Collagen protein

Paleodiet studies have focused on the analysis of collagen, due to its ability to survive in ancient bone. Like all proteins, collagen is composed of amino acid (AA) units present in relatively constant proportions characteristic of the specific protein. The isotopic composition of a sample of collagen is the weighted average of the 5 C values of each of the constituent amino acids. 

The major components of the ECM are the structural proteins collagen, elastin, and fibrihin a number of specialized proteins (eg, fibronectin and laminin) and various proteoglycans. 

The protein collagen undergoes hydrolytic degradation to gelatin in a manner which indicates the presence of a small minority of comparatively easily hydrolyzable bonds. Scatchard, Oncley, Williams, and Brown concluded that these are regularly spaced at intervals of about 1200 units in the collagen molecule. 

Phosphate is of enormous importance for the chemistry of bone. The basic structure of bone is provided by hydroxyapatite,Ca5(P04)30H, and a protein, collagen. As indicated by the formula, each molecule of hydroxyapatite contains... 

So what does this magical molecule do Actually, it does two things, one rather more crystalline clear than the other. The crystal clear thing that ascorbic acid does is act as coenzyme for an enzyme known as prolyl hydroxylase. This enzyme catalyzes the conversion of the amino acid proline to hydroxyproline, a major, if exotic, amino acid in the structural protein collagen ... 

The pleural tissue is a typical connective tissue that consists mostly of matrix the fibrous proteins (collagen, elastin), and mucopolysaccharides, and a few scattered mesothelial cells, capillaries, venules, and ducts. Anatomists have defined several layers (Fig. 3.4) for each of the pleura. Layers 3 and 5 in Fig. 3.4 contain an abundance of fibrous protein, especially elastin. Both the interstitial (Layer 4) and mesothelial (1 and 2) layers contain capillaries of the vascular system and lymphatic channels. The matrix (ground substance) gives the pleura structural integrity and is responsible for its mechanical properties such as elasticity and distensibility. 

FIGURE 2.2 A diagram of human skin. Epidermal thickness depends upon body site being thickest on the palms and soles (-1500 pm) and thinnest around the eyes (-10 pm). The stratum corneum is the only layer composed of anucleated, terminally differentiated kerati-nocyte cells called corneocytes. All other epidermal layers contain nucleated keratinocytes. The dermis is composed primarily of the structural proteins collagen and elastin. 

Gelatin is derived from the fibrous protein collagen, which is the principal constituent of animal skin, bone, and connective tissue. Fish skin waste could be used as a potential source to isolate collagen and gelatin. Zhu et al. (2010) evaluated the effect of collagen peptides on markers of metabolic nuclear receptors. 

In contrast to milk, where samples are primarily derived from cows, meat analysis has to be performed in samples of a widely different animal origin including cattle, lamb, swine, poultry, and fish. Muscle is a complex matrix with a pH of 5.7, composed of muscle fibers, various types of connective tissue, adipose tissue, cartilage, and bones. Sarcoplasmic proteins such as myoglobin, and glycolytic enzymes are soluble in water while the myofibrillar proteins such as myosin and actin are soluble in concentrated salt solutions (14). The connective tissue proteins, collagen and elastin, are insoluble in both solvents. 

As a protein, collagen is unusual in both chemistry and structure. Nearly one-third of its residues are glycine, and an additional 20-25% are imino acids (proline and hydroxyproline). In terms of sequence, glycine occurs regularly in essentially every third position, following as a steric requirement of the secondary-tertiary structure. 

So let us have a closer look at human bone material. You might say that bone is mineralised tissue with a complex compostion. Another description of bone is a fibre-like matrix (mother matrix) in which inorganic salts are imbedded . The fibre-like matrix consists for 90-95% of the protein collagen and for about 5% of other proteins. 

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