title: Immobilized-metal-chelate regenerable carriers: (I). Adsorption and stability of penicillin G amidohydrolase from Escherichia coli.
abstract: 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 immobilization of PGA, 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.
authors: GBF-National Research Center for Biotechnology, Braunschweig, Germany.
authors: F B
authors: FB
authors: Anspach
authors: G
authors: G
authors: Altmann-Haase
mesh_terms: D000327:Adsorption; D002384:Catalysis; D002614:Chelating Agents; D003300:Copper; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology*; D010399:Penicillin Amidase / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D002614:Chelating Agents; D004800:Enzymes, Immobilized; D003300:Copper; D010399:Penicillin Amidase