Fibrous solubility

Albumen has the largest number of acid and basic groups. It is the most soluble of the proteins present in a hide. The albumen is not a fibrous material, however, and therefore has no value in the leather. Keratin is the protein of the hair and the outermost surface of the hide. Unless the hair is desired for the final product it is removed by chemical and/or physical means. The elastin has Htde acid- or base-binding capacity and is the least soluble of the proteins present. The lack of reactivity of the elastin is a detriment for most leather manufacture. The presence of elastin in the leather greatly limits the softness of the leather. 

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. 

Heavy meromyosin (HMM molecular mass about 340 kDa) is a soluble protein that has both a fibrous portion and a globular portion (Figure 49-4). It exhibits ATPase activity and binds to F-actin. Digestion of HMM with papain generates two subfragments, S-1 and S-2. The S-2 fragment is fibrous in character, has no ATPase activity, and does not bind to F-actin. 

Denaturation and aggregation of whey proteins are affected by the pH of extrusion. When extruding WPI, alkaline conditions increase denaturation and solubility, decrease pasting properties, and produce more pronounced microstructural changes (Onwulata et ah, 2006). Denaturation in the extruder causes whey proteins to form small primary aggregates that combine to form large clusters. The clusters are then aligned by shear to form fibrous structures. 

Preparation of Soluble Sample for Decarboxylation. The photolyzed fabric swatch was placed in 20 ml of distilled DMAc at 100°C for 5 minutes. The DMAc solution was filtered to remove any insoluble fibrous material from the decarboxylation flask (a round 30 ml two-neck Pyrex flask with a protruded bottom well) and dried in vacuo with the temperature kept below 50°C leaving a residual film on one side of the flask. 

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

Dyes, often also called coloring matters or colorants, are intensely colored, soluble organic substances used to impart color to fibrous materials (see Textbox 66). Not all colored and soluble organic substances, however, are dyes only those whose molecules have a considerable structural complexity are useful for imparting color to other materials. Moreover, a substance is considered a dye only if the color it imparts is fairly permanent, that is, resistant to fading and disappearance. 

An enantiotropically related pair of polymorphs was obtained for p-aminoben-zoic acid, with the system being characterized by a transition temperature of 25 °C [31]. The a-form was obtained as fibrous needles, while the /M orm was obtained in the form of prisms. The solubilities of the two forms are almost the same, indicating the existence of comparable values for AG, which in turn explained the slow transformation of the a-form into the [>-form. Nucleation of the a-form was found to be favored, which is reasonable considering that the structural motif of the a-form consists of carboxylic acid dimmers that would be expected to be stable association species in solution. 

---