TOMSCHY, A and BOHM, G and JAENICKE, R (1994) THE EFFECT OF ION-PAIRS ON THE THERMAL-STABILITY OF D-GLYCERALDEHYDE 3-PHOSPHATE DEHYDROGENASE FROM THE HYPERTHERMOPHILIC BACTERIUM THERMOTOGA-MARITIMA. PROTEIN ENGINEERING, 7 (12). pp. 1471-1478. ISSN 0269-2139,
Full text not available from this repository.Abstract
D-Glyceraldehyde 3-phosphate dehydrogenase from Thermotoga maritima (TmGAPDH) is intrinsically thermostable, exhibiting a thermal transition beyond 105 degrees C. Neither the amino-acid composition nor homology modelling, based on sequence alignment and known 3-D structures of the enzyme from meso- and thermophiles, provide an explanation of the anomalous stability. Recent X-ray data suggest that an increased number of ion pairs is involved. To prove this hypothesis, a number of charged residues contributing to ion pairs in TmGAPDH, but absent in the moderately thermophilic enzyme were altered. Elimination of peripheral ion pairs (E103-K104, E261-R266) was found to be ineffective. Altering a central charge cluster (R10-D47, E314, D*186) led to a drastic decrease in coenzyme binding. As a consequence, guanidine-dependent deactivation is shifted to significantly lower guanidinium chloride (GdmCl) concentrations without altering the denaturation/dissociation profile of the wild type enzyme. Mutants in the S loop (R195D, R195D-D181K) lead to a biphasic profile in the GdmCl-dependent denaturation transition and significant destabilization; at room temperature no subunit dissociation could be observed.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | D-GLYCERALDEHYDE-3-PHOSPHATE DEHYDROGENASE; BACILLUS-STEAROTHERMOPHILUS; PROTEIN STABILITY; LACTOBACILLUS-PLANTARUM; SUBUNIT INTERACTION; ESCHERICHIA-COLI; PYRUVATE OXIDASE; COENZYME BINDING; HEAT-STABILITY; ENZYME; GLYCERALDEHYDE 3-PHOSPATE DEHYDROGENASE; ION PAIRS; STABILITY; THERMOPHILES; THERMOTOGA MARITIMA |
| Depositing User: | Dr. Gernot Deinzer |
| Last Modified: | 19 Oct 2022 08:39 |
| URI: | https://pred.uni-regensburg.de/id/eprint/52963 |
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