Three-dimensional structures tissue factor

Figure 12-18 A ribbon drawing of the three-dimensional structure of the extracellular region (residues 3 to 213) of human tissue factor. Strands of domain 1 and 2 are labeled A to G. Two helices are labeled aj, and and the three asparagines that provide the glycosylation sites are also marked. MolScript drawing from Harlos et al. ...

Also see color figure.) Tissue factor-factor Vila complex. The three-dimensional structure of the complex of factor Vila and tissue factor (minus the transmembrane polypeptide domain of the tissue factor) in the absence of membrane surface. It is approximately 115 A in length and has a diameter of 40-50 A. Factor Vila shows its four distinct domains the Gla domain, two EGF-like domains, and the proteinase domain. Tissue factor contacts factor VHa via the interface between the two fibronectin type Ill-like domains. All four domains of factor Vila appear to be involved in the interaction between tissue factor and factor Vila. The Gla domain of factor Vila is folded very similarly to the Gla domain of prothrombin (Gla domain of prothrombin fragment 1). Activation of factor VII can be catalyzed by thrombin, factor Xa, factor Vila, and factor Xlla—all by cleavage at Arg -Ile . Secondary structures are shown in the center diagram two views of the close interactions between TF and factor Vila are shown in the two diagrams at each side. 

The three-dimensional structures of approximately 30 complexes between antibodies and various protein antigens have been determined in recent years, including hen egg white lysozyme (HEL) (Amit et al., 1986 Sheriff ct a/., 1987 Padlaneta/., 1989 Chitarra et a/., 1993 Braden eta/., 1994 Rondo et al., 1999 Li et al., 2000), influenza virus neuraminidase (Colman et al., 1987 Tuhp et al., 1992 Malby et al., 1994), horse cytochrome c (Mylvaganam et al., 1998), human tissue factor (Huang et al.,... 

Elastin is the second most common structural component in the ECM, second only to the family of collagens [67]. It is the major component of the elastic matrix in mammalian tissues, which provides the mechanical properties and elasticity to the matrix [68,69]. In the succeeding text, we discuss some critical factors in the choice and application of elastin as a biomaterial including synthesis and production of elastin, biomechanical and biochemical roles of elastin, and current technologies for three-dimensional (3D) matrices produced using elastin. 

Cells are often implanted or seeded into an artificial structure capable of supporting three-dimensional tissue formation. These structures, typically called scaffolds, are often critical, both ex vivo as well as in vivo, to recapitulating the in vivo milieu and allowing cells to influence their own microenvironments. Scaffolds usually serve at least one of the following purposes (i) allow cell attachment and migration, (ii) deliver and retain cells and biochemical factors, (iii) enable diffusion of vital cell nutrients and expressed products, and (iv) exert certain mechanical and biological influences to modify the behavior of the cell phase. 

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