The structure of type IX collagen.
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Amino Acid Sequence↗
Biomedical subjects
M van der Rest
Publications and source records attributed to M van der Rest.
Human placenta type V collagens. Evidence for the existence of an alpha 1(V) alpha 2(V) alpha 3(V) collagen molecule.
Human type V collagen was purified from placenta and found to contain alpha 1(V), alpha 2(V), and alpha 3(V) chains in varying ratios. Using any of three independent nondenaturing methods (phosphocellulose chromatography, high-performance ion-exchange chromatography on IEX-540 DEAE, and ammonium sulfate precipitation), this preparation could be resolved into two fractions. Analysis of the two fractions by sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated that one fraction contained alpha 1(V) and alpha 2(V) in a 2:1 ratio and the other contained alpha 1(V), alpha 2(V), and alpha 3(V) in a 1:1:1 ratio. When the crude placental type V collagen was electrophoresed under nondenaturing conditions, two bands were observed, one co-migrating with purified (alpha 1(V]2 alpha 2(V) and the other co-migrating with the fractions containing alpha 1(V), alpha 2(V), and alpha 3(V) chains in a 1:1:1 ratio. Electrophoresis in a second dimension under denaturing conditions confirmed that the fast-migrating band contained (alpha 1(V]2 alpha 2(V) and that the slow-migrating band contained the three chains in equimolar ratio. CD spectra of the two fractions and resistance to trypsin-chymotrypsin digestion confirmed that the two fractions contain triple helical collagen. Thermal denaturations were monitored by the changes in CD signal at 221 nm. The two fractions purified by ammonium sulfate precipitation melted at 39.1 and 36.4 degrees C for the (alpha 1(V]2 alpha 2(V) and alpha 1(V) alpha 2(V) alpha 3(V) fractions, respectively. Trypsin cleavage of these two native fractions at temperatures near melting produced completely different fragmentation patterns, indicating different partial unwinding sites of the alpha 1(V) and alpha 2(V) chains in the two preparations and thus different molecular assemblies. Our data demonstrate the existence of two different molecular assemblies of type V collagen in human placenta consisting of (alpha 1(V]2 alpha 2(V) and alpha 1(V) alpha 2(V) alpha 3(V) heterotrimers.
Acetates↗
Isolation and characterization of pepsin-solubilized human basement membrane (type IV) collagen peptides.
Native type IV collagen was isolated from human placental tissue by pepsin digestion, fractional salt precipitation, reduction and alkylation, a second pepsin digestion, and chromatography on diethylaminoethyl- and carboxymethyl-cellulose. After denaturation, 10 distinct peptides were isolated from this material by molecular sieve, ion-exchange, and high-performance liquid chromatography. All of the peptides were found to have amino acid compositions characteristic of type IV collagen. Analysis of the eight major peptides by amino-terminal amino acid sequencing and by cyanogen bromide and tryptic peptide mapping has revealed the manner in which they are derived from type IV collagen. Pepsin liberates two large peptides by attacking non-triple-helical regions, one derived from the alpha 1 (IV) chain (F2, Mr 90 000) and one derived from the alpha 2 (IV) chain (F3, Mr 75 000). The alpha 1 (IV)-derived F2 peptide is also represented in the pepsin digest by amino-terminal and carboxy-terminal subfragments [F4c (Mr 41 000) and F4a (Mr 60 000)], as is the alpha 2 (IV)-derived F3 peptide [F5 (Mr 28 000) and F4b (Mr 50 000), respectively]. These findings indicate that the molecular regions from which the larger peptides are derived in themselves contain pepsin-sensitive (non-triple-helical) domains. In addition, several of the peptides examined were found to be present in two slightly different forms, suggesting that closely adjacent pepsin-sensitive sites often exist within the type IV collagen molecules. The methods outlined here provide a reliable means by which identifiable type IV collagen peptides can be isolated.(ABSTRACT TRUNCATED AT 250 WORDS)
Amino Acid Sequence↗
Biochemical and morphologic studies of cartilage from the adult human sacroiliac joint.
The cartilage of the adult sacroiliac joint contains type II collagen and a high concentration of glycosaminoglycan. Furthermore, large aggregating proteoglycans and link proteins were extracted from the sacral cartilage. In these respects the sacroiliac cartilage is similar to that in the peripheral joints. However, while the organization of the collagen in the sacral cartilage is typical of an articular cartilage, the organization of the ilial cartilage is very different, and throughout its depth it possesses narrow collagen fibrils arranged parallel to the articular surface.
Adult↗
Congenital primary cutaneous osteoma: biochemical and histological studies.
Biopsies of a cutaneous osteoma and of normal-looking skin from a 1-year-old girl were studied for histological appearance and collagen biochemistry. The mineralized tissue contained a matrix similar to bone: Only type I collagen, with a hydroxylysine content (0.48%) higher than in the skin (0.35%) and dihydroxylysinonorleucine as the major reducible crosslink. As expected, the normal skin adjacent to the lesions contained type I and type III collagen and as major crosslinks hydroxylysinonorleucine and histidinohydroxymerodesmosine. Histological studies showed the presence of woven bone with very little trabeculation. Numerous active osteoblasts were laying down a rapidly calcified non-lamellar matrix. Osteocytes and multinucleated osteoclasts were also noted. The study demonstrates the osseous nature of the lesion and suggests that an abnormal cell differentiation is associated with this form of osteoma.
Bone and Bones↗
Osteoblasts isolated from mouse calvaria initiate matrix mineralization in culture.
A method is presented for isolating osteoblasts from newborn mouse calvaria without the use of digestive enzymes. The procedure is based on the ability of osteoblasts to migrate from bone onto small glass fragments (Jones, S.J., and A. Boyde, 1977, Cell Tissue Res., 184:179-193). The isolated cells were cultured for up to 14 d in Dulbecco's modified Eagle's medium supplemented with 10% fetal calf serum and 50 micrograms/ml of ascorbic acid. 7-d cultures were incubated for 24 h with [3H]proline. High levels of collagen synthesis relative to total protein were found, as measured by collagenase digestion of medium and cell layer proteins. Analysis of pepsin-digested proteins from the same cultures by SDS PAGE showed that type I collagen was predominantly produced with small amounts of type III and V (alpha 1 chains) collagens. Osteoblasts grown in the presence of beta-glycerophosphate were able to initiate mineral deposition in culture. Electron microscopic analysis of the cultures revealed the presence of needle-shaped apatite-like crystals associated with collagen fibrils and vesicles in the extracellular space. Mouse skin fibroblasts cultured under identical conditions failed to initiate mineralization. Electron histochemical studies revealed the presence of alkaline phosphatase activity, associated with osteoblast membranes, matrix vesicles and on or near collagen fibrils. Thus these isolated osteoblasts retained in culture their unique property of initiating mineralization and therefore represent a model of value for studying the mineralization process in vitro.
Animals↗
A comprehensive approach to the study of collagen primary structure based on high-performance liquid chromatography.
A comprehensive approach for the structural microanalysis of collagen based of collagen based on high-performance liquid chromatography (h.p.l.c.) has been developed using calf skin type I collagen as a model system. The alpha, beta and gamma components were separated, after heat denaturation, on a TSK 4000 SW gel permeation column, using a nonvolatile buffer. Monitoring at 210 nm permits the detection of 1 microgram of a single chain. The alpha 1(I) and alpha 2(I) chains were completely resolved using a large-pore reversed-phase column (Vydac 201 TP 4.6) eluted by an aqueous acetonitrile gradient (24-48%) containing 0.01 M heptafluorabutyric acid as an ion-pairing agent. The purified alpha 1(I) chain was digested with CNBr and the resulting fragments separated in the same chromatography system with a gradient containing a 12.8-44.8% acetonitrile gradient. The purified alpha 1(I)CB 3 peptide was further cleaved with trypsin and the resulting peptides separated first by a similar chromatography with a 4-32% acetonitrile gradient. Resolution of some poorly separated peptides was obtained by a rechromatography using trifluoroacetic acid as counterion. The isolated peptides were hydrolyzed and identified by their amino-acid composition. Sequencing of h.p.l.c.-purified alpha 1(I)CB 3 was also performed to demonstrate the suitability of the technique for the preparation of peptides for amino-acid sequencing. This study demonstrates that detailed structural analysis can be performed on 3 mg of a purified collagen.
Amino Acid Sequence↗
Stimulation of collagenase secretion from rheumatoid synovial tissue by human collagen peptides.
Dayer et al. demonstrated that mononuclear cells from human peripheral blood produce a mononuclear-cell factor that stimulates collagenase secretion from adherent rheumatoid synovial cells. The production of this mononuclear-cell factor can be stimulated by phytohemagglutinin, a T-cell mitogen. We have examined immune mechanisms by which collagenase secretion may be stimulated from explants of rheumatoid synovial tissue and from primary monolayer cultures of rheumatoid synovial cells. Conditioned media from cultures of normal peripheral-blood mononuclear cells that had been activated by phytohemagglutinin stimulated collagenase secretion from most explants and from all monolayer cultures that were examined. The direct addition of phytohemagglutinin stimulated collagenase secretion in explants from eight of fourteen patients and in monolayer cultures from three of six patients. These observations indicate the presence of responsive T lymphocytes in rheumatoid synovial tissue and implicate them in the stimulation of collagenase secretion from synovial cells. The direct addition of type-II collagen peptides to rheumatoid explants also stimulated collagenase secretion in explants from six to fifteen patients. Four of five of these patients displayed moderate or severe disease activity. Other patients showed a marginal stimulation of collagenase secretion on addition of type-II collagen peptides (four of fifteen patients) and type-I collagen peptides (three of twelve patients). None of the patients with mild or inactive disease responded to type-II collagen. With one exception, the addition of collagen peptides to monolayer cultures did not stimulate collagenase secretion. An increased production of factors that enhance or inhibit the migration of polymorphonuclear leukocytes was also observed in explant cultures in response to the addition of phytohemagglutinin (in seven of twelve patients), of type-I collagen peptides (in five of ten patients), and of type-II collagen peptides (in five of eleven patients). There was no correlation between production of these factors and stimulation of collagenase secretion in rheumatoid synovial tissue.
Arthritis, Rheumatoid↗
Analysis of the type of collagen present in osteoarthritic human cartilage.
Abnormal synthesis of type I collagen by fibrocartilage has been suggested as a mechanism involved in degenerative arthritis. Samples of normal and osteoarthritic adult femoral head cartilage were thus studied for histology and collagen composition. The electrophoretic analysis of the cyanogen bromide-derived peptides showed the sole presence of type II collagen in all normal and in all osteoarthritic samples, except those in which fibrocartilage was present. The sensitivity of the technique would not permit, however, the detection of a minute amount (less than 3%) of type I collagen in the samples. The results show that massive deposition of type I collagen occurs only when fibrocartilage is formed. It is suggested that this fibrocartilage is formed when the subchondral bone is damaged.
Aged↗
The collagen crosslinking in the hypophosphatemic male mouse.
In order to evaluate the influence of bone mineralization on collagen metabolism, the bone collagen crosslinks were determined in femur diaphyses of mice with X-linked hypophosphatemia and of control littermates. No quantitative difference could be elicited between the two groups. It was also noted that in the mouse, cortical bone maturation is accompanied by a slight increase in the number of reducible crosslinks.
Animals↗
Separation of collagen cyanogen bromide-derived peptides by reversed-phase high-performance liquid chromatography.
A new technique for separation of the CNBr cleavage products of collagen is described. It involves the use of a 30 nm pore reversed-phase high-performance liquid chromatography column eluted with a linear gradient of acetonitrile/water containing 0.01 M-heptafluorobutyric acid. The separation of type I, type II and type III CNBr peptides is described. Resolution is particularly good for the low-molecular-weight peptides. The method is fast, quantitative and sensitive, and the complete volatility of the eluent facilitates the recovery of the separated peptides.
Acetonitriles↗
Collagen changes in the human uterine cervix at parturition.
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Acetates↗
An immunological and electrophoretic study of Rhodospirillum rubrum chromatophore fragments.
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Animals↗
Collagens as multidomain proteins.
The number of proteins known to contain collagen-like triple helical domains is rapidly increasing. The functions of these domains are to provide molecular rods that separate spatially non-triple helical domains with varied properties and structures and to permit lateral interactions between molecules. Two-thirds of the amino acids of the triple helical domains have their side-chains at the surface of the protein. The triple helix is also a structure that is easily predictable from the primary structure. The structure of several recently discovered collagens are discussed in terms of domains and functions. The triple helical domains have sizes varying from 33 to over 1,000 amino acid residues. The longest uninterrupted triple helices are involved in the formation of the classical quarter-staggered fibrils. Other triple helical domains permit varied molecular aggregates. A very broad spectrum of non-triple helical or globular domains are interspersed by triple helices. Only those located at the extremities of the molecules are large in size, sometimes several hundred kDa, while the domains separating 2 triple helices are small (less than 50 amino acids) and provide the molecules with hinges, proteolytic cleavage sites or other specialized functions like a glycosaminoglycan attachment site. If the assembly of the 3 chains required for the triple helix formation can be controlled in vitro, collagen-like molecules offer an as yet unexploited potential for protein engineering.
Animals↗
Osteogenesis imperfecta: comparison of molecular defects with bone histological changes.
Osteogenesis imperfecta (OI) is a group of inherited disorders characterized by a predisposition to bone fracturing, and usually resulting from mutations in the genes encoding type I collagen. This report describes the molecular defects in a patient with type II OI and another with type III OI. These patients were demonstrated to possess point mutations resulting in glycine-->arginine substitutions within the triple helical domain of the alpha 1(I) or alpha 2(I) collagen polypeptide chain. The defect in the type II OI patient affected residue 211 of the alpha 1(I) triple helical domain, and constitutes the most amino-terminal lethal glycine-->arginine substitution described to date. The substitution in the type III OI patient affected residue 427 of the alpha 2(I) triple helical domain. Both defects were informative in that they identified the regions of the alpha 1(I) and alpha 2(I) collagen chains in which the phenotypes associated with glycine-->arginine substitutions undergo a transition between lethal and nonlethal forms, thereby allowing a more reliable prognosis of disease severity. The histological examination of bone from these patients revealed striking abnormalities in the quantity and organization of mineralized bone structures, compared with age-matched controls. Although the patients were differently classified, no major differences in the magnitude of bone architectural changes could be perceived, consistent with the presence of their defects near a common phenotypic transition. The results are compatible with there being a gradient in severity between OI types II and III, and that parameters external to the gene mutations might account for the survival differences in the 2 cases presented in this study.
Base Sequence↗