William Niedermeier

Gas chromatography of neutral and amino sugars in glycoproteins

Abstract A gas chromatographic method for determining the neutral and amino sugars commonly found in glycoproteins of animal origin is described. Following mild acid hydrolysis, the solution is neutralized with Dowex 1 HCO3−, and the sugars are reduced to alditols in the cold with sodium borohydride. The solution is lyophilized, and the alditols are acetylated with acetic anhydride in pyridine. Monosaccharides can be determined on as little as 1 mg of a glycoprotein which contains 6% total carbohydrate.

Trace metal composition of synovial fluid and blood serum of patients with rheumatoid arthritis

Abstract Fifty specimens of synovial fluid from patients with rheumatoid arthritis and an equal number of specimens from cadavers who died with no evidence of connective tissue disease, were analyzed by emission spectrometry for 14 different trace metals. One hundred and five specimens of blood serum from patients with rheumatoid arthritis, and an equal number of specimens from normal volunteers were similarly analyzed. In blood serum from patients with rheumatoid arthritis, the mean concentrations of copper, barium, cesium, manganese, tin and molybdenum were high; iron, zinc and lead were low; and aluminium, nickel, strontium, chromium and cadmium were normal. In synovial fluid from patients with rheumatoid arthritis, the mean concentrations of copper, iron and zinc were high; aluminum, barium, tin, strontium and cadmium were low; and manganese, nickel, cesium, chromium, lead and molybdenum were normal.

Chemical studies on Clq; A modulator of immunoglobulin biology

Summary Complete amino acid analyses of purified Clq from human serum indicate that this glycoprotein has an unusual composition for a serum protein, which includes hydroxyproline, hydroxylysine and high levels of glycine. A majority of the hydroxylysine residues are resistant to periodate oxidation; presumably they are protected by linkages to carbohydrate groups. In addition the total carbohydrate content is 7.7%, consisting primarily of glucose and galactose in equimolar amounts. Smaller quantities of sialic acid, fucose, mannose, galactosamine and glucosamine were also found. Thus, the data indicate that Clq has a structural similarity to collagen and collagen-like proteins.

Gas chromatographic analysis of hexosamines in glycoproteins

Abstract A gas chromatographic method for the analysis of hexosamines in glycoproteins was described which uses the alditol acetate derivatives of the sugars. A polyamide (Poly A 103) liquid phase was used which effectively separates glucosamine, galactosamine, and mannosamine from each other. Mannosamine served as internal standard to facilitate accurate quantitation of glucosamine and galactosamine.

The differences in carbohydrate composition between the subclasses of IgA immunoglobulins.

Abstract Statistical analyses of the carbohydrate compositions of eleven IgA1 and six IgA2 meyloma proteins revealed that in addition to the known difference in the content of galactosamine, which is present only in proteins of IgA1 subclass, there are further quantitative differences in the carbohydrate composition of both subclasses. IgA2 immunoglobulins have significantly higher total carbohydrate content due to higher concentrations of fucose, mannose and glucosamine. No differences between the subclasses were found in the content of galactose and sialic acid. Certain relationships between monosaccharides in proteins of individual subclasses were established: in IgA1 the sialic acid content was found to be inversely correlated with fucose, in IgA2 a positive correlation was observed between galactose and sialic acid.

Emission Spectrometric Determination of Trace Elements in Biological Fluids

An emission spectrometric method of analysis is described, in which trace quantities of copper, iron, aluminum, barium, manganese, nickel, cesium, tin, strontium, chromium, zinc, lead, molybdenum, and cadmium were determined in blood serum. The sample preparation, starting with 2.0 ml of blood serum, is discussed in detail. The source of excitation was a 10 A dc arc. Quantitation was achieved with a direct reading emission spectrometer. The metal concentration, in micrograms per 100 ml of blood serum, was calculated from the experimental data by means of a computer.

Microdetermination of monosaccharides in glycoproteins by gas-liquid chromatography.

Abstract In a newly developed method for determining picomolar quantities of monosaccharides in glycoproteins, the methyl glycosides released by methanolysis of glycoproteins are separated as trifluoroacetates by gas-liquid chromatography and are detected with an electron capture detector. The application of the method has been demonstrated for the analysis of the carbohydrate moiety of secretory component isolated from human colostral immunoglobulin A.

The carbohydrate composition of human myeloma IgA

Abstract The composition and distribution of carbohydrates in the polypeptide chains of seven human IgA myeloma proteins were studied. It was found that 89–96 per cent of the carbohydrate was associated with the heavy (H) chains. Six of the immunoglobulins had similar carbohydrate compositions. Their H chains contained 0.3–0.6 residues of fucose, 4–5 of mannose, 5–6 of galactose, 4–5 of glucosamine, 2 of galactosamine, and 3–4 of sialic acid. One immunoglobulin lacked galactosamine, but had a higher carbohydrate content, and the relative proportions of the various monosaccharides present were different from those observed in the six immunoglobulins that contained this amino sugar. H chains of this IgA contained 3 residues of fucose, 13 of mannose, 3 of galactose, 12 of glucosamine and 1 of sialic acid. The preparations of light (L) chain contained small quantities of the same monosaccharides found in H chain with two exceptions; galactosamine was missing from all the L chain preparations and fucose was not found in two of them. The L chain preparations from dimeric immunoglobulins contained J chains, which were shown to contribute more than 50 per cent of the carbohydrates present in one of these preparations.

Sensitive gas chromatographic determination of the monosaccharide composition of glycoproteins using electron capture detection

Abstract A gas chromatographic procedure using electron capture detection has been developed for the monosaccharide analysis fo submicrogram quantites of glycoproteins. Methanolysis of the glycorproteis and subsequent trifluoroacetylation of the resultant methyl glycosides using N-mehylbis(trifluoacetamide) is carried out in a single capillary tube. The carbohydrate composition of 0.1 μg of several glycoproteins has been quantitativly determined by this method.

The carbohydrate composition of J chain from human serum and secretory IgA

Abstract J chains prepared from human serum IgA and human secretory IgA both contained 7.6% total carbohydrate. The monosaccharide compositions were similar and on the basis of a molecular weight of 26 000 each J chain contained 1 mole fucose, 3 moles mannose, 2 moles galactose, 3–4 moles glucosamine and 1 mole of sialic acid.