title: Preparation of cross-linked enzyme aggregates of trehalose synthase via co-aggregation with polyethyleneimine.
abstract: Trehalose synthase (TreS) from Meiothermus ruber was co-aggregated with polyethyleneimine (PEI) and precipitated with polyethylene glycol (PEG), followed by cross-linking with glutaraldehyde to obtain TreS-polyethyleneimine cross-linked enzyme aggregates (termed as CLEAs-PEI-PEG). The TreS solution at 0.5 mg mL(-1) protein concentration, with PEI at a mass ratio of 1:0.8 (enzyme/PEI, w/w) and 25 % (w/v) PEG concentration were found to be most adequate for the co-aggregation of TreS. CLEAs-PEI-PEG was most active with glutaraldehyde at a mass ratio of 1:0.5 (enzyme/glutaraldehyde, w/w) to cross-link the co-aggregates. The CLEAs-PEI-PEG prepared in this work had an optimum pH of 6.5 and optimum temperature of 60 °C. For lower concentrations of enzyme, using PEI could enhance the cross-linking efficiency of TreS. The thermal stability and pH tolerance of CLEAs-PEI-PEG were significantly improved. Scanning electron microscopy revealed that the main structure of CLEAs-PEI-PEG showed scaffolding morphology which was constituted by structured ball-like particles with a size of 1-2.5 μm in diameter.
authors.affiliation: Tianjin Institute of Forestry and Pomology, Tianjin Academy of Agricultural Science, Tianjin, 300384, China.
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Zheng
authors.forename: Ying
authors.initials: Y
authors.lastname: Chen
authors.forename: Liwei
authors.initials: L
authors.lastname: Yang
authors.forename: Mingchun
authors.initials: M
authors.lastname: Li
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
mesh_terms: D055162:Biocatalysis; D003432:Cross-Linking Reagents / Q000494:pharmacology*; D034301:Deinococcus / Q000201:enzymology; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism; D005964:Glucosyltransferases / Q000737:chemistry* / Q000378:metabolism; D005976:Glutaral / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D011092:Polyethylene Glycols / Q000737:chemistry; D011094:Polyethyleneimine / Q000737:chemistry*; D013696:Temperature
chemical_list: D003432:Cross-Linking Reagents; D004800:Enzymes, Immobilized; D011092:Polyethylene Glycols; D011094:Polyethyleneimine; D005964:Glucosyltransferases; C099692:trehalose synthase; D005976:Glutaral