Preliminary Characterization of Mucin from Effusions of Cleft Palate Patients

1993 ◽  
Vol 109 (6) ◽  
pp. 1000-1006 ◽  
Author(s):  
David A. Hutton ◽  
Fiona J. J. Fogg ◽  
George Murty ◽  
John P. Birchall ◽  
Jeffrey P. Pearson
Keyword(s):  
Amino Acid ◽  
Cleft Palate ◽  
Middle Ear ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Equilibrium Density ◽  
Hydrodynamic Size ◽  
Normal Children ◽  
Large Molecular Weight

Middle ear effusions from children undergoing myringotomy were classified into three groups — Cleft palate, thick (mucoid), and thin (serous). Mucin was purified from each of the three groups using CsCl equilibrium density gradient centrifugation. Analysis of the cleft palate mucin on Sepharose CL-2B showed it was excluded and therefore of large molecular weight. It could be broken down Into smaller glycopeptide units by proteolysis and these glycopeptides had, based on elution position, a larger hydrodynamic size than those from the thick mucin. Intrinsic viscosity measurements demonstrated that the intact mucins could be ranked in order of molecular space occupancy; cleft palate > thick > thin. Amino acid analysis showed the cleft palate mucin to have an amino acid composition similar to other mucins, with serine, threonine, and proline constituting 41% by weight of the protein core. Thiol analysis gave evidence of a possible difference in polymerization between the three mucins, in that thin (the smallest mucin) contained the lowest number of thiols. This preliminary analysis of cleft palate mucin suggests a mucin with larger glycopeptide units forming an intact mucin of larger hydrodynamic size than either thick or thin middle ear mucins from anatomically normal children.

Dna Synthesis in Purified Populations of Avian Erythroid Cells

1972 ◽  
Vol 10 (1) ◽  
pp. 27-46
Author(s):  
A. F. WILLIAMS
Keyword(s):  
Biochemical Characterization ◽  
Bone Marrow Cells ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Experimental System ◽  
Equilibrium Density ◽  
Polychromatic Erythrocytes ◽  
Type Size ◽  
Haemoglobin Content

By the use of equilibrium density-gradient centrifugation erythroblasts and early polychromatic erythrocytes have been isolated from avian anaemic bone marrow. Cells from both the unfractionated and purified preparations have been characterized in terms of their histological type, size, haemoglobin content and ability to synthesize DNA. Erythroblasts were the only cells to synthesize DNA and it appeared that their progeny, the polychromatic erythrocyte, failed to enter a new S phase. The experimental system described allows biochemical characterization of earlier stages of avian erythropoiesis than has previously been possible.

scholarly journals Proteoglycans of the intervertebral disc. Absence of degradation during the isolation of proteoglycans from the intervertebral disc

1979 ◽  
Vol 179 (3) ◽  
pp. 573-578 ◽  
Author(s):  
R L Stevens ◽  
P G Dondi ◽  
H Muir
Keyword(s):  
Intervertebral Disc ◽  
Density Gradient ◽  
Core Protein ◽  
Density Gradient Centrifugation ◽  
Chondroitin Sulphate ◽  
Gradient Centrifugation ◽  
Equilibrium Density ◽  
Hydrodynamic Size ◽  
Laryngeal Cartilage ◽  
Cartilage Proteoglycans

Proteoglycans extracted with 4M-guanidinium chloride from pig intervetebral discs, and purified by equilibrium density-gradient centrifugation in CsCl, were of smaller hydrodynamic size than those extracted and purified in the same way from the laryngeal cartilage of the same animal. Whether this difference in size arose from degradation during the extraction and purification of the proteoglycans of the disc was investigated. Purified proteoglycans labelled either in the chondroitin sulphate chains or in the core protein were obtained from laryngeal cartilage by short-term organ culture. These labelled proteoglycans were added at the beginning of the extraction of the disc proteoglycans, and labelled cartilage and unlabelled disc proteoglycans were isolated and purified together. There was no appreciable loss of radioactivity after density-gradient centrifugation nor decrease in hydrodynamic size of the labelled cartilage proteoglycans on chromatography on Sepharose 2B, when these were present during the extraction of disc proteoglycans. It is concluded that disc proteoglycans are intrinsically of smaller size than cartilage proteoglycans and this difference in size does not arise from degradation during the extraction.

scholarly journals Characterization of gastric mucoproteins isolated by equilibrium density-gradient centrifugation in caesium chloride

1974 ◽  
Vol 141 (3) ◽  
pp. 633-639 ◽  
Author(s):  
Bryan J. Starkey ◽  
David Snary ◽  
Adrian Allen
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Gradient Centrifugation ◽  
Gel Filtration ◽  
Equilibrium Density ◽  
Amino Acid Residues ◽  
Gastric Mucus ◽  
Terminal Amino Acid ◽  
Terminal Amino

1. The mucoprotein from pig gastric mucus has been purified by equilibrium centrifugation in a CsCl gradient. 2. This procedure removes the non-covalently bound protein, which is closely associated with the mucoprotein and not easily removed from it by gel filtration. 3. The purified mucoprotein is separable by gel filtration into a high-molecular-weight mucoprotein A (mol.wt. 2.3×106) and a low-molecular-weight mucoprotein B/C (mol.wt. 1.15×106). 4. These two mucoproteins have the same chemical analysis namely fucose 11.3%, galactose 26%, glucosamine 19.5%, galactosamine 8.3% and protein 13.6%. 5. Mucoprotein A contains 3.1% ester sulphate. 6. These mucoproteins are isolated without enzymic digestion and have a higher protein content than the blood-group-substance mucoproteins from proteolytic digestion of gastric mucus. Detailed amino acid analysis shows that the extra protein in the non-enzymically digested material is composed of amino acids other than serine and threonine. 7. Mucoproteins A and B/C contain respectively 130 and 9 half-cystine residues per molecule of which about 78 and 6 residues are involved in disulphide linkages. 8. Cleavage of these disulphide linkages by mercaptoethanol splits both mucoproteins into four equally sized subunits of mol.wt. 5.2×105for mucoprotein A and 2.8×104for mucoprotein B/C. 9. The sole N-terminal amino acid of mucoprotein A is aspartic acid, whereas mucoprotein B/C has several different N-terminal amino acid residues.

scholarly journals Isolation and partial characterization of rat duodenal-gland (Brunner's-gland) mucus glycoprotein

1982 ◽  
Vol 203 (3) ◽  
pp. 779-785 ◽  
Author(s):  
H L Smits ◽  
P J M van Kerkhof ◽  
M F Kramer
Keyword(s):  
Small Intestine ◽  
Chemical Composition ◽  
Protein Content ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Mucous Cells ◽  
Present Evidence ◽  
Mucus Glycoprotein ◽  
Duodenal Glands

A mucus glycoprotein was isolated from the duodenal glands of the rat and purified by repeated density-gradient centrifugation. The characterized glycoprotein is unique to the mucous cells of the duodenal glands and is not present in parts of the small intestine devoid of these glands. The chemical composition of the purified glycoprotein is characteristic for glycoproteins of the mucin-type. Its protein content is relatively high and amount to 35% by weight. No neuraminic acid and little sulphate (2%) is present. Evidence is presented that the native glycoprotein is built up from subunits held together via disulphide bridges in a non-glycosylated region of the protein core.

scholarly journals Biosynthesis of proteoglycans in cartilage slices. Fractionation by gel chromatography and equilibrium density-gradient centrifugation

1972 ◽  
Vol 126 (4) ◽  
pp. 791-803 ◽  
Author(s):  
T. E. Hardingham ◽  
Helen Muir
Keyword(s):  
Density Gradient ◽  
Density Gradient Centrifugation ◽  
Chondroitin Sulphate ◽  
Gradient Centrifugation ◽  
Guanidine Hydrochloride ◽  
Specific Radioactivity ◽  
Equilibrium Density ◽  
Gel Chromatography ◽  
Sulphate Content

The kinetics of incorporation of [35S]sulphate into slices of pig laryngeal cartilage in vitro was linear with time up to 6h. The specific radioactivities of the extracted proteoglycans (containing about 80% of the uronic acid of the cartilage) and the glycosaminoglycans remaining in the tissue after extraction were measured after various times of continuous and ‘pulse–chase’ radioactivity incorporation. Radioactivity was present in the isolated chondroitin sulphate after 2 min, but there was a 35min delay in its appearance in the extractable proteoglycan fraction. Fractionation of the proteoglycans by gel chromatography showed that the smallest molecules had the highest specific radioactivity, but ‘pulse–chase’ experiments over 5h did not demonstrate any precursor–product relationships between fractions of different size. Equilibrium density-gradient centrifugation in 4m-guanidine hydrochloride showed that among the proteoglycan fractions the specific radioactivity increased as the chondroitin sulphate content decreased, but with preparations from ‘pulse–chase’ experiments there was again no evidence for precursor–product relationships between the different fractions. Differences in radioactive incorporation would seem to reflect metabolic heterogeneity within the proteoglycans extracted from cartilage. This may be due either to a partial separation of different types of proteoglycans or to differences in the rates of degradation of the molecules of different size and composition as a result of the nature and specificity of the normal degrading enzymes. The results suggest that molecules of all sizes were formed at the same time.

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