Ligamentum nuchae

Average wing-hinge Prealar arm Collagen (oxhide) Elastin (ox ligamentum nuchae) Silk fibroin Bombyx mori)... 

Postmortem findings include edema in the periorbital tissue, neck muscles, ligamentum nuchae, intermuscular and lungs hemorrhage of the tongue, intestinal serosa, kidneys, and pericardium and general subcutaneous edema and hemorrhage. 

In a more recent paper [160], Urry et al. reported that x20-poly (GGAP) was nonadhesive to both bovine ligamentum nuchae fibroblast and human umbilical vein endothelial cells (HUVECs), even in the presence of serum. Urry et al. interpreted this behavior in terms of their hydrophobicity scale. They suggested that x20-poly[50(GGAP), (GRGDSP)], for example, could provide the inner lamina for a vascular prosthesis. 

The DS.GAG chain in calf ligamentum nuchae is attached to a L-lysine residue in the protein core. 2 In adult human skin, the DS.GAG chain is linked by a D-xylosyl-L-alanine bond involving the C-terminus carboxyl group of L-alanine.13... 

Wallace, R. N., Streeten, B. W., and Hanna, R. B. (1991)). Rotary shadowing of elastic system microfibrils in the ocular zonule, vitreous, and ligamentum nuchae. Curr. Eye Res. 10, 99-109. 

CONCENTRATIONS OF CROSSLINKS AND LYSINE RESIDUES IN ELASTIN ISOLATED FROM THE LIGAMENTUM NUCHAE OF CATTLE OF INCREASING AGEa... 

The most ready source of elastin of high purity is the ligamentum nuchae of the larger ruminants, and from this source a protein of constant composition can be isolated by a variety of methods depending on the solubilization and removal of other less inert tissue components. Because of the ease with which it may be isolated the elastin of bovine ligamentum nuchae has come to be regarded as the type standard, but it is by no means certain that elastins from other mammals or other tissues in the same mammal are of identical constitution. 

The form in which elastin is laid down varies considerably in the different types of elastic tissue. Membranes with a very high elastin content are found in the walls of the larger arteries, in some parts of the heart, and in the trachea and bronchi. In the larger arteries the structural units of the elastic tissue formation are concentric lamellae which are often of rather variable thickness and always contain many irregular openings. In the ligamentum nuchae of some animals, particularly the ox, the structure is quite different and thick longitudinal elastic fibers, of almost circular cross section, form most of the tissue. 

Probably because of the ease with which they can be prepared, purified fiber preparations from bovine ligamentum nuchae have formed the starting point of most chemical investigations of elastin. These preparations how-... 

Samples of elastic fibers in various stages of elastase treatment were examined with the electron microscope. Intact elastic fibers, because of their considerable thickness, appeared as opaque cylinders with smooth walls. The surfaces at the broken ends were smooth and sharply angular. The largest elastic fibrils that could be effectively penetrated by the electron beam were 1 /x in diameter and corresponded to the fibrils described above as making up one-fourth of the whole elastic fiber of ligamentum nuchae. These fibrils appeared as fairly smooth cylinders with slightly convoluted walls, which sometimes bifurcated into two smaller fibrils or threw out still smaller fibrils sometimes in the form of loops. 

Fig. 2. Electron micrograph showing the fibrillar structure of an elastic fiber from bovine ligamentum nuchae. (Gotte and Serafini-Fracassini, 1962.) The elastin fibers were treated with dilute sodium hydroxide at 98°C for 1 hr, washed with hot water, and disintegrated ultrasonically at 40 kc. The magnification is 63,000X and the individual fibrils are 10 2 The specimen was shadowed with chromium at 20 degrees.

They form a network of long, fine elementary fibrils about 10 m/x in diameter which seem to be almost as strongly adherent in the lateral direction as they are along the fiber axis. Partial digestion with elastase or ultrasonic treatment reveals systems of interconnected fibrils which are tangled and loosely twisted together to form dense cordlike fibers in ligamentum nuchae or thick membranes in arterial walls. 

Products similar in amino acid composition may be prepared from Kgamentum nuchae by a number of other methods which involve the use of acidic or alkaline reagents. Thus Lansing et al. (1952) following Lowry et al. (1941) digested the dried, defatted tissue from the ligamentum nuchae of horses and the tunica media of fresh human aortas with 0.1 V NaOH at 95 C and took small samples at. 5-min time intervals for histological and... 

Paper chromatography was used hy Bowes and Kenten (1949) to examine the amino acid composition of elastin preparations from ligamentum nuchae and skin. The results indicated either that the elastic fibers of skin differ from those of ligamentum nvchac in amino acid composition or that they are less resistant to hot water. This interesting suggestion does not appear to have been pursued. 

Fig. 3. Time-course of solubilization of elastin from three bovine tissues (Golte et al., 1962). The elastin samples (prepared by autoclaving) were suspended in 0.5 N NaOH and maintained at 25°C with gentle rocking. The amino acid composition of the samples is given in Table I. Key O = elastin from bovine ear cartilage A elastin from bovine aorta X = elastin from bovine ligamentum nuchae.

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