A Study of Soluble and Immobilized soybean urease on green synthesized gold nanoparticles and its application

Abstract

Ureases (urea amid hydrolase, EC 3.5.1.5) are the most proficient enzyme known to newlinedate and are widely distributed in plants, fungi and bacteria. It is a metalloenzyme newlinewhich is nickel-dependent and its function is to catalyze the hydrolysis of urea into newlineammonia and carbon dioxide. Jack bean (Canavalia ensiformis) urease is the best newlinestudied plant urease and identified as the first nickel metalloenzyme and also was the newlinefirst enzyme to be crystallized. In plants, urease plays a pivotal role in urea nitrogen newlinecycle, acts as defense protein in systemic nitrogen transport pathways, is responsible newlinefor accumulation pattern of the proteins during seed maturation and also functions in newlinethe utilization of seed protein reserves during germination along with arginase. On the newlineother hand, bacterial ureases are involved in formation of infection stones and newlinecontribute to the pathogenesis of urolithiasis, pyelonephritis, ammonia and hepatic newlineencephalopathy, etc. newlineClinically, this enzyme is used in quantitative determination of urea in pathological newlineconditions as well as determination of blood urea concentration. In industries, acid newlineureases are used for elimination of urea from alcoholic beverages, to check newlineadulteration in milk, etc. Urease conductometric biosensors are used for detection of newlineheavy metals in ground water. newlineHowever, use of free enzymes have some major drawbacks such as thermal stability, newlinesusceptibility to attack by proteases, activity inhibition, high sensitivity to denaturing newlineagents, the impossibility of separating and reusing free catalyst at the end of the newlinereaction, etc. To overcome these limitations, the most successful technique is enzyme newlineimmobilization in which movement of the enzyme is restricted by attaching to an inert newlinematerial which provides an increased resistance for the immobilized enzyme to the newlinechanges in newline