Soluble fibrous proteins

The major types of cytoskeletal filaments are 7-nm-thick microfilaments. 25-nm-thick microtubules, and 10-nm-thick intermediate filaments (IPs). These are respectively composed of actin, tubulin, and a variety of interrelated sparsely soluble fibrous proteins termed intermediate filament proteins. In addition, thick myosin filaments are present in large numbers in skeletal and heart muscle cells and in small numbers in many other types of eukaryotic cells. 

Intracellular space Fibrous protein ( 65-70%), nonfibrous (soluble) protein ( 5-10%) 75... 

The alpha helix represents the second major structural element of soluble proteins108 128 and is also found in many fibrous proteins, including those of muscle... 

Fibrinogen is a fibrous protein that was first classified with keratin, myosin, and epidermin based on its 5.1 A repeat in wide-angle X-ray diffraction patterns (Bailey et al., 1943), which was later discovered to be associated with the Q-helical coiled-coil structure. It is a glycoprotein normally present in human blood plasma at a concentration of about 2.5 g/L and is essential for hemostasis, wound healing, inflammation, angiogenesis, and other biological functions. It is a soluble macromolecule, but forms a clot or insoluble gel on conversion to fibrin by the action of the... 

Meat is the muscular tissue of the common domestic animals, considered and used as food for human consumption. Meat is at least a three-phase system consisting of (1) a hydrophilic, but water-insoluble, fibrous protein network, (2) a hydrophobic fat deposit held together by membranes, and (3) an aqueous solution containing many soluble, low molecular weight compounds. 

Globular proteins have many of the secondary structures of fibrous proteins, but they do not contain extended (long) p-sheets and have numerous a-helical substructures. They frequently contain amino acids with polar side chains that contribute to their water solubility. In globular proteins, the primary sequence of amino acids tend to fold into spherical shapes. 

Proteins are often referred to as globular and fibrous proteins according to their conformation. Globular proteins are usually soluble in water, whilst fibrous proteins are usually insoluble. The complex nature of their structures has resulted in the use of a sub-classification, sometimes referred to as the order of protein structures. This classification divides the structure into into primary, secondary, tertiary and quaternary orders of structures. 

A class of proteins that are stringy, tough, threadlike, and usually insoluble in water, (p. 1190) A class of proteins that are relatively spherical in shape. Globular proteins generally have lower molecular weights and are more soluble in water than fibrous proteins, (p. 1190)... 

Keratin in the cortex comprises 85% or more of the mass of the hair shaft. Cortical keratin is composed of two types of structural proteins, matrix proteins and fibrous proteins. 2-1 Matrix proteins have a high sulfur content and contain polypeptides with a molecular weight of approximately 10 to 28 kDa. Fibrous proteins are embedded in matrix proteins and are characterized by a low sulfur content. They have a molecular weight of approximately 40 to 58 kDa. Also, matrix proteins have a nonhelical structure and are readily soluble at pH 4.5 in 0.5 M KCl, whereas fibrous proteins exhibit a helical structure and are insoluble in this same solution. 

The soluble proteins derived from elastin retain the yellow color of the fibrous protein, and also its strong blue-white fluorescence, and the pigment cannot be removed by further mild hydrolysis and exhaustive dialysis or repeated precipitation with alcohol. It thus appears that a fluores-... 

The fibrous protein collagen, the major constituent of skin and bone, is derived from procollagen, a soluble precursor. 

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