Anti-CAT monoclonal antibody, clone 737DU5.4.9

Several cereal grains contain a mycotoxin food contaminant called deoxynivalenol (DON), which presents a significant health risk as it is one of the most commonly found mycotoxins. The current paper examines the ameliorative effect of mangiferin (MAN) in vascular endothelial cells induced through activating the Nrf2 signalling pathway on dietary DON-induced oxidative changes. The study infers that the intercellular reactive oxygen species (ROS) levels and malondialdehyde decrease due to MAN. Other effects include in human umbilical vein endothelial cells (HUVECs), the oxidative stress-induced cell damage is reduced due to protective effects and superoxide dismutase (SOD), and catalase (CAT) activities also reveal an improvement. In HUVECs, the Nrf2-regulated antioxidant enzyme genes' expression is activated by Nrf2 nuclear translocation induction and this activity suppresses the oxidative stress damage. The genes in HUVECs include HO-1 and NQO1. Moreover, in HUVECs, the nucleus translocation of Nrf2 reduces the Nrf2, HO-1, whereas NQO1 expression decreases the cytoprotective effects against oxidative stress reduce with the rejection of Nrf2 with siRNA. This paper pioneers in inferring that oxidative stress-induced HUVECs' cell injury is suppressed by MAN through Nrf2, signalling pathway activation.

Human D-amino acid oxidase (DAO) is a flavoenzyme that is implicated in neurodegenerative diseases. We investigated the impact of replacement of proline with leucine at Position 219 (P219L) in the active site lid of human DAO on the structural and enzymatic properties, because porcine DAO contains leucine at the corresponding position. The turnover numbers (k(cat)) of P219L were unchanged, but its K-m values decreased compared with wild-type, leading to an increase in the catalytic efficiency (k(cat)/K-m). Moreover, benzoate inhibits P219L with lower K-i value (0.7-0.9 mu M) compared with wild-type (1.2-2.0 mu M). Crystal structure of P219L in complex with flavin adenine dinucleotide (FAD) and benzoate at 2.25 angstrom resolution displayed conformational changes of the active site and lid. The distances between the H-bond-forming atoms of arginine 283 and benzoate and the relative position between the aromatic rings of tyrosine 224 and benzoate were changed in the P219L complex. Taken together, the P219L substitution leads to an increase in the catalytic efficiency and binding affinity for substrates/inhibitors due to these structural changes. Furthermore, an acetic acid was located near the adenine ring of FAD in the P219L complex. This study provides new insights into the structure-function relationship of human DAO.