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ESR investigations of free and immobilized glutamate dehydrogenase
Author(s) -
O'Connor Kim C.,
Bailey James E.
Publication year - 1989
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.260340114
Subject(s) - glutamate dehydrogenase , chemistry , biochemistry , glutamate receptor , dehydrogenase , enzyme , receptor
The structure of bovine liver glutamate dehydrogenase was examined with 2,2,6,6‐tetramethyl‐4‐oxopiperidine‐1‐oxyl (TEMPO I) and 4‐((4‐(chloromercurio)benzoyl) amino)‐2, 2, 6, 6‐tetramethyl‐1‐piperidinyloxy (TEMPO II). ESR spectra from TEMPO I show that enzyme structure in the vicinity of this spin label was not distorted during immobilization to a Sepharose support. Deactivation studies with pyridoxal 5′‐phosphate indicate that immobilization did not expose additional binding sites to TEMPO I. Spectra from TEMPO II reveal that immobilization profoundly altered conformational change induced by α‐ketoglutarate and suppressed that induced by GTP and NADPH. This structural investigation provides insight into the altered kinetic properties of Sepharose‐immobilized glutamate dehydrogenase and suggests a fundamental difference between monomers and allosteric oligomers in their structural response to immobilization.