Tropomyosin, the Major Oyster Crassostrea gigas Allergen and its IgE-binding Epitopes

The major allergen ( Cra g 1) isolated from the oyster Crassostrea gigas was digested with lysylendopeptidase. Twenty-one peptide fragments were isolated from the digest by reverse-phase HPLC and some of them were sequenced. Cra g 1 was identified as tropomyosin. In competitive ELISA inhibition analyses of lysylendopeptidase fragments, a peptide (K21) showed maximum inhibition of the binding of IgE antibodies in sensitive human serum to Cra g 1. On further tryptic hydrolysis of K21, two peptides exhibited high inhibitory ability equivalent to K21. These results suggested that Cra g 1 had an IgE-binding epitope in the segment 92–105 (IQLLEEDMERSEER) which was dissimilar to those of the major allergen (tropomyosin) from the shrimp Penaeus indicus.     

Glass Formation Range, Acid Resistivity, and Surface Charge Density of ZnO-B2O3-SiO2 Passivation Glass Containing Al2O3

The glass formation range in the system ZnO-B₂O₃-SiO₂ increases when 5% Al₂O₃ is added and then decreases with further Al₂O₃ additions. The acid resistivity of the glass also increases when Al₂O₃ is added. An observed increase in negative charge with Al content until the system contains equal amounts of Al and Si (in forms of mole %) is explained by the formation of AlO₄⁻ tetrahedra which substitute in the SiO₄ network. Alkaline-earth oxides cause a positive charge which compensates for the negative charge formed by Al₂O₃. Antimony oxide and lanthanum oxide result in a negative charge in the glass. The formation of a negative or positive charge in the glass is thought to reflect the acidity or basicity of the glass, respectively.     

POLYSACCHARIDE 13140: A NEW THERMO-GELABLE POLYSACCHARIDE

Polysaccharide 13140, a curdlan-type polysaccharide produced from a culture filtrate of Alcaligenes faecalis var. myxogenes strain NTK-u, has the unique property of forming a gel on heating. This polysaccharide is composed of β-1,3 linked glucose residues. When heated, aqueous suspension of the polysaccharide forms an elastic gel which is thermally irreversible, heat stable and acid stable. The texture properties of the polysaccharide gel lie in between agar-agar gel and gelatin gel. Potential applications of the polysaccharide in food processing are quite diverse and promising because it can improve such properties as viscoelasticity, palatability, binding quality, water holding capacity, heat stability and compatibility