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O Smidsrød

Publications and source records attributed to O Smidsrød.

28 records · Page 2Linked to original sources
PubMed1987

The molecular size and shape of xanthan, xylinan, bronchial mucin, alginate, and amylose as revealed by electron microscopy.

Electron microscopy of some selected, vacuum-dried and rotary-shadowed, polyelectrolytic polysaccharides and glycoproteins adsorbed to mica indicates that this technique can yield reliable information about polymer conformation for chains with persistence lengths q exceeding about 10 nm. Statistical analyses of the local polymer tangent-direction yield q = 150 nm for double-stranded xanthan, q = 60 nm for single-stranded xanthan, q = 45 nm for xylinan, q = 16 nm for alginate (90% beta-D-mannuronic acid), and q = 15 nm for human-bronchial mucin. These values are all in adequate agreement with values of q obtained by using other techniques. Amylose, on the other hand, appears as non-randomly aligned chains. The observed contour lengths of amylose indicate a mass per unit length of 1440 dalton/nm, consistent with a pseudo-helical conformation.

Alginates↗
PubMed1985

Partial Chemical and Physical Characterization of Two Extracellular Polysaccharides Produced by Marine, Periphytic Pseudomonas sp. Strain NCMB 2021.

The marine bacterium Pseudomonas sp. strain NCMB 2021, which can attach to solid, and especially hydrophobic, surfaces, elaborates two different extracellular polysaccharides in batch cultures. One (polysaccharide A) was produced only during exponential growth and contained glucose, galactose, glucuronic acid, and galacturonic acid in a molar ratio of 1.00:0.81:0.42:0.32. It produced viscous solutions, formed gels at high concentrations, and precipitated with several multivalent cations. The other (polysaccharide B) was released at the end of the exponential phase and in the stationary phase. It contained equimolar amounts of N-acetylglucosamine, 2-keto-3-deoxyoctulosonic acid, an unidentified 6-deoxyhexose, and also O-acetyl groups. Despite its high molecular weight (10 to 10 as judged by gel filtration), the polysaccharide produced aqueous solutions with very low viscosities and was also soluble in 90% aqueous phenol, 80% methanol, and 80% ethanol.

Journal Article↗
PubMed1984

Lysozyme and lactoferrin in sputum from patients with chronic obstructive lung disease.

The two basic proteins lysozyme and lactoferrin have been isolated from solubilized mucoid sputum from patients with chronic bronchitis in one step by cation exchange chromatography. In sputa from 13 patients with chronic bronchitis their mean concentrations were 0.4 g/l and 0.7 g/l, respectively, representing 6.6% and 11.5% of the total amount of solubilized protein. Lysozyme and the acid mucin glycoproteins of sputum formed aggregates at low ionic strength, probably as a result of electrostatic interactions between the two. Although only aggregates were formed and not a viscoelastic fluid or a gel, these interactions may contribute to the viscoelastic properties of native sputum.

Chromatography, Ion Exchange↗
PubMed1982

Preparation of enzymically active lysozyme from sputum and its distribution between the sol and gel phases.

An improved method for the isolation and purification of lysozyme from sputum from bronchitic patients is presented. Enzymically active lysozyme in pure form was obtained in practically quantitative yields. The method was used to quantify the lysozyme content and to determine its distribution between the sol and gel phases of the secretion, which were separated by centrifugation. It was shown that lysozyme is concentrated in the mucin-containing gel phase, from which it can be liberated with high concentrations of salt. Evidence supporting an electrostatic binding mechanism between mucin and lysozyme is presented.

Carbohydrates↗
PubMed1980

The importance of lysozyme for the viscosity of sputum from patients with chronic obstructive lung disease.

Addition of lysozyme (1 g/l) to sputum from patients with chronic obstructive lung disease increased the viscosity of the material significantly. The effect was prevented by addition of salt (LiCl) in the high concentration (0.25 mol/l). The sole addition of salt decreased the viscosity of native sputum. These results together with our earlier [5] studies of the interaction between the positively charged lysozyme and the negatively charged mucin molecules in model systems, indicate that lysozyme acts as a cross-linking agent in mucus by an electrostatic mechanism. Lysozyme is thus, at least partly, responsible for building up a macromolecular network giving mucus its characteristic gel-like properties.

Chlorides↗
PubMed1980

Quantitation of proteins in sputum from patients with chronic obstructive lung disease. I. Determination of immunoglobulin A.

Samples of sputum from nine patients with chronic obstructive lung disease were collected every morning for 5 consecutive days, and their mean apparent viscosities were determined. After a standard solubilization procedure, the concentration of immunoglobulin A (IgA) in each sample was determined by quantitative immunodiffusion and also by an immunofluorimetric method, using dimeric IgA purified from colostrum as a standard. The two methods gave diverging results probably reflecting different sensitivities of the techniques to various classes of IgA (monomers, dimers and polymers). The concentration of IgA was found to vary from 1.2 to 3.9 g/l with a mean value of 2.3 g/l for the 45 samples using the immunodiffusion technique, and from 1.3 to 4.9 g/l with a mean value of 3.5 g/l using the immunofluorimetric method. In agreement with earlier observations, a weak correlation was shown between the concentration of IgA in the samples and their mean viscosities. A similar correlation was, however, demonstrated between IgA and the total content of protein in the soluble part of the samples. It could therefore not be decided whether IgA itself or other proteins in the sputa were responsible for the observed effect on viscosity.

Carbohydrates↗
PubMed1980

Quantitation of proteins in sputum from patients with chronic obstructive lung disease. II. Determination of albumin, transferrin, alpha1-acid glycoprotein, IgG, IgM, lysozyme and C3-complement factor.

Albumin, transferrin, alpha1-acid glycoprotein, IgA, IgG, IgM, lysozyme and C3-complement factor have been immunologically determined in sputum and serum samples from 16 patients with chronic bronchitis. The sputa were effectively solubilized prior to the analysis. This is necessary for correct determination of the compositions of sputum. IgA (approx. 3 g/l) and lysozyme (approx. 1 g/l) were present in the highest concentrations. Lactoferrin was qualitatively shown to be present in all the sputa. The concentration of IgG, albumin and transferrin were much higher in the sera than in the sputa, their presence in sputum probably being a result of a passive "leakage" from serum. The ratios for IgA, IgM and lysozyme indicated that these macromolecules are locally synthesized in the respiratory tract. The concentrations of IgA and lysozyme were closely correlated, indicating that the biosynthesis of secretory IgA and bronchial lysozyme may be coupled or controlled by the same mechanism. Except for a weak correlation between the concentration of IgA in sputum and viscosity, no such correlations were obtained for the other proteins determined.

Complement C3↗
PubMed1980

Electron microscopy of mucin from sputum in chronic obstructive bronchitis.

Sputum from patients with chronic obstructive bronchitis has been fractionated on Sepharose columns after treatment with urea 6 mol/l at pH 12.5 followed by neutralization. The "mucin" fraction, which contained 70% carbohydrate and 30% protein was studied in the electron microscope after staining with phosphotungstic acid. Positively stained, thread-like, irregular contours of the mucin molecules could be demonstrated with lengths varying from 2,000 to 5,000 nm, corresponding to molecular weights between 2 X 10(6) and 6 X 10(6). This correlates fairly well with estimates from the literature of the size of these molecules.

Bronchitis↗