Proteolytic enzyme resistant product

These should not be confused with oil-tanned skins such as chamois wash-leathers or the buff leathers employed widely by seventeenth century armies to make protective jerkins. These are not impregnated with stable, water-repellent fats but treated with reactive, oxidisible oils, which undergo chemical reactions with the skin during processing to give a proteolytic enzyme-resistant product. 

The precipitation and cross-linking of an enzyme combines its isolation and immobilization into a single step. Enzymes prepared in this way are usually highly productive, stable, and resistant to denaturation (loss of enzyme function by structural alteration) due to exposure to organic solvents, heating, or breakdown to shorter peptide chains or amino acids by the action of proteolytic enzymes (proteolysis). 

Animal glue is essentially the hydrolytic product of collagen, the main protein in animal skins and bones. Collagen as its exists in its natural state is water-insoluble and resistant to mild acids and alkalies as well as proteolytic enzymes other than the collagenases. Veis and Cohen discuss the structure of collagen ... 

In some instances there is a possibility that the efficacy of these preparations may be compromised by conditions associated with the digestive tract. Most function at pH values approaching neutrality. They would thus display activity possibly in saliva and particularly in the small intestine. However, the acidic conditions of the stomach (where the pH can be below 1.5) may denature some of these enzymes. Furthermore, the ingested enzymes would also be exposed to endogenous proteolytic activities associated with the stomach and small intestine. Some of these difficulties, however, may be at least partially overcome by formulating the product as a tablet coated with an acid-resistant film to protect the enzyme as it passes through the stomach. 

Bacteria represent a promising source for the production of industrial enzymes. Bacterial cellulases are an especialfy interesting case in point. Many thermophilic bacterial species produce cellulases that are stable and active at high temperature, resistant to proteolytic attack, and stable to mechanical and chemical denaturation. However, cellulase productivities in bacteria are notoriously low compared to other microbial sources. In this paper bacterial enzyme production systems will be discussed with a focus on comparisons of the productivities of known bacterial cellulase producers. In an attempt to draw conclusions concerning the regulation of cellulase synthesis in bacterial systems, a tentative model for regulation in Acidothennus cellulofyticus has been developed. 

In vitro, the enzyme is able to catalyze crosslinking of whey proteins, soy proteins, wheat proteins, beef myosin, casein, and crude actomyosin (which is refined from mechanically deboned meat), improving functional properties such as the texture of food products [49-53], Bonds formed by transglutaminase exhibit a high resistance to proteolytic degradation [54],... 

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