lipoproteins by Chromatography on Thin Layers of Hydroxylapatite

Canadian Journal of Biochemistry ◽

10.1139/o71-008 ◽

1971 ◽

Vol 49 (1) ◽

pp. 44-50 ◽

Cited By ~ 6

Author(s):

D. A. Gornall ◽

A. Kuksis

Keyword(s):

Soluble Fraction ◽

Protein Composition ◽

Egg Yolk ◽

Thin Layers ◽

Water Soluble ◽

Low Density ◽

Density Fraction ◽

Composition And Structure ◽

Layer Chromatography ◽

Egg Yolk Lipoproteins

Egg yolk lipoproteins were separated into four major density classes by conventional ultracentrifugation, and each class was resolved further by thin-layer chromatography on hydroxylapatite. The plates were developed in special saturation chambers with phosphate buffers of 0.4, 0.6, 1.2, and 2.0 M for 2 h, and bands were located by exposure to iodine vapor or by spraying with ninhydrin. The low density fraction and the low density fraction of the granule each gave two subfractions, while the phosvitin–lipovitellin fraction yielded three components and the water-soluble fraction four components. The additional resolution apparently was due to differences in lipid and protein composition and structure, as well as to the content of protein-bound phosphorus. The described separations offer special advantages for the study of the lipid parts of the lipoprotein complexes.

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THE MACROMOLECULAR COMPOSITION OF HEN'S EGG YOLK AT SUCCESSIVE STAGES OF MATURATION

Canadian Journal of Biochemistry ◽

10.1139/o67-068 ◽

1967 ◽

Vol 45 (4) ◽

pp. 591-601 ◽

Cited By ~ 13

Author(s):

S. L. Mackenzie ◽

W. G. Martin

Keyword(s):

Soluble Fraction ◽

Early Period ◽

Egg Yolk ◽

Water Soluble ◽

Low Density ◽

Yolk Formation ◽

Water Soluble Fraction ◽

Density Fraction ◽

Hen’S Egg ◽

Macromolecular Composition

Yolk at different stages of its formation was separated into its major macromolecular fractions, namely, granules, low-density fraction (LDF), and water-soluble fraction (WSF), and the components of these fractions were examined by ultracentrifugal, electrophoretic, and chromatographic methods. Total yolk solids and the amounts of the several fractions all increased exponentially during yolk formation but at differential rates for different fractions. The proportion of LDF increased rapidly to a maximum (76% of total solids) for yolks weighing 2–5 g, and then declined. Both the WSF and granule fractions decreased in proportion during the early period of yolk formation and then increased slightly as yolk neared maturity. Of the WSF components, the proportions of α-livetin (serum albumin) and β-livetin increased somewhat and γ-livetin (serum γ-globulin) decreased slightly, during yolk maturation. The major granule subfraction, PvLv, showed an increased proportion of phosvitin and α-lipovitellin relative to β-lipovitellin during yolk formation. This increase in the proportions of the phosphorus-rich proteins was not paralleled by a corresponding increase in PvLv phosphorus, which suggests that other phenomena may be involved.

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FRACTIONATION OF LIVETIN AND THE MOLECULAR WEIGHTS OF THE α- AND β-COMPONENTS

Canadian Journal of Biochemistry and Physiology ◽

10.1139/o57-031 ◽

1957 ◽

Vol 35 (4) ◽

pp. 241-250 ◽

Cited By ~ 23

Author(s):

W. G. Martin ◽

J. E. Vandegaer ◽

W. H. Cook

Keyword(s):

Light Scattering ◽

Soluble Protein ◽

Soluble Fraction ◽

Egg Yolk ◽

Water Soluble ◽

Water Soluble Fraction ◽

Molecular Weights ◽

Water Soluble Protein ◽

Hen Egg Yolk ◽

Hen Egg

Livetin, the major water-soluble protein of hen egg yolk, was found to contain three major components having mobilities of −6.3, −3.8, and −2.1 cm.2 sec.−1 volt−1 at pH 8, µ 0.1, and these have been designated α-, β-, and γ-livetin respectively. The α- and β-livetins were separated and purified electrophoretically after removal of γ-livetin by precipitation from 37% saturated ammonium sulphate or 20% isopropanol. The α-, β-, and mixed livetins resembled pseudoglobulins in solubility but γ-livetin was unstable and this loss of solubility has, so far, prevented its characterization. Molecular weights determined by light scattering, osmotic pressure, and Archibald sedimentation procedure yielded respectively: 8.7, 7.8, and 6.7 × 104 for α-livetin, and 4.8, 5.0, and4.5 × 104 for β-livetin. Under suitable conditions of sedimentation and electrophoresis, egg yolk has been shown to contain three components having the same behavior as the three livetins of the water-soluble fraction.

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Ultracentrifugal and electrophoretic analysis of the water-soluble fraction of chick embryo yolk

Development ◽

10.1242/dev.19.1.95 ◽

1968 ◽

Vol 19 (1) ◽

pp. 95-101

Author(s):

P. Carinci ◽

L. Manzoli-Guidotti

Keyword(s):

Soluble Fraction ◽

Relative Proportion ◽

Egg Yolk ◽

Electrophoretic Analysis ◽

Egg White ◽

Water Soluble ◽

Water Soluble Fraction ◽

Egg White Proteins ◽

Proportional Increase ◽

Quantitative Changes

Water-soluble proteins, mainly livetins (α-, β-, γ-), are present in hen egg yolk (Martin, Vandegaer & Cook, 1957). They represent 5% of fresh yolk solids (Saito, Martin & Cook, 1965). During the later stages of incubation the watersoluble proteins (water-soluble fraction, WSF) undergo a marked increase in relative proportion; after 15 days of incubation they form over 15% and at 18 days over 40% of yolk-residual solids (Saito et al. 1965). This proportional increase of the WSF is tentatively explained by the passage of egg-white proteins into yolk (Mclndoe, 1960; Saito et al. 1965). Indeed some egg-white proteins (ovalbumin, conalbumin and lysozyme) have been found in the yolk from 14 to 15 days of incubation (Saito & Martin, 1966; Carinci, Wegelin & Manzoli-Guidotti, 1966). At these stages ovalbumin is present in the yolk in such a great quantity that it is difficult to detect qualitative and quantitative changes of other proteins without resorting to further fractionations.

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Immunochemical analysis of the water-soluble fraction of the chick embryo yolk

Development ◽

10.1242/dev.24.1.13 ◽

1970 ◽

Vol 24 (1) ◽

pp. 13-20

Author(s):

C. E. Grossi ◽

P. Carinci ◽

L. Manzoli-Guidotti

Keyword(s):

Serum Proteins ◽

Soluble Fraction ◽

Egg Yolk ◽

Water Soluble ◽

Immunochemical Analysis ◽

Adult Chicken ◽

Water Soluble Fraction ◽

Chicken Serum ◽

Protein Components ◽

Immunochemical Techniques

By means of immunochemical techniques, the protein components of the water-soluble fraction (WSF) of the egg yolk have been examined in the unincubated egg and during incubation. Anti-ovalbumin and anti-total adult chicken serum antisera have been employed. Ovalbumin can be detected in the unincubated WSF as well as during incubation; its concentration seems to increase during incubation. In the WSF of the unincubated egg, six proteins immunologically related to adult serum proteins can be detected. They correspond to α-livetin, α1-globulin, β-livetin, ovotransferrin (conalbumin) and γ-livetin (two components). β-Livetin disappears after the 14th day of incubation while the other components can be demonstrated till hatching. The findings are discussed in relation to the data available in the literature. The findings are discussed in relation to the data available in the literature.

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