Structures of the extracellular matrix

Schuppan, D. Structure of the extracellular matrix in normal and fibrotic liver collagens and glycoproteins. Semin. Liver Dis. 1990 10 1-10... 

It is generally agreed that in order to succeed in repairing tissue, the scaffold should not only be receptive to cells but should also mimic the structure of the extracellular matrix (ECM) of the body. Accordingly, it should be composed of nano-sized fibers with fine pores and a three-dimensional... 

Schiller, J. and Huster, D. 2012. New methods to study the composition and structure of the extracellular matrix in natural and bioengineered tissues. Biomatter, 2 115-131. 

The extracellular matrix is an area of biopolymer self-assembly and these are exported to the extracellular space by fibroblasts or the cells of this family (chondroblasts in cartilage and osteoblasts in bone tissue). The molecular structure of the extracellular matrix is... 

Hyaluronic acid is a linear polysaccharide found in the highest concentrations in soft connective tissues where it fills an important structural role in the organization of the extracellular matrix (23,24). It has been used in ophthalmic preparations to enhance ocular absorption of timolol, a beta blocker used for the treatment of glaucoma (25), and in a viscoelastic tear formulation for conjunctivitis (26). The covalent binding of adriamycin and daunomycin to sodium hy-aluronate to produce water-soluble conjugates was recently reported (27). 

The first elastomeric protein is elastin, this structural protein is one of the main components of the extracellular matrix, which provides stmctural integrity to the tissues and organs of the body. This highly crosslinked and therefore insoluble protein is the essential element of elastic fibers, which induce elasticity to tissue of lung, skin, and arteries. In these fibers, elastin forms the internal core, which is interspersed with microfibrils [1,2]. Not only this biopolymer but also its precursor material, tropoelastin, have inspired materials scientists for many years. The most interesting characteristic of the precursor is its ability to self-assemble under physiological conditions, thereby demonstrating a lower critical solution temperature (LCST) behavior. This specific property has led to the development of a new class of synthetic polypeptides that mimic elastin in its composition and are therefore also known as elastin-like polypeptides (ELPs). 

J. Engel, Common structural motifs in proteins of the extracellular matrix, Curr. Opin. Struct. Biol., 3 (1991) 779-785. 

As constituents of proteoglycans (see p.346), the glycosaminoglycans—a group of acidic heteropolysaccharides—are important structural elements of the extracellular matrix. 

Collagens are quantitatively the most abundant of animal proteins, representing 25% of the total. They form insoluble tensile fibers that occur as structural elements of the extracellular matrix and connective tissue throughout the body. Their name (which literally means glue-producers ) is derived from the gelatins that appear as a decomposition product when collagen is boiled. 

Nature often uses cystine knots of variable complexity to assemble polypeptide chains in the correct order and to stabilize the structure of the resulting proteins. Classical examples are proteins of the extracellular matrix with collagens and gelatines as the main components. This simple cystine-knot approach has been applied to synthetic constructs to ligate in a desired order helix bundles. [166 170 194-1%] It has also been used to mimic natural multiple-chain containing proteins like collagen.[83 1691971... 

In addition to the many receptors that act as protein Tyr kinases, a number of receptorlike plasma membrane proteins have protein Tyr phosphatase activity. Based on the structures of these proteins, we can surmise that their ligands are components of the extracellular matrix or the... 

Compounds of type 107 were evaluated as MMP inhibitors <1999JME4547>. MMPs are a structurally related class of enzymes that is responsible for the metabolism of the extracellular matrix proteins and are linked to diseases such as arthritis and multiple sclerosis. 

The surface of the fibril provides the interface between the internal structural and mechanical properties of a fibril, and the rest of the extracellular matrix. The surface, therefore, is the most complex area of the fibril in terms of molecular heterogeneity and structure. Caution has to be taken in the comparison of structural and biochemical evidence from complementary techniques since the extraction, dehydration, and sample preparation can cause variation in observations of fibril surface properties (Raspanti et at, 1996). 

Katz BZ, Zamir E, Bershadsky A et al (2000) Physical state of the extracellular matrix regulates the structure and molecular composition of cell-matrix adhesions. Mol Biol Cell 11(3) 1047-1060... 

P. Dandekar. I. AggeJer. and P. Talbot. Structure, distribution and composition of the extracellular matrix of human oocytes and cumulus masses. Bum. Rep rod. 7 391 (1992). 

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