Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.17.1.4 (xanthine dehydrogenase)
 1,236 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The distribution of the Mo-enzymes aldehyde oxidase (AO; EC 1.2.3.1) xanthine dehydrogenase (XDH; EC 1.2.1.37) and nitrate reductase (NAD(P)H NR; EC 1.6.6.1-2) was studied along the longitudinal and transversal axes of maize (Zea mays L. cv. Jubily) nodal roots as affected by nitrogen sources and salinity. Activities of the Mo-enzymes were considerably enhanced under mild saline conditions. The activities of AO and XDH increased following addition of ammonium to the nutrient solution. Immunoblot analysis with antibodies raised against maize AO protein revealed increased levels of AO proteins in root tips of ammonium fed plants. Application of salinity to nitrate fed plants did not affect the enzyme protein level, although it enhanced the activity of the Mo-hydroxylases. The specific activities of the Mo-enzymes were the highest in root tips (0-1 cm segments) while on the transversal axis maximal activity was observed in the stele or vascular cylinder. Activity staining of AO after native PAGE of root extracts revealed four bands of AO proteins (AO1-4) capable of oxidizing a number of aliphatic and aromatic aldehydes. Increased AO activity in maize nodal roots grown with ammonium, and salinity were observed mainly at the AO3 and AO4 bands. Tips and stele contained primarily AO3 and AO4, and only traces of AO1 and AO2. SDS-PAGE of root extracts followed by Western blots revealed, besides the major 150 kD subunit of AO, two polypeptides with molecular masses of 72 and 85 kD located specifically in the cortex. Part of the polymorphism of AO in plant roots may be related to the allocation of distinct isoforms to different regions of the root, although the specific metabolic roles of the different bands have not been established.
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PMID:Distribution of the Mo-enzymes aldehyde oxidase, xanthine dehydrogenase and nitrate reductase in maize (Zea mays L.) nodal roots as affected by nitrogen and salinity. 1077 39

Xanthine dehydrogenase (XDH), also known as xanthine oxidoreductase (XOR), has long been recognized as the key enzyme in the catabolism of purines, oxidizing hypoxanthine into xanthine and then xanthine into uric acid. In addition, levels of XDH expression are reportedly related to the prognosis of patients with malignant tumors, though the relationship between the clinicopathological features of lung cancer and XDH is not fully understood. We therefore used semiquantitative real-time reverse transcription polymerase chain reaction to assess expression of XDH mRNA in tumor samples from 88 patients with adenocarcinoma of the lung. We then correlated XDH mRNA levels with known clinicopathological factors. We found that the 5-year overall survival rate among patients strongly expressing XDH was significantly poorer than among those expressing lower levels of XDH (P < 0.001; log-rank test). Normal lung tissue does not express XDH. Multivariate Cox proportional hazard analyses revealed that being male (hazard ratio, 3.14; 95 % confidence interval (CI), 1.45-7.07; P = 0.004), nodal metastasis positivity (hazard ratio, 5.74; 95 % CI, 1.94-19.3; P = 0.001), and high XDH expression (hazard ratio, 2.33; 95 % CI, 1.11-5.02; P = 0.026) were all independent factors affecting 5-year disease-free survival. In conclusion, high tumoral XDH expression is an independent predictor of a poor prognosis in patients with adenocarcinoma of the lung.
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PMID:Acquired xanthine dehydrogenase expression shortens survival in patients with resected adenocarcinoma of lung. 2267 77