Characterizing Length Scales that Determine the Mechanical Behavior of gels from Crosslinked Casein Micelles

Mechanical behavior of a protein gel plays a large role in sensory properties. Despite the large amount of research on caseins, the origin of the mechanical behavior is not well understood yet. To determine the length scales that are relevant for the mechanical behavior of casein gels, casein micelles were crosslinked with increasing amount of...

Microbial transglutaminases generate T cell stimulatory epitopes involved in celiac disease

Celiac disease (CD) is a permanent intolerance to gluten. In CD patients, gluten peptides cause an inflammation in the small intestine leading to tissue damage. Tissue transglutaminase (tTG) is an enzyme involved in the repair of damaged tissue by crosslinking of extracellular matrix proteins. Under certain conditions, tTG can deamidate...

Transglutaminase-Mediated Modification of Glutamine and Lysine Residues in Native Bovine β-Lactoglobulin

Bovine β-lactoglobulin (BLG) is a major component in whey and its physical properties are important for the texture of many dairy-based foods. Modification of proteins with transglutaminase from Streptoverticillium mobaraense (MTGase) can be used to alter their physical properties. MTGase-mediated modification of native BLG was until now,...

Modification of Glutamine and Lysine Residues in Holo and Apo α-Lactalbumin with Microbial Transglutaminase

The molecular structures determine the physical properties of milk proteins and are important for the texture of many dairy-based foods. Bovine α-lactalbumin (α-LA) is a globular 123 amino acid Ca2+ binding milk protein. Modification with microbial Ca2+ independent transglutaminase (MTGase) was used to modify lysines and glutamines in holo and...

Is Candida albicans a trigger in the onset of coeliac disease?

Coeliac disease is a T-cell-mediated autoimmune disease of the small intestine that is induced by ingestion of gluten proteins from wheat, barley, or rye. We postulate that Candida albicans is a trigger in the onset of coeliac disease. The virulence factor of C albicans - hyphal wall protein 1 (HWP1) - contains aminoacid sequences that are...

Transglutaminase inhibitor from milk

Cross-linking experiments of skimmed bovine milk with bacterial transglutaminase isolated from Streptoverticillium mobaraense showed only some degree of formation of high-molecular-weight casein polymers. Studies on the nature of this phenomenon revealed that bovine milk contains an inhibitor of transglutaminase activity. Removal of the casein...

Quantitation and localisation of (in vitro) transglutaminase-catalysed glutamine hydroxylation using mass spectrometry

A mass spectrometric approach was chosen to quantify and localise in vitro enzymatically modified glutamine (Gln) residues in a glutamine-rich protein. This protein (named dB1), a cloned domain of the high molecular weight wheat glutenin subunit Dx5, was modified by microbial transglutaminase (TGase) using hydroxylamine as the amine donor. Using...

Transglutaminase catalyzed reactions: Impact on food applications

Transglutaminases can perform various reactions that are based on cross-linking, acyl-transfer and deamidation. These enzymes are found in many different organisms where they have very specific roles. The basic reaction mechanism of these transglutaminases is similar. The reactions catalyzed by transglutaminases have proven to be useful in...

Aberrant fibrin formation and cross-linking of fibrinogen Nieuwegein, a variant with a shortened Aα-chain, alters endothelial capillary tube formation

A congenital dysfibrinogenemia, fibrinogenNieuwegein, was discovered in a young man without any thromboembolic complications or bleeding. A homozygous insertion of a single nucleotide (C) in codon Aα 453 (Pro) introduced a stop codon at position 454, which resulted in the deletion of the Carboxyl-terminal segment Aα 454-610. The ensuing unpaired...

Purification and substrate specificity of transglutaminases from blood and Streptoverticillium mobaraense

A procedure for a fast and simple purification of bovine plasma transglutaminase was developed, which resulted in a homogeneous enzyme preparation. Two different procedures were developed for the purification of pig erythrocyte transglutaminase, both of which resulted in partial purification. Both enzymes were used in cross-linking reactions of...

Microbial transglutaminase production by Streptoverticillium mobaraense: Analysis of amino acid metabolism using mass balances

Metabolic flows, especially those of amino acids, were determined and analyzed at different stages of a batch fermentation for microbial transglutaminase production by Streptoverticillium mobaraense. The method is mainly based on mass balances and measurements of amino acids and other metabolites. The measurements included the consumption rate...