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Biomedical subjects

F Egami

Publications and source records attributed to F Egami.

At least 73 records · Page 4Linked to original sources
PubMed1971

Isolation and fractionation of glycopeptides from porcine thyroglobulin.

1. Glycopeptides were isolated by gel filtration on Sephadex G-25 and Sephadex G-50 from a Pronase digest of porcine thyroglobulin. 2. Isolated glycopeptides were separated into five main fractions on a column of DEAE-Sephadex A-25. Of these fractions I to III were further purified by SE-Sephadex C-25 or DEAE-Sephadex A-25 column chromatography. Several of the purified glycopeptides were homogeneous on paper electrophoresis. 3. Based on the chemical composition and molecular weight of the fractionated glycopeptides, two distinct types of heterosaccharide chain were demonstrated. 4. One type of the heterosaccharide unit consisted of four to eight residues of mannose and two residues of glucosamine and had a molecular weight of 1000-1700. The other type of unit contained sialic acid, fucose and galactose in addition to mannose and glucosamine and had a molecular weight of about 3600. 5. Mild alkaline treatment of the glycopeptide did not result in the destruction of threonine and serine. 2-Acetamido-1-N-(4-l-aspartyl)-2-deoxy-beta-d-glucopyranosylamine was isolated from partial acid hydrolysates.

Animals↗
PubMed1971

The structure of a glycopeptide purified from porcine thyroblobulin.

1. The structure of a purified glycopeptide isolated from porcine thyroglobulin was studied by sequential hydrolysis with specific glycosidases, by periodate oxidation and by treatment with galactose oxidase. 2. Sequential hydrolysis with several combinations of neuraminidase, alpha-l-fucosidase, beta-d-galactosidase, beta-N-acetyl-d-glucosaminidase and alpha-d-mannosidase presented the evidence for the following structure. 3. The monosaccharide sequence of the peripheral moiety of the heteropolysaccharide chain was sialic acid-->galactose-->N-acetylglucosamine. Some of the galactose residues were non-reducing end-groups with the sequence galactose-->N-acetylglucosamine. 4. After removal of the peripheral moiety composed of sialic acid, fucose, galactose and N-acetylglucosamine, alpha-mannosidase released 1.4mol of mannose/mol of glycopeptide, indicating that two of the three mannose residues were located between peripheral N-acetylglucosamine and internal N-acetylglucosamine or mannose. 5. Periodate oxidation and sodium borohydride reduction confirmed the results obtained by enzymic degradation and gave information concerning the position of substitution. 6. Based on the results obtained by enzymic hydrolysis and periodate oxidation together with the treatment with galactose oxidase, a structure is proposed for the glycopeptide.

Alcohol Oxidoreductases↗
PubMed1970

Enzymic degradation of keratosulphates.

1. A multienzyme system capable of degrading keratosulphates to yield galactose, N-acetylglucosamine and sulphate was found in the liver extract of a marine gastropod, Charonia lampas. 2. During the degradation, neither oligosaccharides nor sulphated sugars were produced. 3. It is suggested that the degradation could be attributed to the concerted action of beta-galactosidase, beta-N-acetylglucosaminidase and a sulphatase (sulphohydrolase), tentatively designated keratosulphatase. 4. Two forms of keratosulphatase (I and II) were separated by DEAE-Sephadex column chromatography. Both forms could release all the sulphate from keratosulphates and neither appeared to be identical with glycosulphatase or chondrosulphatase, both of which are also present in Charonia lampas. 5. beta-Galactosidase and beta-N-acetylglucosaminidase could degrade keratopolysulphate to a greater extent in the presence of keratosulphatase than in its absence. 6. It is suggested that keratosulphate was first desulphated by the action of keratosulphatase, and the desulphated polymer was then degraded to galactose and N-acetylglucosamine by the action of beta-galactosidase and beta-N-acetylglucosaminidase. 7. beta-Galactosidase alone released a small amount of galactose from shark cartilage keratopolysulphate, but beta-N-acetylglucosaminidase alone did not release N-acetylglucosamine. This indicates that unsulphated galactose residues occupy all the non-reducing terminal positions in keratopolysulphate chains.

Animals↗