Biochimica et Biophysica Acta (BBA) - Specialized Section on Mucoproteins and Mucopolysaccharides最新文献

Soluble methylprednisolone, given to rabbits in a dose of 3 mg in 1 ml intramuscularly per day causes (1) an increase in the concentration of mucopolysaccharide uronic acid in the vitreous humor compared with concentrations in a saline-treated control group, and (2) an increase in the absolute amount of mucopolysaccharide glucosamine in the costal cartilage of the same animals with an accompanying increased concentration of neutral sugar as measured by the anthrone reaction.

On the basis of data obtained, it is postulated that adrenal corticosteroids produce both an increase of hyaluronate in the vitreous humor and an increase in keratosulfate in costal cartilage.

It is thought that the most likely explanation of these phenomena is that these steroid hormones in small doses, regardless of whether or not they inhibit both synthesis and breakdown, cause an overall inhibition of degradation of these glucosamine-containing substances.

A preparative method has been developed for the isolation of a fraction containing both glucosamine and aspartic acid by hydrolysis of the previously described polysaccharide-aspartic acid fraction from egg albumin.

It was confirmed, that the polysaccharide group is bound to the protein through a terminal glucosamine residue.

The quantitative composition and the chemical and physical properties of the fragment agree with the structure of a 2-acetamido-1-β (l-β-aspartamido)-1,2-deoxy-d-glucose.

This investigation involves an attempt to determine the chemical nature of the bacteriophage receptor site of Staphylococcus aureus. Cell walls of the propagating strain of phage 77 were isolated by sonic oscillation and density-gradient centrifugation. They were further disintegrated by sonic oscillation and fractionated. Fractions were tested for phage-inactivating ability and attachment of phage. Particles of approx. 200 mμ diameter were isolated which were capable of both inactivation and attachment.

Chemical analysis of these particles indicated no nucleic acid, protein or polysaccharide. The amino acids glycine, lysine, alanine and glutamic acid were found by paper chromatography. Muramic acid and N-acetylglucosamine were also found. These findings indicate that the phage receptor site of the Staphylococcus cell wall is a mucopeptide. Teichoic acid has not been implicated. Inactivating ability was destroyed by heat and trichloroacetic acid. It was enhanced by trypsin (EC 3.4.4.4.) and lysozyme (EC 3.2.1.17).

The absorption characteristics of complexes of hyaluronic acid and chondroitin sulfate C with toluidine blue were studied. From the physical requirements necessary to form the metachromatic complexes, suggestions have been made concerning the conformation of the two polysaccharides.

A glycoprotein containing 4.3% neutral sugar, 2.07% amino sugar and 0.4% sialic acid has been isolated from bovine vitreous body. It is electrophoretically homogeneous and has a mobility of −2.2·10⁻⁵ cm²/V sec, which places it among the γ-globulins. The sedimentation coefficient and diffusion constant indicate a molecular weight slightly lower than the generally accepted values for γ-globulins. Other examples of connective tissue proteins which resemble, but are not identical to, plasma proteins are discussed.

Microgram quantities of glycosaminoglycans can be quantitatively liberated from tissues, fractionated and determined by the following procedure: (1) Digestion of the tissue sample with papain (EC 3.4.4.10). (2) Precipitation of the glycosaminoglycans as their cetylpyridinium complexes on an inert support of powdered cellulose packed in a column. (3) Fractional elution of the complexes from the column with salt solutions of increasing concentration. (4) Estimation of the amount of glycosaminoglycans in each fraction after hydrolysis followed by determination of the hexosamines by a modified Elson and Morgan method.

Experimental data are presented to validate the various steps of the procedure. The results were found to be reproducible and accurate for fractions down to 2–5 μg of hexosamine. Small differences in the solubility properties of the glycosaminoglycan-cetylpyridinium complexes could be detected and visualized by the construction of “solubility profiles”.

Application of the procedure to histological sections of the intervertebral disc and the nasal septum cartilage revealed differences in the amount and properties of glycosaminoglycans in tissue structures 100–200 μ apart. The method should be useful to study the distribution of glycosaminoglycans at the tissue level.