NTU Undergraduates' research April 2014 - Biosciences | Página 86

Effects of Diazinoxon on Transglutaminase 2 Activity in Amine Incorporation
Thomas O. Gailey

Abstract
Diazinoxon is a bioactive oxide analogue of Diazinon, an organophosphate used in pesticides, known for
acetylcholinesterase inhibition. The transamiding activity of TG2 is linked to many cellular processes, and to
some pathological outcomes. Following studies conducted on TG2 activity with other organophosphates,
effects of Diazinoxon on in vitro transglutaminase activity by biotin cadaverine incorporation assay were
observed. The linear activity phase of TG2 was identified as being a dilution of 1:80 of stock TG2. TG2 aliquots
were incubated with DMSO or DZNO concentration ranging from 5µM to 0.31µM for approximately 15
minutes, after which activity was measured. Data obtained showed decreased TG2 activity with DZNO
incubation at concentration greater than 0.31µM. Following four independent experiments an IC 50 was
calculated with a DZNO concentration of 1.4µM. Concentrations over 2.5µM showed decreasing rate of
inhibition, extrapolation suggests potency of DZNO plateaus after 5µM. Further studies of DZNO, in vitro and in
vivo are required before any definitive conclusion can be reached regarding DZNO specific inhibition of TG2.