Improving the Stability of Immobilized Penicillin G Acylase via the Modification of Supports With Ionic Liquids

Abstract

With the aim of improving the stability of penicillin G acylase (PGA), functional ionic liquids (ILs) were used to modify the surface chemistry of the supports on which they were physically adsorbed. Four kinds of ILsspecifically, 1-methyl-3-(triethoxysilylpropyl)-imidazolium salts, with Cl − , BF 4 − , PF 6 − , and Tf 2 N − as the anions (IL-Cl − , BF 4 − , PF 6 − , and Tf 2 N − , respectively)were used to tune the hydrophilic or hydrophobic properties of the ILs. The synthesized ILs were first immobilized on magnetic silica nanoparticles (Fe 3 O 4 /SiO 2 ), and the composite material (Fe 3 O 4 /SiO 2 −IL) was then applied to immobilize PGA via physical adsorption. The amount of protein loading, the specific activity, the immobilization yield, and the stability of immobilized PGA were investigated to evaluate the effects of the ILs on the PGA immobilization. The results showed that PGA immobilized on Fe 3 O 4 /SiO 2 −ILs was more stable than that immobilized on Fe 3 O 4 /SiO 2 with no IL modification. Among the four kinds of ILs tested, the hydrophilic ILs (IL-Cl − , and IL-BF 4 − ) were superior to the hydrophobic ones (IL-PF 6 − , and IL-Tf 2 N − ) for PGA immobilization. The reusability of the immobilized PGA on Fe 3 O 4 /SiO 2 −IL (BF 4 −) was evaluated; a high residual activity (70% of the initial activity) was observed after 9 consecutive operation cycles under the experimental conditions. This activity was 1.8 times higher than that of immobilized PGA on naked Fe 3 O 4 /SiO 2 (40%).

Synthesis of magnetic nanoparticles with an IDA or TED modified surface for purification and immobilization of poly-histidine tagged proteins

“…q e and k 1 can be used to calculate the slope and intercept of t/q t vs. t. The pseudo-second order kinetic model can be used to describe the kinetics of protein adsorption to the surface of carrier. [72][73][74] The k 1 , q e , and v 0, of Ni-FS-IDA or Ni-FS-ECH-IDA MNPs binding to DspB are similar and both are higher than that of Ni-FS-TED MNPs. The v 0 of Ni-FS-IDA or Ni-FS-ECH-IDA MNPs are almost 3 times higher than that of Ni-FS-TED MNPs.…”

Design of Efficient Noble Metal Free Copper‐Promoted Nickel‐Ceria‐Zirconia Nanocatalyst for Bio‐Fuel Upgrading

“…The incorporation of Ni 2 + into the ceria-zirconia structure was proven to enhance activity in hydrogenation reaction with retarded deactivation to the single ceria and other commercial supports. [24,25] Introduction of second metals such as Fe, Cu, Co, and Pd to Ni further enhanced catalytic performances, creating strong metal support interactions and redox properties of the catalysts. Q. Guo et al reported that HDO efficiency of algae bio-oils over bimetallic NiÀCu/ZrO 2 catalysts can be tuned with the amount of Cu.…”

Pt and Pd Nanoparticles Immobilized on Amine-Functionalized Hypercrosslinked Porous Polymer Nanotubes as Selective Hydrogenation Catalyst for α,β-Unsaturated Aldehydes

“…Hence, a large number of heterogeneous supports e. g. porous silica, [3] nanoporous organic polymers (POPs), [4] metal oxides, [5] N-doped activated carbon, [6] amorphous carbon [7] etc. are reported, which shows quite promise and potential in anchoring metal NPs for catalysis, but hierarchical micromesoporous support with uniform hollow nanostructure could be more promising.…”