Transglutaminase and

An old hypothesis is based on the observations of Dahlen et al. (D3), who demonstrated that above a certain concentration in plasma, Lp(a) could bind to glycosaminoglycans in the arterial wall (B12). Colocalization of Lp(a) and fibrin on the arterial wall can lead to oxidative changes in the lipid moiety of Lp(a) and induce the formation of oxidatively modified cholesterol esters, which in turn can influence the interaction of Lp(a) and its receptors on macrophages. This process is promoted by the presence of calcium ions. Cushing (C14), Loscalzo (L22), and Rath (R3) reported a colocalization of undegraded Lp(a) and apo-Bl00 in the extracellular space of the arterial wall. In contrast to LDL, Lp(a) is a substrate for tissue transglutaminase and Factor XUIa and can be altered to products that readily interact with cell surface structures (B21). 

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)... 

The production of transglutaminase by microorganisms makes it possible to apply this enzyme in a variety of food processes. An overview of the application possibilities for microbial transglutaminase in food processing is given in Table 3.5. A few of these examples will be described in some detail below, in order to show the simphcity of the treatment with microbial transglutaminase and the positive effects that can be obtained. 

Motoki, M., Seguro, K. 1998. Transglutaminase and its use for food processing. Trends Food Sci Technol 9 204-210. 

Rosell, C.M., Wang, J., Aja, S., Bean, S., Lookhart, G. 2003. Wheat flour proteins as affected by transglutaminase and glucose oxidase. Cereal Chem 80 52-55. 

Skovbjerg H, Koch C, Anthonsen D, Sjostrom H. Deamidation and cross-linking of gliadin peptides by transglutaminases and the relation to celiac disease. Biochim Biophys Acta 2004 1690 220-230. 

Michaelsson G, Ahs S, Hammarstrom I, Lundin IP, Hagforsen E. Gluten-free diet in psoriasis patients with antibodies to gliadin results in decreased expression of tissue transglutaminase and fewer Ki67+ cells in the dermis. Acta Derm Venereol 2003 83 425-429. 

Different textures can be obtained through enzymatic cross-linking of meat proteins by means of enzymes such as transglutaminase and thrombin. Details of the action... 

Pietrasik, Z., and Li-Chan, E.C.Y. (2002). Response surface methodology study on the effects of salt, microbial transglutaminase and heating temperature on pork batter gel properties. Food Res. Int. 35, 387-396. 

Introduction of sialyllactose into insulin using transglutaminase and sialyltransferase... 

Burgin-Wolff A, Dahlbom h Hadziselimovic F, Peters-son CJ. Antibodies against human tissue transglutaminase and endomysium in diagnosing and monitoring coehac disease. Scand J Gastroenterol 2002 37 685-91. 

Once thrombin binds to Tm, the complex cuts two unrelated plasma proteins, thrombin activatable fibrinolysis inhibitor (TA fibrinolysis inhibitor) and protein C, instead of fibrinogen, transglutaminase and factors Vm and V (Sect. 11.3.4). The thrombin-Tm activated (cleaved) TA fibrinolysis inhibitor is a carboxypeptidase that removes the C-terminal lysine residues. These residues are present in fibrin D-E region fragments (Fig. 11.10) following initial plasmin action, and their loss prevents a rapid acceleration of fibrinolysis (Sect. 11.4.2). 

Since many enzymes have capacities to catalyze reactions with even unnatural substrates and to produce unnatural compounds, hybrid use of enzymes as biocatalysts with chemical synthesis can realize processes to produce useful substances with higher flexibility than processes with growing cells. Discovery of novel microbial enzymes with required specificity by screening is a key to the establishment of such a hybrid processes. Many successful achievements in Japan are observed in this unique field of biotechnology. Application of nitrile hydratase to production of acrylonitriles has proved that biocatalysts can be applied to production of commodity chemicals beyond the presumed limitation of fine chemicals. Discovery of the enzymatic reactions to produce trehalose from starch is an example that reveals the possibility of microbial screening or what remains undiscovered in the microbial world. The importance of developing new application is also crucial in this field as shown in the case of transglutaminase and alkaline cellulase. 

Trespalacios, R and Pla, R. 2007. Synergistic action of transglutaminase and high pressure on chicken meat and egg gels in absence of phosphates. Food Chemistry 104 1718-1727. 

Uresti, M.R., Velazquez, G., Vazquez, M., Ramirez, A.J., and Torres, J.A. 2006. Effects of combining microbial transglutaminase and high pressure processing treatments on the mechanical properties of heat-induced gels prepared from arrowtooth flounder (Atheresthes stomias). Food Chemistry 94 202-209. 

Gan, C.Y., Cheng, L.H., Easa, A.M., 2008. Evaluation of microbial transglutaminase and ribose cross-linked soy protein isolate-based microcapsules containing fish oil. Innov. Food Set Emerg. Technol. 9, 563-569. 

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