Protease transglutaminase

An enzyme reaction intermediate (Enz—O—C(0)R or Enz—S—C(O)R), formed by a carboxyl group transfer (e.g., from a peptide bond or ester) to a hydroxyl or thiol group of an active-site amino acyl residue of the enzyme. Such intermediates are formed in reactions catalyzed by serine proteases transglutaminase, and formylglyci-namide ribonucleotide amidotransferase . Acyl-enzyme intermediates often can be isolated at low temperatures, low pH, or a combination of both. For acyl-seryl derivatives, deacylation at a pH value of 2 is about 10 -fold slower than at the optimal pH. A primary isotope effect can frequently be observed with a C-labeled substrate. If an amide substrate is used, it is possible that a secondary isotope effect may be observed as welF. See also Active Site Titration Serpins (Inhibitory Mechanism)... 

Fibrin is formed from fibrinogen synthesized by the liver and secreted into the circulation. The conversion of fibrinogen to fibrin is initiated by a serine protease, thrombin. Thrombin, at the same time, can activate a transglutaminase enzyme, factor XIII present in... 

Besides the proteases, which have been investigated extensively and are the only modifying enzymes currently in use commercially, there are transglutaminase, protein kinase, and peptidoglutaminase. These enzymes have only been reported for use in food protein modification on a laboratory scale. Feeney and Whitaker (1977, 1982, 1986) addressed possible... 

Babiker, E.F.E., Fujisawa, N., Matsudomi, N., Kato, A. (1996). Improvement of the functional properties of gluten by protease digestion or acid hydrolysis followed by microbial transglutaminase treatment. J. Agric. Food Chem., 44, 3746-3750. 

Apoptosis (programmed cell death) is characterized by a complex series of biochemical changes that culminate in cell death without inflammation or swelling, which are signs of necrosis. Embryonic, fetal, and postnatal development involve cell death by apoptosis, which serves to eliminate excessive cell proliferation and migration. Apoptosis is initiated by a variety of external stimuli and molecular events such as oxidative stress, mitochondrial permeability transition, mitochondrial cytochrome c release, activation of caspase proteases, activation of endonucleases, transglutaminase activation, and poly(ADP-ribose) polymerase cleavage. 

Modification of proteins by transglutaminase [14,15,16,17,18], peptidoglutaminase [19,20,21,22], and protein kinase [23,24] on a laboratory scale has been reported. Whitaker [25] discussed in great detail the impact of these potential modifications on the structure and properties of the proteins. However, the effect of proteinoses on proteins has been extensively investigated, and proteinases are the only protein-modifying enzymes currently in commercial use. However, immobilizing proteases proved to be very effective in enzymatic peptide modification [26]. From the aspect of human health and safety, the use of proteinases in protein modification should offer better... 

Hartley DM, Zhao C, Speier AC, Woodard GA, Li S, Li Z, Walz T (2008) Transglutaminase induces protofibril-like amyloid beta-protein assemblies that are protease-resistant and inhibit long-term potentiation. J Biol Chem 283 16790-16800 Hashimoto M, Rockenstein E, Crews L, MasUah E (2003) Role of protein aggregation in mitochondrial dysfunction and neurodegeneration in Alzheimer s and Parkinson s diseases. Neuromolecular Med 4 21-36... 

Protein TC] Protein, animal, hydrolyzed. See Hydrolyzed collagen Proteinase. See Protease Protein-glutamine-y-glutamyltransferase. See Transglutaminase... 

Kikuchi Y, Date M, Yokoyama K, Umezawa Y, Matsui H. (2003). Secretion of active-form Streptoverticillium mobaraense transglutaminase by Corynebacterium glutamicum processing of the pro-transglutaminase by a cosecreted subtilisin-like protease from Strepto-myces albogriseolus. Appl Environ Microbiol, 69, 358-366. 

---