-
Journal of Embryology and Experimental... Dec 1985A lectin with an affinity for certain sulphated polysaccharides, such as fucoidin and dextran sulphate, has been isolated from the vitelline membrane of hens' eggs and...
A lectin with an affinity for certain sulphated polysaccharides, such as fucoidin and dextran sulphate, has been isolated from the vitelline membrane of hens' eggs and purified to homogeneity as assessed by two-dimensional gel electrophoresis. Polyclonal and monoclonal antibodies have been raised to the lectin and used in indirect immunofluorescence microscopy to localize the agglutinin in the outer layer of the vitelline membrane, where the lectin persists prior to the breakdown of the vitelline membrane. The quantity of lectin extracted from the two layers of the membrane, which have been separated by the method of Bellairs, Harkness & Harkness (1963), correlated well with the results of immunofluorescence microscopy. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis of the two layers of the membrane indicates that each layer has a distinctive polypeptide composition, the outer layer containing in particular lysozyme and avidin. The evidence obtained in this study indicates that the lectin is not involved in adhesion of the blastoderm to the vitelline membrane; neither is it involved in the expression of the blastoderm nor in maintaining the strength of the membrane. The possible roles in promoting transport of solutes across the membrane as well as providing bactericidal properties to the egg are discussed.
Topics: Animals; Chickens; Dextran Sulfate; Dextrans; Electrophoresis, Polyacrylamide Gel; Fluorescent Antibody Technique; Hemagglutination; Immunodiffusion; Isoelectric Focusing; Lectins; Microscopy, Fluorescence; Ovum; Peptides; Polysaccharides; Vitelline Membrane
PubMed: 2422312
DOI: No ID Found -
The Biochemical Journal Aug 1992The outer layer of the vitelline membrane from hen egg yolk consists of ovomucin, vitelline membrane outer layer protein I (VMOI) and lysozyme. Here we report the...
The outer layer of the vitelline membrane from hen egg yolk consists of ovomucin, vitelline membrane outer layer protein I (VMOI) and lysozyme. Here we report the occurrence of a further basic protein (pI 11.5) in the outer layer, which was designated as vitelline membrane outer layer protein II (VMOII). It was dissociated from the outer layer in a 10% (w/v) NaCl solution and purified to homogeneity by ion-exchange chromatography. VMOII is a simple protein with a molecular mass of 6000 Da, as determined by sedimentation equilibrium analysis. The amino acid composition of VMOII was characterized by the absence of Met and high contents of cystine (half) (14%) and basic amino acids (6% Arg, 6% Lys and 3% His). Analysis of carboxymethylated VMOII indicated that all cysteine residues were involved in disulphide bonding, which appears to facilitate the binding of SDS to the protein. Sequence comparison of the N-terminal 20 residues revealed no identity with other known proteins. VMOII contained a small amount of alpha-helix and was quite resistant to heat denaturation.
Topics: Amino Acid Sequence; Amino Acids; Animals; Chickens; Chromatography, Gel; Chromatography, Ion Exchange; Circular Dichroism; Egg Proteins; Electrophoresis, Polyacrylamide Gel; Female; Molecular Sequence Data; Molecular Weight; Peptide Mapping; Protein Conformation; Vitelline Membrane
PubMed: 1520265
DOI: 10.1042/bj2860017 -
The EMBO Journal Mar 1994The crystal structure of vitelline membrane outer layer protein I (VMO-I), which is isolated from the vitelline membrane outer layer of hen's eggs, has been determined... (Comparative Study)
Comparative Study
The crystal structure of vitelline membrane outer layer protein I (VMO-I), which is isolated from the vitelline membrane outer layer of hen's eggs, has been determined by the multiple isomorphous replacement method and refined to an R-factor of 18.8% at 2.2 A resolution. The main chain folds into an unusual structure that consists of three beta-sheets forming Greek key motifs, which are related by an internal pseudo three-fold symmetry. The internal portion surrounded by these three beta-sheets is filled with hydrophobic side chains. This conformational feature coincides with three internal repeats in the sequence. Although a similar fold exists in the second domain of delta-endotoxin, there are significant structural differences between the two proteins, with the three-fold symmetry being most regular in VMO-I.
Topics: Amino Acid Sequence; Animals; Chickens; Circular Dichroism; Crystallography, X-Ray; Egg Proteins; Female; Models, Molecular; Molecular Sequence Data; Protein Folding; Protein Structure, Secondary; Vitelline Membrane
PubMed: 8131734
DOI: 10.1002/j.1460-2075.1994.tb06348.x -
Journal of Molecular Biology Jan 1994The vitelline membrane outer layer protein I (VMO-I), which is isolated from the vitelline membrane outer layer of hen's eggs, has been crystallized from an acetate...
The vitelline membrane outer layer protein I (VMO-I), which is isolated from the vitelline membrane outer layer of hen's eggs, has been crystallized from an acetate buffer solution by the hanging-drop method. The crystals belong to the orthorhombic space group P2(1)2(1)2(1), with unit cell dimensions a = 62.42 A, b = 110.52 A, c = 44.15 A. There are two molecules (M(r) = 18,000) per asymmetric unit. The crystals diffract to at least 2.2 A Bragg spacings.
Topics: Animals; Chickens; Crystallization; Crystallography, X-Ray; Egg Proteins; Membrane Proteins; Vitelline Membrane
PubMed: 8289303
DOI: 10.1006/jmbi.1994.1036 -
The International Journal of... 1986Salt solutions and charged detergents are efficient solubilizing agents for ovovitelline membrane lysozyme. Reassociation experiments with chemically modified lysozymes...
Salt solutions and charged detergents are efficient solubilizing agents for ovovitelline membrane lysozyme. Reassociation experiments with chemically modified lysozymes indicate that positively charged amino acid residues of lysozyme (the epsilon-amino group of lysine and the guanidino group of arginine) are involved in the interaction with other proteins of the vitelline membrane. Exogenous proteins are adsorbed to lysozyme-free vitelline membranes, only if they have a high pI, comparable to that of lysozyme. It is concluded that the lysozyme-ovovitelline membrane interaction is predominantly ionic. An ovomucin-lysozyme complex is postulated as the major component of the outer layer of the membrane.
Topics: Animals; Chickens; Female; Hydrogen-Ion Concentration; Kinetics; Muramidase; Proteins; Vitelline Membrane
PubMed: 3743871
DOI: 10.1016/0020-711x(86)90292-2 -
The Journal of Biological Chemistry Apr 1993The neurohormone serotonin (5-hydroxytryptamine, 5HT) triggers meiosis reinitiation in prophase-arrested oocytes of Spisula solidissima. The original pharmacological...
Meiosis reinitiation in surf clam oocytes is mediated via a 5-hydroxytryptamine5 serotonin membrane receptor and a vitelline envelope-associated high affinity binding site.
The neurohormone serotonin (5-hydroxytryptamine, 5HT) triggers meiosis reinitiation in prophase-arrested oocytes of Spisula solidissima. The original pharmacological profile of this response prompted us to examine whether it involved a novel type of 5HT receptor. In order to characterize these putative receptors, we performed [3H]5HT binding assays. Given the complexity of oocyte surface architecture, [3H]5HT-specific binding was measured in both plasma membrane and vitelline envelope fractions. Our data reveal the existence of a single class of 5HT-specific binding sites in each fraction. These binding sites appear distinct by their kinetic properties: 1) plasma membrane binding sites are of lower affinity but are more numerous than vitelline envelope sites; 2) [3H]5HT binding is more rapid in membrane fraction. The pharmacological profiles of both binding sites were defined in competition experiments by using sixteen 5HT-related and unrelated compounds. Both membrane and vitelline envelope sites displayed novel profiles. However, only the pharmacological profile determined for the plasma membrane sites corresponds to that observed for 5HT-induced meiosis reinitiation. These new 5HT5 binding sites are therefore the physiological receptors that mediate the effects of 5HT in Spisula oocytes. The putative role of vitelline envelope sites is discussed.
Topics: Adenosine Triphosphatases; Animals; Bivalvia; Cell Membrane; Female; Kinetics; Meiosis; Microscopy, Electron; Oocytes; Receptors, Serotonin; Serotonin; Serotonin Antagonists; Serotonin Receptor Agonists; Signal Transduction; Sodium-Potassium-Exchanging ATPase; Vitelline Membrane
PubMed: 8385130
DOI: No ID Found -
Developmental Biology Dec 1988Two Drosophila vitelline membrane (VM) genes located at polytene band positions 26A and 34C have been characterized at the nucleotide level. Sequence comparison of the...
Two Drosophila vitelline membrane (VM) genes located at polytene band positions 26A and 34C have been characterized at the nucleotide level. Sequence comparison of the two genes VM26A.1 and VM34C.1 has revealed a similar 114 base pair region centrally located in the coding regions of both genes. The conserved region has a 91% homology at the nucleic acid level and a 100% conservation at the amino acid level. This suggests a common evolutionary origin for these VM genes and indicates that a strong selective pressure exists to maintain a specific polypeptide sequence in a domain of the proteins.
Topics: Animals; Base Sequence; Drosophila melanogaster; Membrane Proteins; Molecular Sequence Data; Repetitive Sequences, Nucleic Acid; Vitelline Membrane
PubMed: 3143615
DOI: 10.1016/0012-1606(88)90367-3 -
The International Journal of... 1986Lysozyme accounts for 37% of the proteins of the hen's egg vitelline membrane. It can be extracted by salt solutions and purified by gel filtration on Sephadex G-50....
Lysozyme accounts for 37% of the proteins of the hen's egg vitelline membrane. It can be extracted by salt solutions and purified by gel filtration on Sephadex G-50. There are no differences between the chemical and enzymic properties of egg white and vitelline membrane lysozymes. Vitelline membranes of ovarian eggs do not contain lysozyme. It is thus concluded that lysozyme is localized in the outer layer. Vitelline membranes from fertilized and unfertilized eggs contain the same amount of lysozyme; its percentage decreases after two days of incubation.
Topics: Amino Acids; Animals; Cell Fractionation; Chick Embryo; Chickens; Female; Kinetics; Muramidase; Oocytes; Solubility; Vitelline Membrane
PubMed: 3743870
DOI: 10.1016/0020-711x(86)90291-0 -
Poultry Science Mar 2018In this study, we analyzed selected morphological traits of eggs, as well as structure, strength, and protein composition of the vitelline membrane (VM) of ostrich, emu,... (Comparative Study)
Comparative Study
In this study, we analyzed selected morphological traits of eggs, as well as structure, strength, and protein composition of the vitelline membrane (VM) of ostrich, emu, and greater rhea eggs. Ninety eggs (30 for species) were analyzed for the following parameters: egg weight, yolk weight, yolk ratio, and yolk index. In addition, pH value, water activity, consistency index, and flow behavior index were determined. The strength of VM was measured using the TA.HDPlus Texture Analyzer. Micrograph images were taken via a scanning electron microscope. Polyacrylamide gel electrophoresis was conducted under denaturing conditions. Ostrich eggs were characterized by the highest egg and yolk weight compared with those of emu and greater rhea eggs, whereas emu eggs had the highest yolk ratio compared with those of ostrich and greater rhea eggs (P > 0.05). Yolk content differed among the species in terms of water activity; it was found to be higher in emu eggs than in ostrich and greater rhea eggs (P > 0.05). Based on flow curves, yolks of the ratites were classified as pseudoplastic non-Newtonian fluids. The consistency index was significantly higher in yolks of ostrich and emu than that of greater rhea eggs, whereas the VM of yolks of greater rhea eggs was the most resistant (had the highest breaking force = 26.4 g). All species differed significantly regarding the structure of VM, the outer layer (OL) in particular, which was found to constitute fibers of various thicknesses that were differently arranged. Fibers of the OL of the VM of emu, whose fibers were the least differentiated but formed the most compact network, were the most diverse in characterization. An electropherogram of the VM of ostrich revealed 11 primary protein bands: 6 for the OL and 5 for the inner layer (IL), that of emu revealed 9 bands: 5 for the OL and 4 for the IL, and that of greater rhea revealed 10 bands: 6 for the OL and 4 for the IL.
Topics: Animals; Dromaiidae; Egg Yolk; Ovum; Rheiformes; Struthioniformes; Vitelline Membrane
PubMed: 29253213
DOI: 10.3382/ps/pex356 -
Journal of Innate Immunity 2019The integrated innate immune features of the calcareous egg and its contents are a critical underpinning of the remarkable evolutionary success of the Aves clade.... (Review)
Review
Dynamics of Structural Barriers and Innate Immune Components during Incubation of the Avian Egg: Critical Interplay between Autonomous Embryonic Development and Maternal Anticipation.
The integrated innate immune features of the calcareous egg and its contents are a critical underpinning of the remarkable evolutionary success of the Aves clade. Beginning at the time of laying, the initial protective structures of the egg, i.e., the biomineralized eggshell, egg-white antimicrobial peptides, and vitelline membrane, are rapidly and dramatically altered during embryonic development. The embryo-generated extra-embryonic tissues (chorioallantoic/amniotic membranes, yolk sac, and associated chambers) are all critical to counteract degradation of primary egg defenses during development. With a focus on the chick embryo (Gallus gallus domesticus), this review describes the progressive transformation of egg innate immunity by embryo-generated structures and mechanisms over the 21-day course of egg incubation, and also discusses the critical interplay between autonomous development and maternal anticipation.
Topics: Animals; Antimicrobial Cationic Peptides; Chick Embryo; Chickens; Egg Shell; Embryonic Development; Female; Immunity, Innate; Maternal-Fetal Exchange; Ovum; Pregnancy; Vitelline Membrane
PubMed: 30391943
DOI: 10.1159/000493719