Proteins animal glues

Animal glue is a complex colloidal mixture of proteins. The related gelatins are also complex heterogeneous mixtures of proteins. They are strongly hydrophilic and rich in the amino acids glycine, proline, lysine, hydroxyproline and hydroxylysine. Casein is a phosphoprotein obtained from the milk of mammals. 

Proteins Egg, milk and casein, animal glue, silk, wool, vegetable proteins (e.g. garlic, beans), human and animal tissues (e.g. mummies) Paint binders, adhesives, textiles, commodities, parchment... 

U. Schneider, E. Kenndler, Identification of Plant and Animal Glues in Museum Objects by GC MS, After Catalytic Hydrolysis of the Proteins by the Use of a Cation Exchanger, with Simultaneous Separation from the Carbohydrates, Fresenius Journal of Analytical Chemistry, 371,81 87 (2001). 

Polar groups contribute greatly to adhesion of proteins to carbohydrates and to their cohesion. In denatured or unfolded proteins, such as animal glues, the peptide amide groups play an important role in adhesion but in the undenatured collagen, most peptide groups are associated in helical conformations. 

Animal glue Glue made of protein-containing products, particularly of animal waste (bones), on aqueous basis. 

In addition to its importance in the production of animal glue, collagen is the basis for gelatin, which forms when collagen fibers are denatured as a result of heating and then get tangled up with each other. Collagen is also used for various biomedical applications, see also Denaturation Peptide Bond Proteins. 

This class of adhesives contains some of the most traditional materials, for example animal glues and gums derived from natural sources, which are long-chain molecules, are soluble in water, and are either proteins or polysaccharides. Modern technology has brought other water-soluble materials into use for example, poly( vinyl alcohol) adhesives, and a host of resins based on phenol, mea, and formaldehyde (see Formaldehyde Resins in Chapter 4). 

In contrast to their widespread use in furniture and paper products, animal glues have not proved useful as struetural adhesives for wood. When used as the principal protein constituent, their water sensitivity is excessive compared with other available proteins. When eombined with soybean, blood, or casein, animal gelatin glues are completely hydrolyzed and destroyed by the strong alkalies required to disperse these proteins. In addition, they soften when severely heated, which, by law, prohibits their use in structural wood products [5]. 

Animal glues are derived by the hydrolysis of the protein constituent collagen of animal hides and bones. Collagen in its natural state is water insoluble and must be conditioned to solubilize the protein. Collagen molecules are triple helices of amino acid sequences and contain both nonpolar and charged acidic and basic side chains. The conversion of... 

Selected animal glues, also known as technical gelatins, are used in the production of protein hydrolysates for use as a source of protein in such products as cosmetics, shampoos, and skin care lotions and creams. Generally, the glue protein is hydrolyzed to a molecular weight below 2000 by use of enzyme, acid, or alkaline treatment. 

Uses Fertilizer animal feed supplement stabilizer for resins, plastics, explosives softener for cellulose in paper industry deodorizer penetrant cure accelerator and activator airport runway deicing agent dispersant (animal glue, proteins) plasticizer for starch adhesives food additive, yeast nutrient, fermentation aid flour treatment agent diuretic, antiseptic in pharmaceuticals antistat, humectant in cosmetics keratin softenerfor dry skin prods. in ammoniated dentifrices in side seam cements for food-contact containers... 

These materials are building blocks of animal tissues. To a lesser extent they are also found in vegetable sources. Because the major constituents of animal bodies, including skins, hairs, and blood, are proteins, they are of much greater interest to the biochemists. Nevertheless, some proteins are important commercial materials. These include animal glues, silk, and wool. It is beyond the scope of this book, however, to render a thorough discussion of the proteins. For that reason, only some basic principles are presented here. 

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