title: Lipoamide dehyrogenase immobilized on porous glass.
abstract: Lipoamide dehydrogenase (NADH:lipoamide oxidoreductase, EC 1.6.4.3) isolate from pig heart and Escherichia coli was covalently coupled by both diazonium and amide bonds to controlled pore glass beads (96% silica). When the enzyme was immobilized in the presence of NAD+, the enzyme no longer exhibited its normal requirement for NAD+ for full activity. If the immobilized enzyme was then treated with NADase, the requirement for NAD+ was restored. Enzyme immobilized in the absence of NAD+ exhibited normal NAD+ dependence both prior to an after NADase treatment. These results are discussed in terms of co-immobilization of NAD+ at or near the allosteric site of the enzyme.
mesh_terms: D000495:Allosteric Site; D000818:Animals; D001665:Binding Sites; D008058:Dihydrolipoamide Dehydrogenase / Q000378:metabolism*; D004800:Enzymes, Immobilized / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology; D005898:Glass; D007700:Kinetics; D009206:Myocardium / Q000201:enzymology; D009243:NAD / Q000494:pharmacology; D009244:NAD+ Nucleosidase / Q000494:pharmacology; D011485:Protein Binding; D013552:Swine
chemical_list: D004800:Enzymes, Immobilized; D009243:NAD; D008058:Dihydrolipoamide Dehydrogenase; D009244:NAD+ Nucleosidase