Biomedical subjects
Publications and source records attributed to J R Clamp.
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1. The slime produced by eight strains of Pseudomonas aeruginosa on a number of different media was demonstrated to be qualitatively the same. Small quantitative differences may be occasioned by differences in the extraction procedure, the growth medium or the strain of organism used. 2. The slime was shown to be predominantly polysaccharide with some nucleic acid material and a small amount of protein. 3. The hydrolysed polysaccharide fraction consists mainly of glucose with smaller amounts of mannose. This accounts for some 50-60% of the total slime. In addition, there is some 5% of hyaluronic acid. The nucleic acid material represents approx. 20% of the total weight, and is composed of both RNA and DNA. 4. Minor components are protein, rhamnose and glucosamine, the protein being less than 5% of the total. 5. Hyaluronic acid is produced in greater quantities from nutrient broth than from chemically defined media, and is more firmly attached to the cells than the other components.
For a monomeric molecular weight of 180000 three type K macroglobulins (IgM) contained 6-deoxygalactose, mannose, galactose, 2-acetamido-2-deoxyglucose and N-acetylneuraminic acid in the molar proportions 5:38:11:27:7 for Row IgM, 5:31:9:21:7 for Sha IgM, and 5:29:11:26:8 for Tya IgM. The first two proteins were euglobulins whereas Tya IgM was a pseudoglobulin, and therefore the total content of carbohydrate does not appear to be related to the physicochemical properties of the proteins. The three proteins appeared to contain different numbers of oligosaccharide units, Row IgM having about ten units/monomer, and Sha IgM and Tya IgM about eight each. All three proteins had two types of oligosaccharide unit, which by analogy with an immunoglobulin A myeloma globulin were called Type 2 and Type 3 respectively. The Type 2 units had molecular weights equal to or greater than 2000 and contained 1 residue of 6-deoxygalactose, 3-4 of mannose, 1-2 of galactose, 3-4 of 2-acetamido-2-deoxyglucose and 0-2 of N-acetylneuraminic acid. The Type 3 units had molecular weights of less than 2000 and contained 0-1 residue of 6-deoxygalactose, 3-6 of mannose, 0-1 of galactose, 1-3 of 2-acetamido-2-deoxyglucose and no N-acetylneuraminic acid. Glycopeptides corresponding to the two types of unit varied in their aspartic acid content in that most of the Type 3 glycopeptides possessed only 1 residue of aspartic acid whereas most of the Type 2 glycopeptides had an average content greater than 1 residue.
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The carbohydrate content of an A myeloma globulin was investigated. The carbohydrate content was found to be unchanged when the protein was isolated from the patient over a period of 18 months. The various polymeric forms of the protein contained similar proportions of carbohydrate. The A myeloma globulin contained approx. 2 residues of 6-deoxy-l-galactose (l-fucose), 14-15 of d-mannose, 12-13 of d-galactose, 12-13 of 2-acetamido-2-deoxy-d-glucose (N-acetyl-d-glucosamine), 6 of 2-acetamido-2-deoxy-d-galactose (N-acetyl-d-galactosamine) and 5 of N-acetylneuraminic acid (sialic acid), and these were distributed between six oligosaccharide units all of which were present on the heavy polypeptide chains. The oligosaccharide units showed two kinds of heterogeneity, which have been termed central and peripheral. Central heterogeneity was shown by the presence of three completely different core units, which had the following compositions: (1) 3 residues of d-galactose and 3 of 2-acetamido-2-deoxy-d-galactose, joined to protein by an O-glycosidic linkage between acetamidohexose and serine; (2) 3 residues of d-mannose, 2 of d-galactose and 3 of 2-acetamido-2-deoxy-d-glucose, joined to protein by an N-glycosidic linkage between acetamidohexose and aspartic acid; (3) 4 residues of d-mannose and 3 of 2-acetamido-2-deoxy-d-glucose with a linkage similar to that in (2). The core oligosaccharide units showed peripheral heterogeneity in the attachment of 6-deoxy-l-galactose, 2-acetamido-2-deoxy-d-glucose and N-acetylneuraminic acid. Tentative structures are proposed for these various types of oligosaccharide unit. Glycopeptides were isolated in which the sialic acid content exceeded that of d-galactose. Explanations are given for the electrophoretic mobility and staining characteristics of the various glycopeptides.
The urinary protein excreted in heavy-chain disease was separated by ion-exchange chromatography into two broad fractions designated Cra-1 and Cra-2. For a dimeric molecular weight of approx. 51000, Cra-1 contained 3-4 residues of 6-deoxy-l-galactose (l-fucose), 10 of d-mannose, 5-6 of d-galactose, 12 of 2-acetamido-2-deoxy-d-glucose (N-acetyl-d-glucosamine) and 4-5 of N-acetylneuraminic acid (sialic acid), whereas the corresponding values for Cra-2 were 2, 10, 7, 12 and 7. Cra-2 contained in addition 1 residue of 2-acetamido-2-deoxy-d-galactose (N-acetyl-d-galactosamine). Cra-1 contained an average of four oligosaccharide units, two of which contained 1 residue of 6-deoxy-l-galactose, 3 of d-mannose, 1 of d-galactose and 3 of 2-acetamido-2-deoxy-d-glucose, whereas the other two units contained the same proportions of 6-deoxy-l-galactose, d-mannose and 2-acetamido-2-deoxy-d-glucose but 2 residues of d-galactose and 2 of N-acetylneuraminic acid. Cra-2 also contained an average of four oligosaccharide units, but the range of glycopeptides was much wider, containing 0-1 residue of 6-deoxy-l-galactose, 2-3 of d-mannose, 2-3 of d-galactose, 2-3 of 2-acetamido-2-deoxy-d-glucose and 1-3 of N-acetylneuraminic acid. Possible reasons for this heterogeneity are discussed. Glycopeptides were also isolated from Cra-2 that contained 1 residue of d-mannose, 2 of d-galactose, 1 of 2-acetamido-2-deoxy-d-galactose and 0-3 of N-acetylneuraminic acid.
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The oligosaccharide units of a type K and a type L IgA immunoglobulin have been examined. The two proteins differed in their content of 6-deoxy-l-galactose and N-acetylneuraminic acid, and in the d-mannose/d-galactose ratio. With glycopeptides prepared from the type K protein, specific glycosidases liberated the N-acetylneuraminic acid and 7-8 residues of 2-acetamido-2-deoxy-d-glucose, and mild acid hydrolysis released most of the 6-deoxy-l-galactose. The type K immunoglobulin appeared to contain 3 oligosaccharide units, whereas the type L protein probably contained 3 or more units.