Disease relevance of FETUIN

• The endo-alpha-N-acetylgalactosaminidase from the culture medium of Streptomyces sp. OH-11242 (endo-GalNAc-ase-S) hydrolyzed the O-glycosidic linkage between GalNAc and Ser (Thr) in fetuin, liberating oligosaccharides [1].
• The purified lectin was specific for both T-antigen and N-acetyl-D-lactosamine, markers for various carcinomas, in addition to N-acetyl-D-galactosamine, asialofetuin and fetuin [2].
• The influence of cultivation medium on fetuin binding by Lactobacillus fermentum L 670 was also not significant while Lactobacillus casei subsp. pseudoplantarum L.c. bound fetuin significantly better (P < 0.01) after growth on Rogosa agar [3].

High impact information on FETUIN

• In all cases, the binding was inhibited by glycoproteins such as fetuin and thyroglobulin, by a glycopeptide isolated from fetuin, and by some bacterial lipopolysaccharides [4].
• Infection of swine testicular cells with group C AmC-1 virus was also prevented by glycophorin A, fetuin, and neuraminidase treatment, suggesting that sialic acid constitutes an essential part of the cell receptor [5].
• Neuraminidase treatment of fresh human erythrocytes or blocking with glycophorin A or fetuin prevented hemagglutination [5].
• The acrylamide copolymers containing approximately 40 units of Gal beta 1,3GlcNAc beta-, Gal beta 1,3(6-sulfo)GlcNAc beta-, or fetuin triantennary asialo or bovine IgG diantennary glycopeptides were respectively 5.9-, 5.4-, 0.7-, and 0.1-fold as active [6].
• Although the proportion of Con A-reactive variants of fetuin and AT changes during fetal development, the predominant microform was always that with intermediate affinity against Con A [7].

Biological context of FETUIN

• Comparison of the deduced amino acid sequences of sheep and pig fetuin showed an extensive sequence identity between them (75%) and with other proteins of the mammalian fetuin family, i.e. human alpha 2-HS glycoprotein, and bovine and rat fetuins [8].
• An inhibitory effect of fetuin on porcine and caprine sperm motility was also observed [9].
• Fetuin is present early in gestation in a few cells bordering the ventricle [10].
• In competitive binding assays using b-ZP3 (0.1 microgram/ml) as probe, heat-solubilized zonae and ZP3 were effective competitors, whereas the nonzona molecules fetuin and fucoidin were not [11].

Anatomical context of FETUIN

• Taking the similarities of human and monkey or pig stomachs into consideration, these results suggest that the primary target cell of H. pylori in colonization in human stomachs is the antral epithelial cell and that the putative adhesin involved in adhesion has affinity for fetuin [12].
• HoloRBP, but not fetuin or apoRBP, decreased (p < 0.05) TBARS production in all but Day 30 endometrial membranes [13].
• At postnatal day 28 no alpha 2HS-positive cells or fibres could be found in the neocortex. alpha 2HS has been reported to be very closely related to fetuin which is a fetal plasma protein found in cells of the developing cortex in the sheep and the pig [14].
• In extracts from fetuses up to 32 days of gestation, the major serum proteins were fetuin, alpha-fetoprotein and alpha 1-antitrypsin, but albumin was not detected [15].
• PDC-109 competed effectively with zona pellucida glycoproteins for AWN binding, whereas fetuin was a poor competitor [16].

Associations of FETUIN with chemical compounds

• The enzyme catalyzed the formation of beta1 leads to 4 bonds between galactose and free terminal N-acetylglucosaminyl residues of soluble preparations of porcine IgG immunoglobulin heavy chain, fetuin, ovalbumin, and ovomucoid [17].
• The Km of the purified enzyme was 2.9 x 10(-5) M for fetuin, 5.4 x 10(-5) M for ovalbumin, 2.0 x 10(-5) M for IgG immlnoglobulin heavy chain, and 2.2 x 10(-5) M for UDP-galactose [17].
• Antibodies made to synthetic peptides of fetuin were used to identify the wallaby glycoprotein [18].
• These effects were inhibited with 100 mM GalNAc, GlcNAc, or Neu5Ac and 0.2 microM of sialylated submaxillary gland mucin and fetuin [19].
• Attachment was inhibited by N-acetylneuraminic acid, D-glucuronic acid, and fetuin [20].

Other interactions of FETUIN

• The concentration of all proteins rose with age until 40-50 days of gestation; and then the serum concentration of alpha-fetoprotein (2.9 mg ml-1), alpha 1-antitrypsin (4.4 mg ml-1) and transferrin (2.6 mg ml-1) fell progressively to about 1 mg ml-1 at birth, whereas those of fetuin, albumin and alpha 1-acid glycoprotein increased [15].
• In our experiments the enzyme did not hydrolyse the (alpha - 2.6) or (alpha - 2.8) bonds of submaxillary pig mucin and colominic acid, respectively, but it hydrolysed such substrates as fetuin, ovomucin, orosomucoid and horse serum glycoproteins [21].
• Transferrin and fetuin were the major proteins in amniotic fluid during the second trimester of gestation and together with AFP and albumin accounted for the majority of the total protein in amniotic, but not allantoic fluid [22].

Analytical, diagnostic and therapeutic context of FETUIN

• The inhibitory activity resided in the second peak when fetuin was separated by isoelectric focusing [9].
• The structure of the pyridylaminated O-linked oligosaccharides from fetuin has been determined by reverse-phase HPLC and 600-MHz 1H-NMR spectroscopy [1].
• Immobilization of trypsin resulted in digestions comparable with standard solution digestions using fetuin as a model substrate [23].
• The distributions of 4 plasma proteins (fetuin, transferrin, alpha-fetoprotein and albumin) have been studied by means of immunocytochemistry in the forebrain of the pig from 20 to 109 days of gestation, term being at 114 days [10].
• A radioimmunoassay for fetuin is described [24].

References