Urease immobilized on modified polysulphone membrane: Preparation and properties

Cotton gauze bandage: a support for protease immobilization for use in biomedical applications

“…Upon immobilization, the covalent coupling of the protein molecule to the support significantly reduced its freedom to undergo the conformational changes that lead to denaturation (Arica et al, 1995;Bayramoglu et al, 2003). Similar results have been observed for trypsin and other proteases covalently immobilized to other supports like soap-free P(MMA-EA-AA) latex particles (Kang et al, 2005), a chitosan membrane (Krajewska et al, 1990) and a modified polysulphone membrane (Pozniak et al, 1995).…”

Urease immobilized on nylon: preparation and properties

“…Similar observation was made by Iyengar and Rao [17] using urease bound to chitin and by Lai and Tabatabai [18]. Results obtained by Pozniak et al [19] using urease bound to modi®ed polysulphone membrane showed that the free urease (Type III) was immobilized on the membrane. The increased adsorption of protein with increasing temperature was reported to be due to the unfolding of the protein molecules, having more functional groups available for binding to the support [20].…”

“…Effect of enzyme concentration on relative activity of urease immobilized using nylon tubes and glutaraldehyde [14] showed that the immobilized urease had a higher sensitivity to temperature than the free enzyme. These results agree with those reported by Body and Wortland [21] for urease bound on HDTA-smectite and Pozniak et al [19] but are in contrast to the ®ndings of Sundaram and Crook [22]. The latter found that jackbean urease adsorbed on kaolinite was as thermally stable as the free enzyme.…”

“…It was reported that urease had different pH optima ranging from 6.4 to 7.4 depending on the type of buffer used [25]. As reported by Pozniak [19], Iyengar and Rao [17] and Weetall and Hersh [26], when bound to a support, the optimum pH of urease shifted towards the more acidic side. However, when urease was activated with formaldehyde [27], the pH optimum shifted towards the alkaline side.…”

Postsynthesis modification of a cellulose acetate ultrafiltration membrane for applications in water and wastewater treatment

“…Increasing hydrophilicity leads to the formation of hydrophilic channels that increase rates of water permeation [29]. Modification methods that have been investigated include ion-beam irradiation [30], plasma treatment or grafting [31,32], UV-induced grafting [33], chemical sulfone enrichment [34], chemical dehydrofluorination by alkaline solution [35], coating temperature-sensitive polymeric brushes [36], grafting with pH-and ionic strength-sensitive polymeric brushes [37,38], ␥-irradiation-induced grafting [39], physical adsorption of water soluble polymers [26], formation of Langmuir-Blodgett films [40], thermal grafting of a hydrophilic polymeric surface coating [41], and photografting with UV irradiation [42].…”