Abstract
A series of isotope edited IR measurements, both static as well as temperature jump relaxation spectroscopy, are performed on lactate dehydrogenase (LDH) to determine the ensemble of structures available to its Michaelis complex. There clearly has been a substantial reduction in the number of states available to the pyruvate substrate (as modeled by the substrate mimic, oxamate) and NADH when bound to protein compared to dissolved in solution, as determined by the bandwidths and positions of the critical C2=O band of the bound substrate mimic and the C4-H stretch of the NADH reduced nicotinamide group. Moreover, it is found that a strong ionic bond (characterized by a signature IR band discovered in this study) is formed between the carboxyl group of bound pyruvate with (presumably) Arg171, forming a strong "anchor" within the protein matrix. However, conformational heterogeneity within the Michaelis complex is found that has an impact on both catalytic efficiency and thermodynamics of the enzyme.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 7670-7678 |
| Number of pages | 9 |
| Journal | Journal of Physical Chemistry B |
| Volume | 115 |
| Issue number | 23 |
| DOIs | |
| State | Published - Jun 16 2011 |
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ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Materials Chemistry
- Surfaces, Coatings and Films
Cite this
Conformational heterogeneity within the Michaelis complex of lactate dehydrogenase. / Deng, Hua; Vu, Dung V.; Clinch, Keith; Desamero, Ruel; Dyer, R. Brian; Callender, Robert.
In: Journal of Physical Chemistry B, Vol. 115, No. 23, 16.06.2011, p. 7670-7678.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Conformational heterogeneity within the Michaelis complex of lactate dehydrogenase
AU - Deng, Hua
AU - Vu, Dung V.
AU - Clinch, Keith
AU - Desamero, Ruel
AU - Dyer, R. Brian
AU - Callender, Robert
PY - 2011/6/16
Y1 - 2011/6/16
N2 - A series of isotope edited IR measurements, both static as well as temperature jump relaxation spectroscopy, are performed on lactate dehydrogenase (LDH) to determine the ensemble of structures available to its Michaelis complex. There clearly has been a substantial reduction in the number of states available to the pyruvate substrate (as modeled by the substrate mimic, oxamate) and NADH when bound to protein compared to dissolved in solution, as determined by the bandwidths and positions of the critical C2=O band of the bound substrate mimic and the C4-H stretch of the NADH reduced nicotinamide group. Moreover, it is found that a strong ionic bond (characterized by a signature IR band discovered in this study) is formed between the carboxyl group of bound pyruvate with (presumably) Arg171, forming a strong "anchor" within the protein matrix. However, conformational heterogeneity within the Michaelis complex is found that has an impact on both catalytic efficiency and thermodynamics of the enzyme.
AB - A series of isotope edited IR measurements, both static as well as temperature jump relaxation spectroscopy, are performed on lactate dehydrogenase (LDH) to determine the ensemble of structures available to its Michaelis complex. There clearly has been a substantial reduction in the number of states available to the pyruvate substrate (as modeled by the substrate mimic, oxamate) and NADH when bound to protein compared to dissolved in solution, as determined by the bandwidths and positions of the critical C2=O band of the bound substrate mimic and the C4-H stretch of the NADH reduced nicotinamide group. Moreover, it is found that a strong ionic bond (characterized by a signature IR band discovered in this study) is formed between the carboxyl group of bound pyruvate with (presumably) Arg171, forming a strong "anchor" within the protein matrix. However, conformational heterogeneity within the Michaelis complex is found that has an impact on both catalytic efficiency and thermodynamics of the enzyme.
UR - http://www.scopus.com/inward/record.url?scp=79958861452&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79958861452&partnerID=8YFLogxK
U2 - 10.1021/jp2015929
DO - 10.1021/jp2015929
M3 - Article
C2 - 21568287
AN - SCOPUS:79958861452
VL - 115
SP - 7670
EP - 7678
JO - Journal of Physical Chemistry B Materials
JF - Journal of Physical Chemistry B Materials
SN - 1520-6106
IS - 23
ER -