Polyethyleneimine–protein interactions and implications on protein stability

Immobilization of the urease on eggshell membrane and its application in biosensor

“…In one review, it was reported that, how PEI with the highest concentration of amino groups, has found acceptance as a carrier in a number of industrial immobilized biosystems [45]. In other review, Mazzaferro et al [46] has reported the polyethylenimine-protein interactions and implications on protein stability. Polymers with amino pendant groups have been well accepted as suitable enzyme carriers.…”

Polyethyleneimine coating of magnetic particles increased the stability of an immobilized diglycosidase

“…Considering the pKa values of branched PEI (4.5 for primary, 6.7 for secondary, and 11.6 for tertiary amine groups), it is reasonable to guess that at pH values ≈5 and below, the polymer PEI will exist in its protonated form . It is known that PEI forms complexes with acidic proteins due to electrostatic forces and the binding of enzymes onto composites with flexible polymers containing a high density of ion exchange moieties would promote a strong adsorption to the detriment of protein stability . Therefore, it was expected that α‐rhamnosyl‐β‐glucosidase (isoelectric point, 5.7) would interact with PEI in the operational conditions of hesperidin hydrolysis.…”

Characterization of chymotrypsin–ι-carrageenan complex in aqueous solution: A solubility and thermodynamical stability study

“…Previous reports have demonstrated that polyelectrolytes influence the enzymatic activity because they induce a modification of the secondary and tertiary protein structure [20,21]. Chy at constant concentration (0.5 mg/ml) was incubated for 30 min in media of increasing Car concentrations (from 0 to 0.02%, w/v) at the pH of the enzyme maximal activity (8.2).…”