Clarke et al. introduced the term transglutamine in 1957 to describe the transamidating activity observed in guinea-pig liver. Transamidating is the transferal of an amide group from one compound to another. Amides (RC(O)NR2) and esters (RC(O)OR’) are classes of acyl compounds. (Griffin, M. et al.; 2002)
“Later studies undertaken by Pisano et al., on the stabilization of fibrin monomers during blood clotting, demonstrated that transamidation (transferal of an amide group from one compound to another) is brought about by enzymes which cross-link proteins through an acyl-transfer reaction between the γ-carboxamide group of peptide-bound glutamine and the ε-amino group of peptide-bound lysine, resulting in a ε-(γ-glutamyl)lysine isopeptide bond (Griffin, M. et al.; 2002)
It was known that a similar enzyme plays a role in moulding fish protein pasts into Kamaboko, a popular Japanese dish. A food research group at Ajinomoto Co. “confirmed rapid gelation of several food protein solutions by the enzyme obtained from guinea-pigs liver, which led to the following development of the microbial transglutaminase jointly with Amano Pharmaceutical Company.” (Fiechter, A.; 2000: 57)
During the 1980’s Yokoyama, Nio and Kikuchi from Ajinomoto were involved “in investigating the feasibility of modifying food protein in industrial applications using the guinea pig liver enzyme and they used whey proteins and actomyosin from beef, pork, chicken or fish as substrates that could be gelled. Subsequently, improvements in the solubility, water-holding capacity and thermal stability of food proteins were demonstrated” (Yokoyama, K., et al.; 2004) which today forms the basis of its application in meat processing.
The use of guinea pig livers was however unacceptable for use in food manufacturing and it hindered its commercialization. The critical issue was the mass production of transglutaminase. (Yokoyama, K., et al.; 2004) Yokoyama, Nio and Kikuchi from Ajinomoto, in collaboration with Amano Enzyme Co. (Nagoya, Japan) set out to find a constant supply of transglutaminase. In the process, they screened around 5,000 microorganisms for transglutaminase “and identified some microorganisms that produce TGase-like enzymes using the hydroxamate assay (Ando et al. 1989). These microorganisms excreted the enzyme, and one of them produced a high activity. The enzyme in the latter strain was shown to form G-L bonds in proteins, the critical property of a Transglutaminase (Nonaka et al. 1989); it was named microbial transglutaminase (which I abbreviate as MTG), and the source was classified as a variant of S. mobaraensis (Washizu et al. 1994).” (Yokoyama, K., et al.; 2004)
The enzyme is capable of gelling concentrated solutions of proteins such as soybean protein, milk proteins, and gelatin and myosin of various origins to produce gels with novel physical properties. The enzyme also causes crosslinking of two or more different proteins to produce new protein conjugates with novel functions. (Fiechter, A.; 2000: 57) The same microbial transglutaminase was later isolated in Physarum polycephalum and in Bacillus subtilis spores. (Kieliszek, M and Misiewicz, A.; 2013)
In mammals, transglutaminase requires Calcium. “Shimba et al. (2002); Washizu et al. (1994) and Ando et al. (1989) found that transglutaminase isolated from Streptoverticillium mobaraense did not require calcium ions” (Kieliszek, M and Misiewicz, A.; 2013)
The properties of microbial transglutaminase, its ability to cross-link most food proteins, find tremendous application in binding meat together in the process of restructuring. It is also known to dramatically increases the ability of proteins for emulsification with great impact on the use of soy proteins for example in sausage production. (Fiechter, A.; 2000: 57) It improves muscle texture and therefore product quality and assists in the reshaping of large muscles.
An EarthwormExpress Project. Visit our website and stay up to date with the most recent updates.
Email Eben at email@example.com