Biotechnology and Bioengineering, Vol.81, No.3, 356-369, 2003
Kinetic locking-on and auxiliary tactics for bioaffinity purification of NADP(+)-dependent dehydrogenases using N-6-linked immobilized NADP(+) derivatives: Studies with mammalian and microbial glutamate dehydrogenases
This study is concerned with the development and application of kinetic locking-on and auxiliary tactics for bioaffinity purification of NADP(+)-dependent dehydrogenases, specifically (1) the synthesis and characterization of highly substituted W-linked immobilized NADP(+) derivatives using a rapid solid-phase modular approach; (2) the evaluation of the N-6-linked immobilized NADP(+) derivatives for use with the kinetic locking-on strategy for bioaffinity purification of NADP(+)-dependent dehydrogenases: Model bioaffinity chromatographic studies with glutamate dehydrogenase from bovine liver (GDH with dual cofactor specificity, EC 1.4.1.3) and glutamate dehydrogenase from Candida utilis (GDH which is NADP(+)-specific, EC 1.4.1.4); (3) the selection of an effective "stripping ligand" for NADP(+)-dehydrogenase bioaffinity purifications using N-6-linked immobilized NADP(+) derivatives in the locking-on mode; and (4) the application of the developed bioaffinity chromatographic system to the purification of C. utilis GDH from a crude cellular extract. Results confirm that the newly developed N-6-linked immobilized NADP(+) derivatives are suitable for the one-step bioaffinity purification of NADP(+)-dependent GDH provided that they are used in the locking-on mode steps are taken to inhibit alkaline phosphatase activity in crude cellular extracts, and 2',5'-ADP is used as the stripping ligand during chromatography. The general principles described here are supported by a specific sample enzyme purification; the purification of C. utilis GDH to electrophoretic homogeneity in a single bioaffinity chromatographic step (specific activity, 9.12 mumol/min/mg; purification factor, 83.7; yield 88%). The potential for development of analogous bioaffinity systems for other NADP(+)-dependent dehydrogenases is also discussed. (C) 2003 Wiley Periodicals, Inc.
Keywords:glucose-6-phosphate dehydrogenase;glutamate dehydrogenase;bovine liver;Candida utilis;kinetic locking-on strategy;N-6-linked immobilized NADP(+)