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PubMed1978

[The judgement of collagen metabolism by hydroxyproline in plasma and urine and plasma collagenic peptidase under different diet (author's transl)].

In 34 subjects--coal workers with pneumoconiosis, patients with collagenic diseases and healthy subjects--the daily urinary excretion of hydroxyproline (HP) and the plasma concentrations of HP and of collagenic peptidase have been measured during one week under HP-free and HP-enriched diet. It is shown that a 24-hour period of HP-free diet is necessary and sufficient before collecting urine or plasma for diet independent measurements of total or non-protein bound HP. Concentrations in plasma correlate well with the amounts excreted in urine. Collagenic peptidase is independent from the diet and well suited for assessment of the activity of the metabolism of collagene. There are no differences between healthy subjects and coal workers with pneumoconiosis.

Adult↗

PubMed1977

[Comparison of the cyanogen bromide peptides of vitreous body collagen and type II collagen (author's transl)].

Pepsin-soluble collagen was isolated from bovine vitreous humor. This collagen showed only one alpha-chain in disc electrophoresis, migrating in the alpha1-chain position and between the alpha- and beta-components some colored bands were visible. The disc electrophoretic patterns of the cyanogen bromide peptides of pepsin-soluble vitreous body collagen and pepsin-soluble type II collagen revealed no identity.

Animals↗

PubMed1978

Glomerular basement membrane collagen and activities of the intracellular enzymes of collagen biosynthesis in congenital nephrotic syndrome of the Finnish type.

The composition of pepsin-solubilized glomerular basement membrane (GBM) collagen was studied in kidneys from patients with congenital nephrotic syndrome of the Finnish type (CNF). The 3-hydroxyproline content in the GBM collagen in CNF was only about one half of that noted in the controls. The alanine content was slightly higher in CNF, but no differences were found in the contents of the other amino acids or carbohydrates. Analysis of the GBM collagen by sodium dodecyl sulphate polyacrylamide gel electrophoresis after reduction indicated a lower proportion of one of the major polypeptide chains in CNF than in the controls, while a higher proportion of one low molecular weight minor component was noted. The activities of the five intracellular enzymes of collagen biosynthesis, including prolyl 3-hydroxylase, were not significancy altered in the CNF kidney cortex samples when compared with the controls.

Amino Acids↗

PubMed1978

Covalent structure of collagen: amino acid sequence of five consecutive CNBr peptides from type III collagen of human liver.

Type III collagen was solubilized from human liver by limited pepsin digestion and purified by differential salt precipitation and carboxymethylcellulose chromatography. Digestion with cyanogen bromide yielded the nine distinct peptides previously described and an additional tripeptide not recognized in earlier studies. Five of these peptides, alpha1 (III)-CB1, 2, 4, 8, and 10, were further purified by molecular sieve and/or ion exchange chromatography. They contained 12, 40, 149, 125 and 3 amino acid residues, respectively. The amino acid sequence of these peptides was determined by automated Edman degradation of tryptic (before and after maleylation), chymotryptic, thermolytic or hydroxylamine-derived peptide fragments as well as the intact peptides. The alignment of these five peptides within the collagen chain is deduced to be 1-8-10-2-4 by homology with known alpha1 (I) sequences. The known CNBr peptide alignment of the NH2-terminal portion of type III collagen so far would, therefore, be alpha1 (III)-CB3-7-6-1-8-10-2-4 and correspond to the homologous region of alpha1 (I)-CB0-1-2-4-5-8-3 or residues 11-567 of the alpha1 (III) collagen chain.

Amino Acid Sequence↗

PubMed1977

Covalent structure of collagen: amino acid sequence of cyanogen bromide peptides from the amino-terminal segment of type III collagen of human liver.

Human liver type III collagen was prepared by limited pepsin digestion, differential salt precipitation, and carboxymethylcellulose chromatography. Cyanogen bromide digestion of purified type III collagen chains yielded nine distinct peptides. Three peptides, alpha1(III)-CB3, alpha1(III)-CB7, and alpha1(III)-CB6, were isolated by carboxymethylcellulose chromatography and Sephadex G-50 SF gel filtration. Automated Edman degradation together with selective hydroxylamine cleavage and chymotrypsin and trypsin digestion enabled determination of their complete amino acid sequence. Compared with type I collagen, the data show tentative homology of alpha1(III)-CB3 with alpha1(I)-CB1, alpha1(I)-CB2, and alpha1(I)-CB4; alpha1(III)-CB7 with alpha1(I)-CB5; and alpha1(III)-CB6 with the amino-terminal portion of alpha1(I)-CB8. Close interspecies homology was found between the sequences presented here with 90 residues of alpha1(III)-CB3 and 26 of alpha1(III)-CB8 of calf aorta. The present study establishes the amino acid sequence of 229 residues near the amino terminus or nearly one-quarter of the type III collagen chains. The disaccharide, Glc-Gal, was convalently bound to hydroxylysine at a position corresponding to the same location in the alpha1(I) chain.

Adult↗

PubMed1975

A 13C nuclear magnetic resonance and circular dichroism study of the collagen-gelatin transformation in enzyme solubilized collagen.

Natural abundance Fourier transform 13C nuclear magnetic resonance (13C NMR) were obtained for enzyme solubilized collagen at 1 degrees intervals through the transition region. The transition of collagen molecules from the rigid triple helical state to single-stranded, random-coil state is accompanied by a change from broadened carbon resonances unobservable under high-resolution conditions to narrow line spectra. Thus distinction can be made between helical and random-coil states of individual residues. The transition is monophasic, as determined by examination of 14 different carbon resonances, and the entire structure is found to melt cooperatively over a temperature interval of 5 +/- 1 degrees. All the residues seem to be involved in the unfolding process concurrently. The transition was also studied by examining the changes in the circular dichroism spectrum brought about by heating. The experiments corroborated the observation that the transition proceeded cooperatively over a temperature interval of 4 degrees. Enzyme soluble collagen is seen to melt less cooperatively than native collagen. The enthalpy change was determined by assuming an equilibrium between three random coil gelatin chains and tropocollogen molecules. From the enthalpy, the average length of the tripeptide sequences (70-85) involved in the transition can be estimated. The shortening of the cooperative unit could arise as a result of some alteration of the native conformation through proctase treatment.

Animals↗

PubMed1978

Effect of intermittent high altitude hypoxia on the synthesis of collagenous and non-collagenous proteins of the right and left ventricular myocardium.

The incorporation of 14C-proline into collagenous and non-collagenous proteins of the right and left ventricular myocardium was investigated in rats exposed to intermittent high altitude hypoxia. Experimental results have shown that even in control animals significant differences exist in the concentration and synthesis of individual protein fractions between the right and left ventricular myocardium. Long-term exposure to intermittent high altitude hypoxia induced a significantly increased concentration of collagenous and non-collagenous proteins in both ventricles. The incorporation of 14C-proline was not affected at this period (ie period of stabilised hypertrophy) in either of the fractions studied.

Altitude Sickness↗

PubMed1978

Effect of hydrochlorothiazide on urine saturation with brushite, in vitro collagen calcification by urine, and urinary inhibitors of collagen calcification.

To clarify further the beneficial effect of thiazide diuretics on recurrent calcium nephrolithiasis, the effect of short-term hydrochlorothiazide therapy on urine saturation with brushite (CaHPO(4).2H(2)O), in vitro collagen calcification by urine, and urinary inhibitors of calcification was studied.In 22 patients with idiopathic calcium oxalate/phosphate stones the urine calcium excretion decreased, the urine magnesium excretion increased and the urine magnesium/calcium ratio increased significantly (P < 0.001) during hydrochlorothiazide therapy. Supersaturation of the urine with brushite, which was present in 19 of the 22 patients, was reduced significantly (P < 0.001) in all during thiazide therapy, and to the undersaturated range in 16. The ability of urine to calcify collagen in vitro also decreased significantly (P < 0.001) during thiazide therapy, a change that correlated significantly (r = 0.4513, P < 0.05) with the decrease in brushite saturation. The concentration of urinary inhibitors of calcification, as determined with an in vitro collagen calcification system, was decreased significantly (P < 0.01) by thiazide therapy.It was concluded that, in addition to decreasing urine calcium excretion and increasing urine magnesium excretion, thiazide diuretics decrease the urinary brushite saturation and thus may prevent spontaneous nucleation or crystal growth, or both, of calcium phosphate. The ability of thiazides to decrease collagen calcification in vitro suggests that they may also prevent crystal growth on a nidus of organic matrix. Thiazides do not appear to act by increasing the excretion of urinary inhibitors of calcification.

Adult↗

PubMed1975

A passive agglutination method using collagen-coated tanned sheep erythrocytes to demonstrate collagen-glycosaminoglycan interaction.

A haemagglutination method originally designed to detect and measure antibody has been shown to be capable of monitoring interactions of glycosaminoglycans and collagen in vitro under physiological conditions of pH and ionic strength. In this system, dermatan sulphate and chondroitin 4-sulphate interact at higher dilutions ('higher titres') with collagen than do chondroitin 6-sulphate or keratan sulphate. The results are relevant to studies of anti-collagen antibodies in connective tissue fluids and extracts, as well as to connective tissue physiology.

Animals↗

PubMed1977

Ordering of cyanogen bromide peptides of type III collagen based on their homology to type I collagen: preservation of sites for crosslink formation during evolution.

The order of the cyanogen-bromide-derived peptides from alpha 1 (III) chains of pepsin-solubilized calf skin collagen was found to be 3A-3B-3C-7-6-1,8,2-4-5-9A-9B. The amino-acid sequences of the NH2-terminal region of all peptides were determined by Edman's automated degradation procedure. The alignment of the peptides along the peptide chain was established by searching for the best homology between the partial sequences of the cyanogen bromide peptides from the alpha 1 (III) chain and the completely known sequence of the alpha 1 (I) chain. Characterization of three cyanogen-bromide-derived double peptides provided confirmation of the deduced order. A sequence Gly-Met-Hyl-Gly-His-Arg-Gly-Phe- was established near the NH2-terminus and a sequence Gly-Ile-Hyl-Gly-His-Arg-Gly-Phe near the COOH-terminus of the alpha 1(III) chain. Identical sequences have been found in the corresponding regions of the alph 1(I) chain. They include hydroxylysine, a site for intermolecular crosslink formation. Because these sequences are conserved during evolution of the collagen molecule, they are probably important for collagen structure and function.

Amino Acid Sequence↗

PubMed1975

Demonstration of antibodies to collagen and of collagen-anticollagen immune complexes in rheumatoid arthritis synovial fluids.

Twenty-nine synovial fluids from patients with rheumatoid arthritis (RA) and 10 synovial fluids from patients with other joint diseases were investigated with regard to the presence of antibodies to denatured human collagen and of collagen-anticollagen immune complexes. 12 of the 29 RA synovial fluids showed anticollagen titres from 1:16 to 1:512 in passive haemagglutination. Only one patient in the group with no arthritis had a significant anticollagen titre of 1:32. Digestion of the synovial fluids with bacterial collagenase resulted in an anticollagen titre increase from two to four dilution steps in 9 of the RA fluids, while 6 previously negative RA synovial fluids showed anticollagen titres from 1:32 to 1:28 after digestion with collagenase. These results indicate the existence of collagen-anticollagen immune complexes in 15 of the 29 RA synovial fluids investigated.

Animals↗

PubMed1978

The visualization of individual collagen molecules and aggregates in collagen solution: the effect of preparation and sampling techniques.

The use of electron microscopic observations to characterize the state of aggregation of collagen molecules in solution has been examined from the point of view that the observed structures must be compatible with the physical chemical properties of the solution. The common procedure of addition of droplets of a collagen solution to a grid followed by negative staining produces aggregates on the grid which could not have represented the aggregation state in solution. Closer representation of fibril diameters can be achieved by freeze cleave-etch methods. The best representation of the state of aggregation in collagen solutions can be achieved by use of a careful drop-washing procedure. This procedure, described in detail, permits correlation between intrinsic viscosity and electron microscopic observations.

Collagen↗

PubMed1978

Ultrastructure of the collagen fibril. I. Some features of the structure of the collagen fibril.

In the human ovary, thyroid gland and in the rat tail tendon the plasma membrane of fibroblasts may "disappear" or "dissolve", leading to a direct contact of the cytoplasm with extracellular space. Extracellular filaments and collagen fibrils may grow directly out of the cytoplasm and from extracellular vesicles and cellular remnants. The filaments are complex structures composed of 3 to 5 subfilaments. Adjacent collagen fibrils are connected with interfibrillar bridges. In the rat tail tendon 2 different types and opposite orientated fibrils are found. After enzymatic treatment it becomes clear that the collagen fibril has a tridimensional organization and is composed of filaments and amorphous cementing matrix. The matrix is easily affected by various enzymes and washed away, revealing thus the inner spiral structure of the fibril.

Adolescent↗

PubMed1977

Covalent structure of collagen: amino-acid sequence of chymotryptic peptides from the carboxyl-terminal region of alpha2-CB3 of chick-skin collagen.

The amino acid sequence of chymotryptic peptides C4 and C5 which together make up 206 COOH-terminal residues of alpha2-CB3 of chick skin collagen is described. This in combination with the sequence of 132 residues from the amino-terminal region published earlier [Dixit, Seyer, and Kang (1977) Eur. J. Biochem. 73, 213-221] completes the total amino acid sequence of the large CNBr peptide, alpha2-CB3 of chick skin collagen. The amino acid sequence was determined by automated Edman degradation of intact peptides C4 and C5 and their respective tryptic and maleylated tryptic peptides, and thermolytic peptides of C4. The comparison of the sequence with the homologous segment of alpha1(I) chain showed striking variance of over 51% within the same species.

Amino Acid Sequence↗

PubMed1975

Insoluble collagen I. The effect of substrate weight on the rate of solubilisation of polymeric collagen fibrils by bacterial collagenase.

The enzymic solubilisation of insoluble collagen fibrils by bacterial collagenase has been examined employing unlabelled polymeric collagen fibrils (PC), rhodamine labelled fibrils (RB-PC), and fluorescein labelled fibrils (F-PC) as substrates. The presence of the label did not affect the kinetics of enzyme digestion but enabled the solubilized products to be rapidly estimated. The quantity of substrate used was found to play a major role in determining the quantity of peptides solubilised by a given enzyme concentration. It is suggested that in the PC fibrils only a limited number of TC molecules were suitably located to form an enzyme substrate complex with bacterial collagenase. Conditions were found in which the F-PC and RB-PC could be used as substrates in the assay of this enzyme.

Bacteria↗

PubMed1976

The cyanogen bromide peptides of bovine soluble and insoluble collagens. I. Characterization of peptides from soluble type I collagen by sodium dodecylsulphate polyacrylamide gel electrophoresis.

Acid soluble collagen and purified alpha1 and alpha2 chains were prepared from bovine skin and digested with cyanogen bromide. The resultant peptides were separated by electrophoresis on polyacrylamide gels containing sodium dodecylsulphate. Thirteen peptides obtained from the alpha1 chain and two from the alpha2 chain were identified as overlapping sequences containing methionine-derived peptide bonds not cleaved during the reaction. Those uncleaved peptides from the alpha1 chain accounted for approximately 30% of the total digest, as determined by planimetry on the staining profiles, and their relative proportions indicated that efficiency of cleavage at specific methionine residues was dependent upon position in the sequence. Alpha1CB5-8 was most resistant to cleavage while alpha1CB0,1-2 and alpha1CB7-6 were most susceptible. Peptides of a 2:1 (w/w) mixture of alpha1 and alpha2 chains and of the acid-soluble collagen gave electrophoretograms which were essentially a summation of those obtained from the individual chains.

Animals↗

PubMed1979

[Effect of exogenous collagen on the metabolism of burns in rats; the collagen treatment of large superficial excision wounds].

In an animal experiment study the effect of collagen sponge treatment on skin wounds was examined. In a test for defense mechanism, the bandage material was accepted without any disturbance of the surrounding tissue. It could also be removed without any damage to the wound area while renewing the covering bandage. In contrast to the controls, there was a statistically significant difference in the decreasing wound area. No tract formation of the wound edges was observed in the experimental group, and histologically the wounds showed an earlier fiber formation with functional orientation toward the wound surface. The advantages of treatment using collagen instead of inert material include better compatibility, a positive cosmetic effect, and a stimulation of wound healing without the necessity of a two-stage transplantation.

Animals↗

PubMed1979

Covalent structure of collagen: amino acid sequence of alpha 2-CB5 of chick skin collagen containing the animal collagenase cleavage site.

The amino acid sequence of the 112 residues from the amino terminus of alpha 2-CB5 from chick skin collagen was determined by automated sequential degradation of intact alpha 2-CB5 and several chymotryptic and tryptic peptides. This segment of the peptide includes the site of the action of animal collagenases. As compared to the sequence around the alpha 1 cleavage site, the alpha 2 sequence is notable for the remarkable constancy of the residues to the amino side and the relative abundance of hydrophobic residues to the carboxyl side of the cleavage site, suggesting that these features are important in the recognition by the enzyme. The sequence of this region of the alpha 2 chain is consistent with the Gly-X-Y triplet structure and the preference of certain residues for either the X or Y position in distribution. However, three of the six residues of leucine were found in the Y position rather than the X position. Leucine residues were found only once in the Y position in the alpha 1 (I) chain. This preference does not appear to hold in the alpha 2 chain.

Amino Acid Sequence↗