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K Kühn

Publications and source records attributed to K Kühn.

At least 145 records · Page 8Linked to original sources
PubMed1979

The covalent structure of calf skin type III collagen. I. The amino acid sequence of the amino terminal region of the alpha 1(III) chain (position 1--222).

The amino terminal 227 amino acid residues of the alpha 1(III) chain contain four CNBr peptides: alpha 1(III)CB3A (79 residues), CB3B, CB3C (6 residues each), CB7 (37 residues) and CB6 (99 residues). Fragmentation of the CNBr peptides was carried out using trypsin, chymotrypsin and the protease from Staphylococcus aureus V8. The fragments obtained were isolated by a combination of molecular sieve and ion exchange chromatography. The sequence analysis was performed according to the automated Edman degradation procedure.

Amino Acid Sequence↗
PubMed1979

The covalent structure of calf skin type III collagen. II. The amino acid sequence of the cyanogen bromide peptide alpha 1(III)CB1,8,10,2(Positions 223--402).

The cyanogen bromide peptide alpha 1-(III)CB1,8,10,2 is 180 amino acid residues in length and occupies position 223 to 402 along the alpha 1(III) chain. In order to elucidate its amino acid sequence, alpha 1(III)CB1,8,10,2 was fragmented with hydroxylamine, protease from Staphylococcus aureus V8 and trypsin. Peptides necessary for sequence analysis with the automated Edman degradation were separated using molecular and ion exchange chromatography. Edman degradation of the hydroxylamine-derived fragments resulted in the elucidation of 80% of the entire sequence. The rest was completely established by sequence analysis of some protease V8 and trypsin-derived peptides.

Amino Acid Sequence↗
PubMed1979

The covalent structure of calf skin type III collagen. III. The amino acid sequence of the cyanogen bromide peptide alpha 1(III)CB4 (positions 403--551).

The cyanogen bromide peptide alpha 1(III)CB4 comprises the sequence region from position 403 to 551 of the alpha 1(III) chain. Almost the entire sequence of this region was elucidated using two hydroxylamine- and one chymotrypsin-derived fragments for automated Edman degradation. The sequence analysis of alpha 1(III)CB4 was completed with the help of trypsin and one protease V8-derived peptide. Comparison with the corresponding region of the alpha 1(I) chain revealed a striking homology between the two chains in this region which is higher than for the entire alpha chains.

Amino Acid Sequence↗
PubMed1979

The covalent structure of calf skin type III collagen. IV. The amino acid sequence of the cyanogen bromide peptide alpha 1(III)CB5 (positions 552--788).

The cyanogen bromide peptide alpha 1(III)CB5 is 237 amino acid residues in length and occupies position 552--788 along the alpha 1(III) chain. For sequence analysis alpha 1(III)CB5 was fragmented with hydroxylamine, protease from Staphylococcus aureus V8, trypsin and the arginine-specific enzyme from mouse submaxillary gland. The peptides obtained were separated using molecular and ion exchange chromatography and sequenced with the automated Edman degradation procedure.

Amino Acid Sequence↗
PubMed1979

The covalent structure of calf skin type III collagen. V. The amino acid sequence of the cyanogen bromide peptide alpha 1(III)CB9A (position 789 to 927).

The cyanogen bromide peptide alpha 1(III)CB9A is 139 amino acid residues in length and occupies positions 789--927 along the alpha 1(III) chain. Peptides necessary for the complete sequence analysis were obtained after fragmentation of alpha 1(III)CB9B with trypsin, protease from Staphylococcus aureus V8, hydroxylamine and chymotrypsin. They were separated mainly by chromatography on Sephadex G-50 and phosphocellulose and subsequently sequenced using the automated Edman degradation procedure.

Amino Acid Sequence↗
PubMed1979

The covalent structure of calf skin type III collagen. VI. The amino acid sequence of the carboxyterminal cyanogen bromide peptide alpha 1(III)CB9B (position 928--1028).

The C-terminal cyanogen bromide peptide alpha 1(III)CB9B is 101 amino acid residues in length and occupies position 928--1028 along the alpha 1(III) chain. For sequence analysis, alpha 1(III)CB9B was fragmented with trypsin and chymotrypsin. The peptides obtained were separated using molecular sieve and ion exchange chromatography and sequenced using the automated Edman degradation procedure.

Amino Acid Sequence↗
PubMed1978

Physical evidence for the assembly of A and B chains of human placental collagen in a single triple helix.

Native collagen molecules containing A and B chains were isolated from pepsin-solubilised human chorionic and amniotic membrane extracts by fractional salt precipitation and DEAE-cellulose chromatography. They exhibited a circular dichroism spectrum, and a melting curve, characteristic for a triple-helical structure. Electron microscopical investigations of their segment-long-spacing crystallites revealed a molecule similar to those of the interstitial types I, II and III collagens. After denaturation, the A and B chains were separated by DEAE-cellulose chromatography and were consistently recovered in a ratio of 1:2. Renaturation experiments indicated that only the B chains are able to reform triple-helical molecules which are stable under conditions in vivo. The data support a molecular formula A(B)2 for the native collagen molecule.

Amino Acids↗
PubMed1977

An ultrastructural study of the mechanisms of proteinuria in rat nephrotoxic nephritis.

Nephrotoxic nephritis was induced in Sprague-Dawley and Munich-Wistar rats by the injection of rabbit antirat kidney serum. A biphasic pattern of proteinuria was induced: the heterologous phase with a peak of proteinuria occurring at 10 to 16 hours, and the autologous phase with a peak at 10 to 15 days. For morphologic studies, glomeruli were fixed by perfusion, or by drip-fixation during good blood flow. In the heterologous phase, glomerular endothelial detachment or loss and leukocytic infiltration were prominent. In the autologous phase, focal detachment of glomerular endothelium and epithelium was commonly found. At sites of endothelial loss, in both phases, endogenous albumin (demonstrated by an ultrastructural immunoperoxidase technique), but not intravenously injected ferritin, showed abnormally deep penetration into the glomerular basement membrane. At sites of epithelial loss, found in the autologous phase, both albumin and ferritin were detected throughout the glomerular basement membrane. It is proposed that, in glomerular disease, leakage of plasma proteins may occur across the glomerular basement membrane at sites of endothelial or epithelial detachment.

Albumins↗
PubMed1977

[Collagen biosynthesis as an example for the regulation of gene expression in mesenchymal cells (author's transl)].

The polymorphism of collagen was the initial observation which stimulated the interest in the regulation of the gene expression of this eucaryotic protein. In the first set of experiments it was shown that a fibroblast from fetal skin possesses the capability to synthesize both type I and type III collagen at the same time. In a second line of investigations, evidence was obtained that in the course of the degenerative osteoarthrosis chondrocytes switch from synthesis of type II collagen to synthesis of type I collagen. A similar observation was made when enzymatically isolated chondrocytes from the sterna of embryonic chicken were grown under tissue culture conditions. This change in synthesis probably reflects a change in gene regulation which might be caused by an as yet unknown disturbance in the cell matrix interaction.

Animals↗
PubMed1976

Immunohistological study on collagen in cartilage-bone metamorphosis and degenerative osteoarthrosis.

Synthesis of collagen by chondrocytes was studied by immunofluorescence using antibodies specific for type I, II and III collagen. The following tissues and culture conditions were chosen for this immunohistological study: normal articular cartilage, epiphyseal growth cartilage, cartilage undergoing osteoarthrotic degeneration, suspension culture and monolayer culture. While type II collagen is the unique collagen all over hyaline cartilage, type I collagen is produced by hypertrophic chondrocytes in the growth plate. In addition, chondrocytes in osteoarthrotic areas of articular cartilage synthesize type I collagen. Under in vitro culture conditions, chondrocytes initially product type II collagen and synthesize later on type I collagen. The change of synthesis from type II to type I collagen is more rapid in monolayer than in suspension culture. It is concluded that the presence of matrix compounds and the cellmatrix interaction as well are necessary to maintain synthesis of type II collagen in chondrocytes. Alterations in the cell-matrix interactions are shown to occur in the hypertrophic zone of the epiphyseal growth plate, in cartilage undergoing osteoarthrotic degeneration as well as in chondrocytes grown in culture. Thus, change in the control of gene activity may subsequently lead to change in collagen synthesis. It is possible that the synthesis of type I collagen, which cannot fulfil the physiological function of a structural element in cartilageneous tissue, is a crucial factor in the process of osteoarthrosis.

Cartilage↗
PubMed1976

Characterization and distribution of collagen types in arterial heterografts originating from the calf carotis.

The immunohistochemical results showed that the distribution of the collagen types in calf carotis is the same as that found in human arteries. Mechanically prepared and ficin-treated vessels showed a removal of cells, elastic fibres and type II collagen. The remaining collagen meshwork was shown by immunohistochemical methods and also by amino acid analysis to be type I collagen. Because of its structural, chemical and immunological properties, the protease treated, aldehyde stabilised Arteria carotis communis of the calf is suitable as a replacement material for arterial segments. Initial successes using man as a recipient support the stated conclusion.

Amino Acids↗