On-chip dual enzyme activity assay to investigate regulation of the transamidase and kinase activities of transglutaminase 2

• Published in: Analytica chimica acta 2018-10, Vol.1027, p.92-100
• Main Authors: Jung, Se-Hui, Jeon, Hye-Yoon, Lee, Seong-Hyeon, Han, Eun-Taek, Park, Won Sun, Hong, Seok-Ho, Kim, Young-Myeong, Ha, Kwon-Soo
• Format: Article
• Language: English
• Subjects: Acetylation; Assaying; Bioassays; Biocompatibility; Biomedical materials; Calcium; Calcium ions; Cellular biology; Cofactors; Conformation; Dephosphorylation; Diamonds; Enzymatic activity; Enzyme activity; Enzymes; Kinase; Kinases; Magnesium; On-chip dual enzyme activity assay; Osteopontin; Pathogenesis; Phosphorylation; Protein arrays; Regulators; Transamidase; Transglutaminase 2
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/j.aca.2018.04.021

Transglutaminase 2 (TGase2), a multifunctional enzyme exhibiting both transamidase and kinase activity, is involved in a variety of cellular processes and diseases. However, details of the regulation of TGase2 have not been reported due to the lack of a suitable assay to examine both activities on the same platform under near-physiologic conditions. Thus, we developed an on-chip dual enzyme activity assay for TGase2 to simultaneously monitor the transamidase and kinase activities. Reaction mixtures specific for each enzyme activity were applied onto osteopontin arrays, and enzyme activity was monitored by sequential probing with Cy5-strepavidin and Pro-Q Diamond stain. This approach was used to determine the optimal concentrations of ATP, Mg2+, and Ca2+ for dual-activity assays. The optimized assay was then used to investigate regulation of TGase2 transamidase and kinase activities by various cofactors that could potentially affect its conformation. Monothiol- and disulfide-containing compounds differentially regulated TGase2 transamidase and kinase activities. Acetylation of TGase2 activated the kinase activity but had no effect on the transamidase activity. Phosphorylation and dephosphorylation of TGase2 reciprocally regulated the transamidase and kinase activities. The new approach described here is thus useful for screening potential regulators of TGase2 transamidase and kinase and investigating the pathogenesis of TGase2-associated diseases. [Display omitted] •We developed an on-chip dual enzyme activity assay for transglutaminase 2 to simultaneously monitor the transamidase and kinase activities.•We determined the optimal concentrations of cofactors.•We characterized the allosteric regulation of TGase2 transamidase and kinase activities.•This new assay is useful for screening potential allosteric regulators of TGase2 transamidase and kinase.•Investigating the pathogenesis of TGase2-associated diseases.