The distribution of collagen XI in fibril fragments from 17-d chick embryo sternal cartilage was determined by immunoelectron microscopy using specific polyclonal antibodies. protein distributed throughout the but antigenically masked due to tight packing molecules and could be identified only at sites where structure partially disrupted. Collagens II IX were also uniformly along fibrils but, contrast XI, accessible antibodies intact fibrils. Therefore, are heterotypically assembled...

The role of endogenous inducers inflammation is poorly understood. To produce the proinflammatory master cytokine interleukin (IL)-1beta, macrophages need double stimulation with ligands to both Toll-like receptors (TLRs) for IL-1beta gene transcription and nucleotide-binding oligomerization domain-like activation inflammasome. It particularly intriguing define how this complex regulation mediated in absence an infectious trigger. Biglycan, a ubiquitous leucine-rich repeat proteoglycan...

It has recently become apparent that collagen fibrils may be composed of more than one kind macromolecule. To explore this possibility, we developed a procedure to purify fibril fragments from 17-d embryonic chicken sternal cartilage. The population obtained shows, after negative staining, uniformity in the banding pattern and diameter similar situ. Pepsin digestion preparation releases types II, IX, XI proportion 8:1:1. Rotary shadowing reveals d-periodic distribution 35-40-nm long...

The EHS sarcoma (named after its discoverer, Engelbreth‐Holm, and primary characterizer, R. Swarm) contains an extracellular matrix of basement membrane. collagenous component the membrane was extracted with dilute acetic acid from tumors grown in lathyritic mice separated other proteins by chromatographic methods. This collagen has a composition resembling that reported for collagens. polypeptide chains tumor are linked disulfide bonds migrate reduction intermediate between α und β...

Peptidyl-prolyl cis-trans-isomerase accelerates otherwise slow, rate-limiting isomerization steps during folding of proteins in vitro, but is not yet securely identified with any specific physiologic role. and the cyclosporin A (CsA)-binding protein cyclophilin are identical, peptidyl-prolyl activity inhibited by immunosuppressive drug CsA vitro. To establish a possible role cis-trans-isomerase, we have studied procollagen I suspended chick embryo tendon fibroblasts. Folding slowed CsA: time...

The kinetics of triple‐helix formation in type III pN‐collagen, collagen and a quarter fragment was followed by optical rotation circular dichroism. Kinetic intermediates were detected trypsin digestion polyacrylamide gel electrophoresis. end products refolding at 25°C identical to the native molecules according their melting profiles, molecular weights sedimentation behavior. Only low temperatures (4–15°C) mismatched structures lower stability formed. At helix started exclusively set three...

Fibrils of embryonic cartilage are heterotypic alloys formed by collagens II, IX, and XI have a uniform diameter ∼20 nm. The molecular basis this lateral growth control is poorly understood. Collagen II subjected to fibril formation <i>in vitro</i> produced short tapered tactoids with strong D-periodic banding. maximal width these varied over broad range. By contrast, authentic mixtures yielded long weakly banded fibrils, which, strikingly, had about 20 same was true for lacking collagen IX...

Here we describe a novel specific component of tissue junctions, collagen XXII. It was first identified by screening an EST data base and subsequently expressed as recombinant protein characterized authentic component. The COL22A1 gene on human chromosome 8q24.2 encodes that structurally belongs to the FACIT family (fibril-associated collagens with interrupted triple helices). Collagen XXII exhibits striking restricted localization at junctions such myotendinous junction in skeletal heart...

We studied tissue and cultured skin fibroblasts from a newborn with the lethal perinatal form of osteogenesis imperfecta born to mother Marfan syndrome her unrelated husband. Dermis infant was thinner fibril diameter smaller than control; dermal fibroblastic cells had dilated endoplasmic reticulum. His in culture synthesized two different species pro alpha 1(I) chains about equal quantity. One chain normal, other contained cysteine within triple-helical portion COOH-terminal cyanogen bromide...

The tissue distribution of type II and IX collagen in 17-d-old chicken embryo was studied by immunofluorescence using polyclonal antibodies against a peptic fragment (HMW), respectively. Both proteins were found only cartilage where they co-distributed. They occurred uniformly throughout the extracellular matrix, i.e., without distinction between pericellular, territorial, interterritorial matrices. Tissues that undergo endochondral bone formation contained collagen, whereas periosteal...

Decorin is a multifunctional small leucine‐rich proteoglycan involved in the regulation of collagen fibrillogenesis. In patients with variant Ehlers–Danlos syndrome, about half secreted decorin lacks single glycosaminoglycan side chain. Notably, these have skin‐fragility phenotype that resembles null mice. this study, we investigated role glycanated and unglycanated on Glycosaminoglycan‐free decorin, generated by mutating Ser4 mature protein core into Ala (DCN‐S4A), showed reduced inhibition...

Abstract The collagen-like portion of a peptide which comprises the amino-terminal precursor-specific region bovine type III procollagen, showed an unusually fast, concentration independent and fully reversible triple helix ⇄ coil transition. A set three interchain disulfide bridges probably provides effective nucleus for formation. Refolding occurred in two kinetic phases. first one was not resolved (half time < 5 s) second had half about 90 s at 20 °C. When measurements were performed...

Cartilage matrix is a composite of discrete, but interacting suprastructures, i.e. cartilage fibers with microfibrillar or network-like aggregates and penetrating extrafibrillar proteoglycan matrix. The biomechanical function the collagen are to absorb compressive tensional loads, respectively. Here, we focusing on suprastructural organization fibrils degradation process their hierarchical organized fiber architecture studied at high resolution authentic location within cartilage. We present...

In bone forming cartilage in vivo, cells undergo terminal differentiation, whereas most of the normal articular do not. Chondrocyte hypertrophy can be induced also vitro by diffusible signals. We have identified growth factors or hormones acting individually on 17-d chick embryo sternal chondrocytes cultured agarose gels under strictly serum-free conditions. Insulin-like factor I insulin triggered first steps chondrocyte maturation, i.e., cell proliferation and increased matrix deposition...

Primary chondrocytes from whole chick embryo sterna can be maintained in suspension culture stabilized with agarose for extended periods of time. In the absence FBS, cells remain viable only when seeded at high densities. They do not proliferate a rate but they deposit extracellular matrix fibrils resembling those authentic embryonic cartilage their appearance and collagen composition. The exhibit many morphological biochemical characteristics resting produce X, marker hypertrophic...

The matrilins are a family of four noncollagenous oligomeric extracellular matrix proteins with modular structure. Matrilins can act as adapters which bridge different macromolecular networks. We therefore investigated the effect collagen IX deficiency on matrilin-3 integration into cartilage tissues. Mice harboring deleted Col9a1 gene lack synthesis functional protein and produce fibrils completely devoid IX. Newborn knockout mice exhibited significantly decreased (COMP) signals,...