Food-related transglutaminase obtained from fish/shellfish

Transglutaminase in Foods and Biotechnology

Stabilization and reusability of enzyme transglutaminase (TGM) are important goals for the enzymatic process since immobilizing TGM plays an important role in different technologies and industries. TGM can be used in many applications. In the food industry, it plays a role as a protein-modifying enzyme, while, in biotechnology and pharmaceutical applications, it is used in mediated bioconjugation due to its extraordinary crosslinking ability. TGMs (EC 2.3.2.13) are enzymes that catalyze the formation of a covalent bond between a free amino group of protein-bound or peptide-bound lysine, which acts as an acyl acceptor, and the γ-carboxamide group of protein-bound or peptide-bound glutamine, which acts as an acyl donor. This results in the modification of proteins through either intramolecular or intermolecular crosslinking, which improves the use of the respective proteins significantly.

Roles and potential clinical implications of tissue transglutaminase in cardiovascular diseases

Cardiovascular disease (CVD)-related mortality and morbidity are among the most critical disease burdens worldwide. CVDs encompass many diseases and involve complex pathogenesis and pathological changes. While research on these diseases has advanced significantly, treatments and their efficacy remain rather limited. New therapeutic strategies and targets must, therefore, be explored. Tissue transglutaminase (TG2) is pivotal to the pathological development of CVDs, including participating in the cross-linking of extracellular proteins, activation of fibroblasts, hypertrophy and apoptosis of cardiomyocytes, proliferation and migration of smooth muscle cells (SMCs), and inflammatory reactions. Regulating TG2 activity and expression could ensure remarkable improvements in disorders like heart failure (HF), pulmonary hypertension (PH), hypertension, and coronary atherosclerosis. In this review, we summarize recent advances in TG2: we discuss its role and mechanisms in the progression of various CVDs and its potential as a diagnostic and therapeutic target.

Contribution of Special Structural Features to High Thermal Stability of a Cold-Active Transglutaminase

A cold-active transglutaminase (TGase, EC 2.3.2.13) that catalyzes the reaction of protein glutamine + protein lysine ↔ protein with γ-glutamyl-ε-lysine cross-link + NH₃ at low temperatures was reported previously. This study verified the thermal stability of the TGase from 0-80 °C. Fluorescence and CD spectra studies confirmed tertiary structural damage at 40 °C, α-helix reduction at 60 °C, and refolding during cooling to 20 °C. The TGase sequence was obtained by transcriptomics and used to build its structure. Its catalytic triad was Cys333-His403-Asp426 and its catalytic process was inferred from the model. Molecular dynamics simulation illustrated that its cold activity resulted from its flexible active site, while high thermostability was conferred by an overall rigid structure, a large amount of stable Val and Lys, and strong electrostatic interactions at the N- and C- terminals. This study fills gaps in the correlation of conformational changes with stability and activity of TGase.

Assessing the Biological Safety of Atmospheric Cold Plasma Treated Wheat Using Cell and Insect Models

Atmospheric cold plasma (ACP) is under investigation for an extensive range of biocontrol applications in food biosystems. However, the development of a novel intervention technology requires a thorough evaluation of the potential for negative effects and the implications for the human and animal food chains’ safety. The evaluations were performed using a contained, high-voltage, dielectric barrier discharge plasma system. The cytotoxicity of two types of food models—a liquid model (wheat model medium (WMM)) vs. a solid model (wheat grain extract (WGE)) was compared in vitro using the mammalian cell line CHO-K1. The residual toxicity of ACP treatment of grains for food purposes was assessed using the invertebrate model Tribolium castaneum, by feeding the beetles with flour produced from ACP-treated wheat grains. The cytotoxic effects and changes in the chemistry of the ACP-treated samples were more pronounced in samples treated in a liquid form as opposed to actual wheat grains. The feeding trial using T. castaneum demonstrated no negative impacts on the survivability or weight profiles of insects. Investigations into the interactions of plasma-generated species with secondary metabolites in the food matrices are necessary to ensure the safety of plasma for food applications.