Immobilized-metal-chelate regenerable carriers: (I) . Adsorption and stability of penicillin G amidohydrolase from Escherichia coli
Anspach, F.B.; Altmann-Haase, G.
Biotechnology and Applied Biochemistry 20(3): 313-322
1994
ISSN/ISBN: 0885-4513 PMID: 7818802 Document Number: 428307
Penicillin G amidohydrolase (PGA) was immobilized on Cu(II)-chelate regenerable sorbents. A long spacer was essential for binding, such as bisoxirane in the case of Sepharose 4B or glycidoxypropyltrimethoxysilane in the case of silica-based carriers. The stability of the PGA-carrier was determined both by the interaction forces between PGA and the metal-chelate sorbent and the presence of penicillin G (Pen G). The force of interaction between the enzyme and the metal-chelate sorbent was low, and Pen G competed for binding sites at high concentrations. The carrier with a small pore size demonstrated diffusion restrictions during immunobilization of PCA resulting in low activities of the immobilized enzyme. This carrier could not be completely regenerated. Carriers with an average pore size of 55 nm or larger displayed fewer diffusion restrictions. The corresponding Cu(II)-chelate sorbents were regenerated several times.