Immobilization of Urease from Pigeonpea (Cajanus cajan) on Agar Tablets and Its Application in Urea Assay

Abstract

The gene for the Cu, Zn-superoxide dismutase (SOD) from the yeast Saccharomyces cerevisiae was cloned, characterized, and overexpressed in the methylotrophic Pichia pastoris. The sod gene sequence obtained is 465 bp and encodes 154 amino acid residues. The sod gene sequence was cloned into the pPIC9K vector, yielding pAB22. The linearized pAB22 DNA, digested with restriction enzyme SacI, was transformed into the genome of the GS115 strain of the yeast P. pastoris. The SOD was purified from the cultured yeast by ammonium sulfate precipitation and DEAE-cellulose column chromatography. This relatively simple purification method produced a single band on analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The overexpressed SOD protein was shown to have immunologically biologic activity and to be enzymatically active. The yeast overexpressing Cu, Zn- SOD appeared to be more resistant to oxidative stress such as paraquat, menadione, and heat shock.

Response surface analysis of nano-ureases from Canavalia ensiformis and Cajanus cajan

“…In the present case, lower glycosylation in case of urease from C. ensiformis is responsible for lesser immobilization efficiency than urease from C. cajan (www.brenda-enzymes.org). The immobilization efficiencies of urease obtained from C. ensiformis and C. cajan onto AuNps are significantly higher than previous reports on urease immobilization onto various matrices [9][10][11][12][13][14][15][16][17][21][22][23][24][25][26]. …”

“…Partitioning effects on K m have been discussed in various reports on enzyme immobilization [33][34][35]. Nano-ureases from C. ensiformis and C. cajan have significantly improved kinetic parameters with respect to previous studies on urease immobilization [12][13][14][15][16][17][18][21][22][23][24][25][26].…”

“…It is one of the most desirable matrices for enzyme immobilization due to its very small size, it minimizes diffusional constrains and provides large surface area for enzyme attachment. Urease immobilization is one of the mosteffective ways for its various industrial applications which imparts stability and improvement in physico-chemical parameters [9][10][11][12]. Urease immobilization onto various nano-particles like titanium oxide, iron oxide, glycidyl methacrylate grafted sodium alginate, etc.…”

Immobilization and Characterization of Tannase and its Haze-removing

“…The results showed that the optimum temperature of free tannase was 45 C, whereas that of immobilized tannase was 35 C (Figure 1a).The optimum temperature decreased by 10 C after immobilization. Generally, immobilization may enhance or not change the optimum temperature of enzyme (Neerupma et al, 2006;Mulagalapalli et al, 2007;Makkar, 1982;Roila et al, 2007;Bruno et al, 2005). There are few reports that immobilization decreases the optimum temperature.…”

Urease covalently immobilized on cotton-derived nanocellulose-dialdehyde for urea detection and urea-based multicomponent synthesis of tetrahydro-pyrazolopyridines in water

“… 16 Due to the higher lifetime and stability of chemically bonded enzymes, chemical immobilization (CI) of urease is more feasible 17 than physical adsorption 18 or encapsulation, 19–21 although CI leads to some enzyme activity loss. 22 In this context, the immobilization of urease on cellulose, 9 chitosan, 23 alginate, 24 gelatin, 25 and agar 26 have been tried to achieve urea biosensors. 27,28 Kumar et al 24 prepared the biosensor alginate@urease and compared it with chitosan@urease for urea detection.…”