Assays and substrates

Transglutaminases are defined as R-glutaminyl-peptide: amine γ-glutamyltransferase (EC They use a modified double-displacement mechanism to carry out an acyl transfer reaction between the γ-carboxamide group of a peptide-bound glutamine residue and the ε-amino group of a peptide-bound lysine. The active site consists of a catalytic triad (Cys, His and Asp).
The active site cysteine reacts with the γ-carbox-amide of the glutamine, forming a γ-glutamyl thioester releasing ammonia. This activated species subsequently reacts with nucleophilic primary amines, yielding either an isopeptide bond (pathway 1) or a (γ-glutamyl)amine bond (pathway 2). When an amine is not available, the acyl-enzyme intermediate reacts with water to yield glutamic acid (pathway 3).

Reaction pathway of transglutaminase
Transglutaminase reaction pathway

The incorporation of dansylcadaverine into casein (compare to pathway 2) leads to an increase in fluorescence intensity. The principle is used in kit T036.

During the transpeptidation reaction ammonia (NH3) is released. The amount of ammonia can be monitored using glutamate dehydrogenase and NADPH as co-factor. Dependent on the transglutaminase either casein or synthetic peptides serve as acyl donor substrates. The reaction can be monitored online using a UV photometer at 340 nm. An activity assays using this principle is available for MTG (M001).

The kit M003 is most sensitive allowing detection of TG2 in the picogram range using the incorporation of biotinylated peptides to microtiter plates displaying primary amines on the surface. T055 is less sensitve but more specific for TG2. After enzymatic incorporation of the biotinylated peptide, biotin is subsequently detected using streptavidin / peroxidase conjugates.

TG2 - Enzyme Immuno Assay (EIA):
The kit E018 is dedicated to determine the overall quantity of TG2. The principle behind is a sandwich EIA based on two monoclonal antibodies against tissue transglutaminase (TG2). The kit provides coated plates and all reagents necessary including a tissue transglutaminase calibrator.

The chromogenic assay kit Z009 uses Z-Gln-Gly as the amine acceptor substrate and hydroxylamine as amine donor. In the presence of transglutaminase, hydoxylamine is incorporated forming glutamyl-hxdroxamate which develops a colored complex with iron (III) detectable at 525 nm (red).

The reverse reaction of TGs is measured in the isopeptidase assays F001 and F002.


  • Zedira offers a huge portfolio of reliable specialist transglutaminase related products meant to catalyze research and development, both in academia and industry.


  • imageReversibly acting transglutaminase 2 inhibitors: drug candidates for the treatment of fibrosis
  • Zedira supports Gordon Research Conference
  • imagePress release: Zedira announces ISO 9001:2015 certification
  • imageZedira communication: Joint poster presentation on “Feasibility of a new automated FXIII activity assay”
  • imageArtikel in DZG Aktuell 01/2019 über die klinische Wirksamkeitsstudie unseres potentiellen Zöliakie Medikaments (deutsch)
  • imagePreview: Catalogue Editorial 2019
  • Press release: Dr. Falk Pharma and Zedira announce start of the phase 2a proof of concept study of ZED1227 for the treatment of celiac disease
  • Artikel in DLG-Lebensmittel – 06/2017 zur Bestimmung von Transglutaminase in Lebensmitteln (deutsch)
  • Zedira publication: Microbial Transglutaminase Used in Bread Preparation at Standard Bakery Concentrations Does Not Increase Immunodetectable Amounts of Deamidated Gliadin
  • Pressemitteilung: Dr. Falk Pharma und Zedira geben den Abschluss der Phase 1b-Studie für ZED1227 zur Zöliakie-Therapie bekannt und planen Start der Wirksamkeitsstudie
  • Press release: Dr. Falk Pharma and Zedira announce completion of phase 1b clinical trial of ZED1227 for the treatment of celiac disease and move on to proof of concept study
  • Press Release: Dr. Falk Pharma GmbH and Zedira enter a phase 1b clinical trial for a celiac disease drug
  • Zedira publication: Microbial transglutaminase has a lower deamidation preference than human tissue transglutaminase on a celiac disease relevant wheat gliadin T-cell epitope
  • Press release: Additional subsidy funding for clinical development of a celiac disease drug
  • Pressemitteilung: Zusätzliche Fördermittel für die klinische Entwicklung eines Zöliakie-Medikamentes
  • Press Release: Cooperation between Zedira and Cardiff University - Transglutaminase 6 is the focus of new research into ataxia
  • Press Release: Dr. Falk Pharma and Zedira enter phase I clinical trials for a celiac disease drug
  • Press release: Zedira receives further funding to develop Factor XIIIa-blockers for safe anticoagulation



  • 19th International Celiac Disease Symposium

    14.10.2021 - 17.10.2021
    Sorrento, Italy

  • Gordon Research Conference: Transglutaminases in Human Disease Processes

    12.06.2022 - 17.06.2022
    Mount Snow, USA