PubMed Health⌕ Search

Biomedical subjects

M Moczar

Publications and source records attributed to M Moczar.

At least 55 records · Page 3Linked to original sources
PubMed1982

Isolation and characterization of lung connective-tissue glycoproteins.

1. Glycoproteins of hamster, rat and baboon lung parenchyma were investigated by using [14C]glucosamine incorporation in vitro followed by sequential extraction of the macromolecular components and characterization of the glycoproteins in the extracts. 2. Slices of lung parenchyma maintained in vitro incorporated [U-14C]glucosamine linearly with time into non-diffusible macromolecules for up to 5h. All the macromolecule-associated 14C label was present as [14C]glucosamine. 3. These 14C-labelled macromolecules were extracted from previously delipidated and salt-extracted lung by 5M-guanidinium chloride in the presence of dithiothreitol and proteinase inhibitors before (extract A1) and after (extract A2) hydrolysis of the collagen by collagenase. The [14C]glucosamine-labelled glycoproteins in extracts A1 and A2 contained 55 and 5% respectively of the total [14C]glucosamine incorporated in the lung of all three species studied. 4. The [14C]glucosamine-labelled glycoproteins were analysed by gel-filtration chromatography, sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and isoelectric focusing. The major [14C]glucosamine-labelled glycoproteins of baboon lung parenchyma had apparent mol.wts. of about 400 000, 140 000 and 65 000 with isoelectric points respectively of 4.8, 5.4 and 5.4. The hamster lung glycoproteins with isoelectric points of 4.1 and 5.8 were devoid of hydroxyproline and contained galactose, mannose and N-acetylglucosamine. These experiments indicate that several distinct glycoproteins are synthesized in situ by the cells of pulmonary parenchyma and may well play a role in its structure and function.

Amino Acids↗
PubMed1981

[Small-caliber vascular prosthesis].

Further research on biomaterials should permit the development of an adequate microarterial prosthesis. This program should also allow improvements of the presently available arterial substitutes. Various types of conduits have been tested on an experimental model: prosthetic tube, biological conduits either preserved or chemically modified. The most encouraging results have been observed with an arterial conduit, prepared from fresh aorta, treated by trypsin and glycosaminoglycans.

Animals↗
PubMed1981

Accessibility of epsilon-amino groups of lysine to guanidination in kappa-elastin from bovine ligamentum nuchae.

Kappa-Elastin contains 3.81 lysyl residues per 1000 residues of amino acids. Among these residues, free epsilon-amino groups represent about 16 p. 100, as revealed by guanidination, the buried lysyl residues (buried epsilon-amino groups) represent about 33 p. 100, as revealed by dansylation. After drastic reduction by borohydride, no aldimine bonds were detected and only 6 p. 100 of "deeply buried" amino groups of lysyl residues were detected by a second dansylation. The remaining lysines (about 46 p. 100) are engaged or inaccessible.

Animals↗
PubMed1981

Effect of lysosomotropic amine, chloroquine, on the radioactive incorporation pattern of glycosaminoglycans in human skin fibroblasts.

Control and chloroquine treated fibroblast cultures were incubated with 14C-glucosamine. The cells were separated from the medium and the pericellular matrix. The S-carboxymethylproteins in the medium were hydrolysed with trypsin and pronase. The glycosaminoglycans were treated with hyaluronidase, chondroitin AB-lyase and chondroitin ABC-lyase. The macromolecular 14C label per cell in the medium was higher in the chloroquine treated cultures than in the controls. The incorporation of the 14C-hexosamines per cell into the pericellular and intracellular compartment was not modified. The increased 14C-label in the medium of fibroblast exposed to chloroquine accounted for the increased incorporation of the 14C precursor into chondroitin 4 and 6 sulfates and dermatan sulfate.

Cells, Cultured↗
PubMed1981

Partial characterization of peptide fragment purified by isoelectrofocusing after organo alkaline hydrolysis of bovine ligamentum nuchae elastin.

Highly purified elastin from bovine ligamentum nuchae was submitted to partial alkaline hydrolysis (37 degree C, 72 H, 1 N KOH in 80 p. 100 aqueous ethanol). The non-coacervable fractions were submitted to isoelectrofocusing and five kappa-elastin fractions were obtained. The amino-acid compositions, the N-terminal amino-acids, the molecular weights and the thermolysin digests of each fraction were determined by various techniques. The average MW was about 14,500 (150 - 166 amino-acids). These results suggest that the distribution of cross-linking agents in fibrous elastin may not be uniform. The results also show that in certain cross-linked regions of similar molecular weight and size appearing to be composed of different polypeptides sequences containing different amounts of cross-links.

Animals↗
PubMed1980

Biodegradable arterial prosthesis from rat aorta.

The preparation and potential clinical use of biodegradable microarterial grafts from rat aorta were investigated. Trypsin treated arterial segments were coated with heparin or chondroitin sulfate to reduce thrombogenicity. The samples were crosslinked with formaldehyde vapors at 4 degrees C. 50 - 100 microgram glycosaminoglycans taken up per mg aorta dry weight were resistant to washing with water for 24 hrs. The covalent crosslinks introduced by formaldehyde and resistance of the grafts to proteolytic degradation. The treated grafts were implanted on 70 rats in an infrarenal aortic position. The permeability of the aldehyde crosslinked prosthesis after 21 days by patency test was lower than the patency ratio measured with fresh autologous grafts. The glycosaminoglycans associated with the prosthesis improve the patency of the crosslinked grafts by about 48%. The resistance to bacterial collagenase of the excised grafts decreased with progressing time of implantation. In the permeable prosthesis and in the contiguous aorta, elastolytic activity was demonstrated by radial diffusion in elastin-agar gels. The grafts removed after 21 days of implantation were surrounded with scar tissue. In contrast to fresh aorta, the macromolecular hydroxyprolin in the scar was readily solubilized with pepsin. The presence of the fragmented elastin and collagen fibers in the excised graft is in favour of their resorption "in vivo".

Animals↗
PubMed1979

Biosynthesis of skin collagens in normal and diabetic mice.

Synthesis of collagens in vitro was studied on minced mouse skins incubated with [3H]-proline in organ-culture conditions. A comparative study was carried out on genetically diabetic mice (KK strain) and control mice (Swiss strain). After incubation, neutral-salt-soluble and acid-soluble collagens were extracted. The insoluble dermis was digested by pepsin and type I and type III collagens separated by differential precipitation in neutral salt solutions. Type I and Type III collagens were characterized by ion-exchange and molecular-sieve chromatography, amino acid analysis and by the characterization of CNBr peptides. In diabetic-mouse skin, the relative proportion of type III collagen was significantly higher than in control-mouse skin. The incorporation of radioactively labelled proline into hydroxyproline of type III collagen was significantly faster in diabetic-mouse skin than in control-mouse skin. No significant modifications in the total collagen content of the skin or of their rates of synthesis were observed between the two strains. Alteration in the ratio of type III to type I collagen in the diabetic-mouse skin can be interpreted as a sign of alteration of the regulation of collagen biosynthesis and may be related to the structural alterations observed in the diabetic intercellular matrix.

Amino Acids↗
PubMed1979

Guanidination of kappa-elastin from bovine ligamentum nuchae.

Kappa-Elastin is exhaustively guanidinated in order to chemically modify the pre-existing lysine content to homoarginine. However the pre-existing lysine content is only modified to homoarginine content about 50 p.cent. The other lysyl-bonds are buried or/and engaged to aldi-imine bonds or other bonds. Therefore the first guanidinated kappa-Elastin is submitted to partial acide hydrolysis (HCL, 1 N, 110 degrees C for 2 hours) and submitted to a second exhaustive guanidination. The pre-existing lysin content in kappa-Elastin almost quantitively disappeared and is transformed to the corresponding homoarginine. These results are similar to those obtained by photolysis of (Iso) desmosine residues by UV light which will liberate "new" lysine containing peptides from kappa-Elastin.

Amino Acids↗
PubMed1978

Glycoproteins from the aorta.

This review deals with the data on isolation techniques, structure, physicochemical properties and biological function of glycoproteins isolated from the aorta. Some glycoproteins extracted at low ionic strengths (soluble glycoproteins) are immunologically distinct from serum glycoproteins. The designation "structural glycoprotein" was proposed for glycoproteins associated with the collagen elastin matrix. These glycoproteins are solubilized by dissociative and reducing buffers. A selective hydrolysis of the insoluble collagen prior to their extraction was also reported. The molecular weights are in the range of 53 - 72.000 and 35.000 - 27.000 daltons for the soluble and the structural glycoproteins respectively. The aorta glycoproteins are rich in polar aminoacids. The primary structure of glycoproteins from aorta is not yet established. The electrophoretic mobility and sugar content of some glycoproteins extracted at low ionic forces change with the maturation and sex. The biosynthesis of a soluble glycoprotein (glycoprotein B) and of structural glycoproteins by aortic smooth muscle cells was demonstrated "in vitro". The structural glycoproteins appear as microfibrillae in electron microscopy. Their self-aggregation may be due to hydrophobic interactions. The association of microfibrillar glycoprotein with elastin in connective tissues and in the culture medium of aortic smooth muscle cells suggests the role of glycoprotein-elastin interactions in morphogenesis.

Amino Acids↗
PubMed1977

Structural glycoprotein from the media of pig aorta. Aggregation of the S-carboxamidomethyl subunits.

Media of pig aorta was extracted with 1 M NaCl and 2 M MgCl2 to remove most of the soluble collagen, proteoglycans and glycoproteins. The glycoproteins remaining in the residue were extracted with 6 M urea-0.1 M mercaptoethanol. The urea soluble proteins were precipitated by dialysis, redissolved in 4 M guanidine-0.05 M DTT and were S-carboxamidomethylated (CM-guanidine extract). This extract was further fractionated by a variety of methods in order to separate a glycoprotein from collagen and proteoglycans. Caesium chloride density-gradient ultracentrifugation of the CM-guanidine extract separated a minor proteoglycan peak from a major glycoprotein fraction still containing some hydroxyproline. This major glycoprotein fraction was excluded as a single peak from Sephadex G 100 and G 200 in 4 M guanidinium chloride or in 6 M urea-0.2 per cent SDS. Sodium dodecylsulphate gel electrophoresis separated this high molecular weight Sephadex fraction into a major low molecular weight (approximately 35000 daltons) component and a minor high molecular weight component. This glycoprotein fraction could also be separated from a collagenous fraction and from proteoglycans by ion exchange chromatography on DEAE cellulose or by gelfiltration on Sepharose 4 B in 6 M urea-0.02 M EDTA-0.2 per cent SDS at pH 7.0. The isolated glycoprotein fraction is rich in dicarboxylic amino acids, contains galactose, mannose, (glucose), N-acetylglucosamine and sialic acid. The S-carboxamidomethyl glycoprotein preparation interacts with acid soluble calf skin collagen on isoelectric focusing in sucrose gradient in urea. This interaction is in favour of the biological role claimed for structural glycoproteins during fibrogenesis and differentiation.

Amino Acids↗