Structural and immunological characterization of type IV collagen isolated from chicken tissues.

Previously, a type IV collagen fraction was isolated from chicken gizzard and further fractionated into three components called F1, F2 and F3 [Mayne, R. and Zettergren, J.G.

The isolation and partial characterization of chondronectin, an attachment factor for chondrocytes.

We have previously demonstrated that the adhesion of embryonic chick sternal chondrocytes to a type II-collagen substrate is not mediated by fibronectin but rather by a distinct attachment factor which we have named chondronectin. Here we describe the isolation, properties, and biological activity of chondronectin prepared from chicken serum. Chondronectin is shown to be a glycoprotein with an estimated Mr = 180,000.

Rates of synthesis of basement membrane proteins by differentiating teratocarcinoma stem cells and their modulation by hormones.

The embryonal carcinoma mouse cell line F-9 was used as a convenient model for a quantitative study of the production of the basement membrane proteins laminin and type IV collagen. Both proteins could be identified in the culture medium and cell layer by radioimmuno assays, metabolic labeling and immunofluorescence. More than 95% of the material is secreted into the medium.

Extracellular matrix formation by chondrocytes in monolayer culture.

In previous studies were have reported on the secretion and extracellular deposition of type II collagen and fibronectin (Dessau et al., 1978, J. Cell Biol.

Immunofluorescence analysis of collagen, fibronectin, and basement membrane protein in scleroderma skin.

Scleroderma skin and the subcutaneous tissue was studied by indirect immunofluorescence with specific antibodies against interstitial collagens and procollagens, against fibronectin and against the basement membrane proteins Type IV collagen and laminin. Staining for Type I procollagen and fibronectin was distinctly increased in the lower dermis and subcutaneous tissue. When compared with normal skin the data suggests that fibrosis may start around capillaries and in close proximity to adipose cells.

Changes in the patterns of collagens and fibronectin during limb-bud chondrogenesis.

The distribution and sequence of appearance of fibronectin and of type-I and type-II collagen in the developing cartilage models of embryonic chick hind-limb buds was studied by immunofluorescence, using specific antibodies directed against these proteins. Fibronectin and type-I collagen are evenly distributed throughout the intercellular space of the mesenchyme prior to condensation of core mesenchyme of the limb anlage and formation of the cartilage blastema. With the onset of the condensation process fibronectin and type-I collagen appear to increase in the cartilage blastema compared to the surrounding loose mesenchyme, reaching a maximal density at the time of cartilage differentiation.

Synthesis of types I, III and AB2 collagen by chick tendon fibroblasts in vitro.

Tendons from 14--17-day-old chick embryos contain predominantly type I collagen and about 5% AB2 collagen; type III collagen is not detectable by biochemical methods, such as sodium dodecyl sulfate/polyacrylamide gel electrophoresis or cyanogen bromide pattern, but can be visualized by immunofluorescence staining with collagen-type-specific antibodies. Similarly, freshly dissociated tendon cells secrete only type I collagen into the culture medium but no significant amounts of type III collagen [Uitto, J., Lichtenstein, J.

Synthesis of type III collagen by fibroblasts from the embryonic chick cornea.

Synthesis of collagen types I, II, III, and IV in cells from the embryonic chick cornea was studied using specific antibodies and immunofluorescence. Synthesis of radioactively labeled collagen types I and III was followed by fluorographic detection of cyanogen bromide peptides on polyacrylamide slab gels and by carboxymethylcellulose chromatography followed by disc gel electrophoresis. Type III collagen had been detected previously by indirect immunofluorescence in the corneal epithelial cells at Hamburger-Hamilton stages 20--30 but not in the stroma at any age.

Biochemical and immunological studies of fibroblasts derived from a patient with Ehlers-Danlos syndrome type IV. Demonstrate reduced type III collagen synthesis.

Fibroblasts derived from a skin biopsy of a patient with the Ehlers-Danlos syndrome (EDS) type IV were cultured in monolayer. The amount of collagen synthesized during a 24-h pulse was not different from that found with normal fibroblasts. Chromatographic procedures and immunofluorescence staining showed a normal synthesis of type I procollagen and collagen but a deficiency in synthesis of type III procollagen and collagen.

Synthesis and extracellular deposition of fibronectin in chondrocyte cultures. Response to the removal of extracellular cartilage matrix.

Fibronectin, the major cell surface glycoprotein of fibroblasts, is absent from differentiated cartilage matrix and chondrocytes in situ. However, dissociation of embryonic chick sternal cartilage with collagenase and trypsin, followed by inoculation in vitro reinitiates fibronectin synthesis by chondrocytes. Immunofluorescence microscopy with antibodies prepared against plasma fibronectin (cold insoluble globulin [CIG]) reveals fibronectin associated with the chondrocyte surface.

Similarity of antigelatin factor and cold insoluble globulin.

Antigelatin factor, a protein capable of complexing denatured collagen, was separated from human serum by adsorption onto immobilized collagen. Antiserum raised against the material binding to denatured collagen permitted the development of a radioassay for the determination of antigelatin factor in which the complex of antigelatin factor and denatured 125I-labeled collagen is precipitated with this antiserum. Further purification of antigelatin factor was achieved by chromatography on DEAE-cellulose yielding an electrophoretically homogeneous protein.

[Characterization of a serum protein with selective affinity for denatured collagen (author's transl)].

A protein known as antigelatin factor (AGF) was isolated from human serum by affinity chromatography with immobilized denatured collagen. In biochemical and immunological assays AGF showed specificity to denatured, but not to native collagen of the types I, II and III. A close relationship to Cell Attachment Protein and Cold Insoluble Globulin was found in comparative studies.

Identification of the sites in collagen alpha-chains that bind serum anti-gelatin factor (cold-insoluble globulin).

Anti-gelatin factor was prepared from guinea-pig and human serum by affinity chromatography on denatured type-I collagen. As shown previously, this component is related to cold-insoluble globulin. It reacted with 125I-labelled denatured collagen, and the reaction could be inhibited by preincubation with unlabelled collagenous components.

On the mechanism and stereochemistry of the malate-lactate fermentation of Leuconostoc mesenteroides.

During the transformation of (2S, 3R) [3-3H]malate to (S) lactate no tritium exchange takes place. The stereochemical course of the decarboxylation studied with (2S, 3R) [3-2H]-malate in 3HOH/H2O and (2S, 3R) [3-3H]malate in 2H2O occurs with retention and is therefore the same as that determined by other authors for malic enzyme from vertebrates and from Escherichia coli. The malate-lactate fermentation is a useful procedure to prepare chiral methyl groups on a preparative scale starting from (2S, 3R) [3-H]malate.