Transglutaminase 2 (TG2) is an inducible transamidating acyltransferase that catalyzes Ca2+-dependent protein modifications. TG2 enzyme disruption has been implicated in several different disease processes and disorders such as Huntington and Parkinson’s diseases, cancers such as breast, ovarian and pancreatic cancers. Coeliac disease (CD) is the one disease state that TG2 activity plays a crucial role. To date, a gluten-free diet is the only accepted form of therapy for CD. Because of the important role of TG2 enzyme in the initiation of CD, therefore, this study was aimed at the identification of TG2 inhibitors from natural sources, as a potential intervention in CD therapy. Competitive amine inhibitors are the most widely used TG2 inhibitors because they are commercially available, chemically stable and relatively non-toxic in living systems. The natural products chosen for this study were dietary flavonoids. Flavonoids were extracted from different food samples. The flavonoids food extracts were subjected to the TG2 activity assays to examine their effect on the enzyme activity. The assays were carried out under optimal conditions of pH, Ca2+ and with N, N-dimethylcasein (acyl-donor) or casein (acyl-acceptor) as acyl-donor substrates and biotin cadaverine (acyl-acceptor) or TVQQEL as (acyl-donor) substrates. TG activity was measured by two different microplate assays, Biotin-labeled cadaverine incorporation assay and Biotin-labeled peptide cross-linking assay. In the TG2 amine incorporation activity, all of food extracts display a significant inhibition effect towards the human recombinant transglutaminase2 (hrTG2) and guinea pig transglutaminase 2 (gplTG2) (20 - 50% of inhibition). While in the TG2 cross-linking activity, the majority of food extracts displayed an inhibition effect on the gplTG2 cross-linking activity (50 - 70% of inhibition) but only the strawberry and kale extracts showed an effect on hrTG2 activity (40 - 50% of inhibition). The inhibition of TG2 activity can be considered as a potential therapeutic target in the treatment of CD.
1. Lorand L, Graham RM (2003) Transglutaminases: cross-linking enzymes with pleiotropic functions. Nature Reviews, Molecular Cell Biology. 4 (2): 140-156. doi: 10.1038/nrm1014.
2. Hoffner G, Djian P (2005) Transglutaminase and diseases of the central nervous system. Frontiers in Biosciences. 10: 3078-3092. doi: 10.2741/1764.
3. Mangala LS, Mehta K (2005) Tissue transglutaminase (TG2) in cancer biology. Progress in Experimental Tumor Research. 38: 125-138. doi: 10.1159/000084237.
4. Bernassola F, Federici M, Corazzari M, Terrinoni A, Hribal ML, De Laurenzi V, Ranalli M, Massa O, Sesti G, McLean WH, Citro G, Barbetti F, Melino G (2002) Role of transglutaminase 2 in glucose tolerance: knockout mice studies and a putative mutation in a MODY patient. FASEB Journal. 16 (11): 1371-1378. doi. org/10. 1096/fj.01-0689com.
5. Parkkola A, Härkönen T, Ryhänen SJ, Uibo R, Ilonen J, Knip M, Finnish Pediatric Diabetes Register (2018) Transglutaminase antibodies and celiac disease in children with type 1 diabetes and in their family members. Pediatric Diabetes. 19 (2): 305-313. doi: 10.1111/pedi.12563.
6. Molberg Ø, McAdam SN, Sollid LM (2000) Role of tissue transglutaminase in celiac disease. Journal of Pediatric Gastroenterology and Nutrition. 30 (3): 232-240. doi: 10.1097/00005176-200003000-00005.
7. Plugis NM, Khosla C (2015) Therapeutic approaches for celiac disease. Best Practice and Research Clinical Gastroenterology. 29 (3): 503-521. doi: 10.1016/j.bpg.2015.04.005.
8. Hall NJ, Rubin GP, Charnock A (2013) Intentional and inadvertent non-adherence in adult coeliac disease. A cross-sectional survey. Appetite. 68: 56-62. doi: 10.1016/j.appet.2013.04.016.
9. Ford S, Howard R, Oyebode J (2012) Psychosocial aspects of coeliac disease: a cross‐sectional survey of a UK population. British Journal of Health Psychology. 17 (4): 743-757. doi. org/10.1111/j.2044-8287.2012.02069.x.
10. Cosnes J, Cellier C, Viola S, Colombel J, Michaud L, Sarles J, Hugot J, Ginies J, Dabadie A, Mouterde O, Allez M, Nion-Larmurier I (2008) Incidence of autoimmune diseases in celiac disease: protective effect of the gluten-free diet. Clinical Gastroenterology and Hepatology. 6 (7): 753-758. doi. org/10.1016/j.cgh.2007.12.022.
11. Häuser W, Gold J, Stein J, Caspary WF, Stallmach A (2006) Health-related quality of life in adult coeliac disease in Germany: results of a national survey. European Journal of Gastroenterology and Hepatology. 18 (7): 747-754. doi: 10.1097/01.meg.0000221855.19201.e8.
12. D'Argenio G, Amoruso DC, Mazzone G, Vitaglione P, Romano A, Ribecco MT, D'Armiento MR, Mezza E, Morisco F, Fogliano V, Caporaso N (2010) Garlic extract prevents CCl(4)-induced liver fibrosis in rats: The role of tissue transglutaminase. Digestive and Liver Disease. 42 (8): 571-577. doi: 10.1016/j.dld.2009.11.002.
13. De Jong G, Wijngaards G, Koppelman S (2003) Transglutaminase inhibitor from milk. Journal of Food Science. 68 (3): 820-825. doi: 10.1111/j.1365-2621.2003.tb08249.x.
14. Aldubayan M (2014) The isolation and characterisation of Transglutaminase 2 inhibitors from natural sources. Biology Chemistry. Corpus ID: 86953650.
15. Rzepecka-Stojko A, Stojko J, Kurek-Górecka A, Górecki M, Kabała-Dzik A, Kubina R, Moździerz A, Buszman E (2015) Polyphenols from bee pollen: structure, absorption, metabolism and biological activity. Molecules. 21 (2): 21732-21749. doi. org/10.3390/molecules201219800.
16. Huang L, Xu AM, Liu W (2016) Transglutaminase 2 in cancer. American Journal of Cancer Research. 5 (9): 2756-2776. PMID: 26609482.
17. Mohana M, Ganesan B, Agilan R, Karthikeyan G, Srithar R, Beaulah Mary D, Ananthakrishnan D, Velmurugan N, Rajendra P, Suresh V, Ambudkard Mohana MS (2016) Screening dietary flavonoids for the reversal of P-glycoprotein-mediated multidrug resistance in cancer. Molecular BioSystems. 12 (8): 2458-2470. doi: 10.1039/ c6mb00187d.
18. Huyut Z, Beydemir Ş, Gülçin İ (2017) Antioxidant and antiradical properties of selected flavonoids and phenolic compounds. Biochemistry Research International. 2017:7616791.1. doi.org/10.1155/2017/7616791.
19. Xue G, Gong L, Yuan C, X, M, Wang X, Jiang L, Huan, M (2017) A structural mechanism of flavonoids in inhibiting serine proteases. Food & Function. 8 (7): 2437-2443. doi: 10.1039/c6fo01825d.
20. Folk J, Cole P (1966) Transglutaminase: mechanistic features of the active site as determined by kinetic and inhibitor studies. Biochimica Et Biophysica Acta (BBA)-Enzymology and Biological Oxidation. 122 (2): 244-264. doi.org/10.1016/0926-6593(66)90066-X.
21. Sollid LM, Jabri B (2011) Celiac disease and transglutaminase 2: a model for posttranslational modification of antigens and HLA association in the pathogenesis of autoimmune disorders. Current Opinion in Immunology. 23 (6): 732-738. PMC4633903.
22. Slaughter TF, Achyuthan KE, Lai T, Greenberg CS (1992) A microtiter plate transglutaminase assay utilizing 5-(biotinamido) pentylamine as substrate. Analytical Biochemistry. 205 (1): 166-171.
23. Lilley GR, Griffin M, Bonner PL (1997) Assays for the measurement of tissue transglutaminase (type II) mediated protein crosslinking via epsilon-(gamma-glutamyl) lysine and N',N'-bis (gamma-glutamyl) polyamine linkages using biotin labelled casein. Journal of Biochemistry and Biophysics Methods. 34 (1): 31-43. doi: 10.1016/s0165-022x(96)01200-6.
24. Negretti NM, Gourley CR, Clair G, Adkins JN, Konkel ME (2017) The food-borne pathogen Campylobacter jejuni responds to the bile salt deoxycholate with countermeasures to reactive oxygen species. Scientific Reports. 7 (1): 15455. doi: 10.1038/s41598-017-15379-5.
25. Stoven S, Murray JA, Marietta EV (2013) Latest in vitro and in vivo models of celiac disease. Expert Opinion on Drug Discovery. 8 (4): 445-457. doi: 10.1517/17460441.2013.761203.
26. Peräaho M, Kaukinen K, Paasikivi K, Sievänen H, Lohiniemi S, Mäki M, Collin P (2003) Wheat‐starch‐based gluten‐free products in the treatment of newly detected coeliac disease: prospective and randomized study. Alimentary Pharmacology and Therapeutics. 17 (4): 587-594. doi.org/10.1046/j.1365-2036.2003.01425.x.
27. Bascunan KA, Vespa MC, Araya M (2017) Celiac disease: understanding the gluten-free diet. European Journal of Nutrition. 56 (2): 449-459. doi: 10.1007/s00394-016-1238-5.
28. Malik NA (2016) Solubilization and interaction studies of bile salts with surfactants and drugs: a review. Applied Biochemistry and Biotechnology. 179 (2): 179-201. doi: 10.1007/s12010-016-1987-x.
29. Pannala AS, Chan TS, O'Brien PJ, Rice-Evans CA (2001) Flavonoid B-ring chemistry and antioxidant activity: fast reaction kinetics. Biochemical and Biophysical Research Communications. 282 (5): 1161-1168. doi: 10.1006/bbrc.2001.4705.
30. Burda S, Oleszek W (2001) Antioxidant and antiradical activities of flavonoids. Journal of Agricultural and Food Chemistry. 49 (6): 2774-2779. doi: 10.1021/jf001413m.
31. Pinkas DM, Strop P, Brunger AT, Khosla C (2007) Transglutaminase 2 undergoes a large conformational change upon activation. PLoS Biology. 5 (12): e327. doi: 10.1371/journal.pbio.0050327.