Uricase from leaves: its purification and characterization from three different higher plants

Abstract

Uricase (urate: oxygen oxidoreductase, EC 1.7.3.3) from leaves of chickpea (Cicer arietimum L.), broad bean (Vicia faba major L.), and wheat (Triticum aestivum L.) has been puri®ed to electrophoretic homogeneity by a procedure which includes xanthine-agarose anity chromatography as the main step. Puri®cation factors of 74 000±83 000 and recoveries of 80±90% were achieved. Puri®ed preparations had speci®c activities between 600 and 800 nkat á mg protein A1 (turnover numbers between 4400 and 6400 min A1 ). The three plant uricases were found by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to be tetramers of similar molecular mass (120±130 kDa) and to have identical or similar-sized subunits (32±34 kDa). They also had a similar optimum pH (9±9.5) and showed a hyperbolic kinetics with K m values from 9±24 lM. All of them showed similar responses to putative activators/ inhibitors. Oxonate, xanthine and, to a lesser extent, neocuproin inhibited uricase activity, whereas allantoin, ammonium, citrulline and glutamine did not. The three leaf uricases lacked catalase activity and were not activated by cadaverine. None of the three plant enzymes cross-reacted with anti-uricase monoclonal antibodies from soybean nodules or anti-uricase polyclonal antibodies from Chlamydomonas reinhardtii or rat liver. These results are consistent with the view that uricase in plants is probably a unique enzyme which is expressed at very low level in leaves.

Modified colorimetric assay for uricase activity and a screen for mutant Bacillus subtilis uricase genes following StEP mutagenesis

“…This enzyme is found in mammals [1,2], plants [3], fungi [4], yeasts [5][6][7] and bacteria [8]. Uric acid, the primary end-product of purine metabolism, is present in biological fluids, including blood and urine [9].…”

Optimum conditions for uricase enzyme production by Gliomastix gueg

“…It was first found in bovine kidney. Various natural sources such as bacteria (Mansour et al, 1996), fungi (Farley and Santosa, 2002) and eukaryotic cells (Montalbini et al, 1997) have also been found to be uricase producers. The first important application discovered for uricase was in clinical biochemistry as a diagnostic reagent for measurement of uric acid in blood and other biological fluids (Adamek et al, 1989).…”

<b><i>Arxula adeninivorans</i></b> Recombinant Urate Oxidase and Its Application in the Production of Food with Low Uric Acid Content

“…Urate oxidase is an inducible enzyme that is found in a variety of organisms such as bacteria [Arima and Nose, 1968;Lotfy, 2008], fungi [Franke and Krieg, 1952], yeast [Liu et al, 1994], algae [Alamillo et al, 1991], plants [Montalbini et al, 1997] and is expressed in mammalian peroxisomes in specific tissues [Antonenkov and Panchenko, 1978;Rajoka et al, 2006]. It is however absent in higher primates (hominoids and some New World monkeys), birds, terrestrial reptiles and most insects [Keebaugh and Thomas, 2010;Keilin, 1959;Oda et al, 2002].…”