Enzyme immobilisation on poly-l-lysine-containing calcium phosphate particles for highly sensitive glucose detection

Abstract

The as-synthesised poly-l-lysine-containing HAp with high enzyme stability could be a candidate for a glucose sensor with high sensitivity.

Preparation of Protein–Peptide–Calcium Phosphate Composites for Controlled Protein Release

“…These composites exhibited highly selective adsorption characteristics for various proteins, and the amount of protein loading on the composites was found to vary depending on the structures of the peptides. In addition, the enzymes adsorbed on the composites exhibited higher or comparable catalytic activities to those of free enzymes in solution [29]. As an extension of our previous work, the in situ encapsulation of proteins during the preparation of a peptide-CaP composite was developed for various biological applications.…”

“…In addition, there were no significant differences in the morphologies of the protein-peptide-CaP composites in comparison with CaP containing no protein. In our previous study [29], αpLys-CaP composites were obtained with rod-like morphologies, formed using a similar synthetic procedure to that described in this work. The protein molecules were found to be affected by the morphologies of the sheet-like CaP materials.…”

“…We also designed α-helix and β-sheet peptide templates containing L-glutamic acid for CaP mineralization [28], where the prepared CaP-peptide composites exhibited protein adsorption with high selectivity for basic proteins (e.g., cytochrome c and lysozyme). Very recently, we observed [29] that glucose oxidase immobilized on poly(L-lysine)-containing CaP particles exhibited high activity and that their relative activity remained at approximately 70% after ten cycles. In addition, poly (L-glutamic acid)-containing CaP showed high adsorption for the basic protein avidin and its effective binding to biotin, with a theoretical value of four (biotin/avidin molecular ratio) [30].…”

Efficient enzyme encapsulation inside sol-gel silica sheets prepared by poly-L-lysine as a catalyst

“…The conformational changes of GOx immobilized on a silica sheet were evaluated using 8-anilino-1-naphthalenesulfonic acid (ANS), which is a popular fluorescence probe that is typically used to investigate the conformational changes of proteins [50]. For analysis, the samples were mixed at the volume ratio of 1/ 1 (v/v) with a GOx solution in both composite and native states (40 µg/500 mL)/ANS solution (40 µg/ 500 mL).…”

“…Enzyme-based biosensors are used in an increasing number of clinical, environmental, and biochemical applications [39][40][41][42][43][44][45]. Redox enzymes, such as glucose oxidase (GOx), do not exchange electrons with simple metal electrodes [46][47][48][49][50][51]. Historically, electrical communication between enzyme and electrode has been achieved using diffusing mediators.…”