An Enzyme with High Catalytic Proficiency Utilizes Distal Site Substrate Binding Energy to Stabilize the Closed State but at the Expense of Substrate Inhibition
(2022) In ACS Catalysis 12(5). p.3149-3164- Abstract
- Understanding the factors that underpin the enormous catalytic proficiencies of enzymes is fundamental to catalysis and enzyme design. Enzymes are, in part, able to achieve high catalytic proficiencies by utilizing the binding energy derived from nonreacting portions of the substrate. In particular, enzymes with substrates containing a nonreacting phosphodianion group coordinated in a distal site have been suggested to exploit this binding energy primarily to facilitate a conformational change from an open inactive form to a closed active form, rather than to either induce ground state destabilization or stabilize the transition state. However, detailed structural evidence for the model is limited. Here, we use β-phosphoglucomutase (βPGM)... (More)
- Understanding the factors that underpin the enormous catalytic proficiencies of enzymes is fundamental to catalysis and enzyme design. Enzymes are, in part, able to achieve high catalytic proficiencies by utilizing the binding energy derived from nonreacting portions of the substrate. In particular, enzymes with substrates containing a nonreacting phosphodianion group coordinated in a distal site have been suggested to exploit this binding energy primarily to facilitate a conformational change from an open inactive form to a closed active form, rather than to either induce ground state destabilization or stabilize the transition state. However, detailed structural evidence for the model is limited. Here, we use β-phosphoglucomutase (βPGM) to investigate the relationship between binding a phosphodianion group in a distal site, the adoption of a closed enzyme form, and catalytic proficiency. βPGM catalyzes the isomerization of β-glucose 1-phosphate to glucose 6-phosphate via phosphoryl transfer reactions in the proximal site, while coordinating a phosphodianion group of the substrate(s) in a distal site. βPGM has one of the largest catalytic proficiencies measured and undergoes significant domain closure during its catalytic cycle. We find that side chain substitution at the distal site results in decreased substrate binding that destabilizes the closed active form but is not sufficient to preclude the adoption of a fully closed, near-transition state conformation. Furthermore, we reveal that binding of a phosphodianion group in the distal site stimulates domain closure even in the absence of a transferring phosphoryl group in the proximal site, explaining the previously reported β-glucose 1-phosphate inhibition. Finally, our results support a trend whereby enzymes with high catalytic proficiencies involving phosphorylated substrates exhibit a greater requirement to stabilize the closed active form. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/9408700c-679c-4bdc-b39a-6efc79691915
- author
- Robertson, Angus J. LU ; Cruz-Navarrete, F. Aaron ; Wood, Henry P. ; Vekaria, Nikita ; Hounslow, Andrea M. ; Bisson, Claudine ; Cliff, Matthew J. ; Baxter, Nicola J. and Waltho, Jonathan P.
- publishing date
- 2022-03-04
- type
- Contribution to journal
- publication status
- published
- in
- ACS Catalysis
- volume
- 12
- issue
- 5
- pages
- 3149 - 3164
- publisher
- The American Chemical Society (ACS)
- external identifiers
-
- scopus:85125951993
- ISSN
- 2155-5435
- DOI
- 10.1021/acscatal.1c05524
- language
- English
- LU publication?
- no
- id
- 9408700c-679c-4bdc-b39a-6efc79691915
- date added to LUP
- 2024-01-25 15:50:57
- date last changed
- 2024-01-26 14:00:41
@article{9408700c-679c-4bdc-b39a-6efc79691915,
abstract = {{Understanding the factors that underpin the enormous catalytic proficiencies of enzymes is fundamental to catalysis and enzyme design. Enzymes are, in part, able to achieve high catalytic proficiencies by utilizing the binding energy derived from nonreacting portions of the substrate. In particular, enzymes with substrates containing a nonreacting phosphodianion group coordinated in a distal site have been suggested to exploit this binding energy primarily to facilitate a conformational change from an open inactive form to a closed active form, rather than to either induce ground state destabilization or stabilize the transition state. However, detailed structural evidence for the model is limited. Here, we use β-phosphoglucomutase (βPGM) to investigate the relationship between binding a phosphodianion group in a distal site, the adoption of a closed enzyme form, and catalytic proficiency. βPGM catalyzes the isomerization of β-glucose 1-phosphate to glucose 6-phosphate via phosphoryl transfer reactions in the proximal site, while coordinating a phosphodianion group of the substrate(s) in a distal site. βPGM has one of the largest catalytic proficiencies measured and undergoes significant domain closure during its catalytic cycle. We find that side chain substitution at the distal site results in decreased substrate binding that destabilizes the closed active form but is not sufficient to preclude the adoption of a fully closed, near-transition state conformation. Furthermore, we reveal that binding of a phosphodianion group in the distal site stimulates domain closure even in the absence of a transferring phosphoryl group in the proximal site, explaining the previously reported β-glucose 1-phosphate inhibition. Finally, our results support a trend whereby enzymes with high catalytic proficiencies involving phosphorylated substrates exhibit a greater requirement to stabilize the closed active form.}},
author = {{Robertson, Angus J. and Cruz-Navarrete, F. Aaron and Wood, Henry P. and Vekaria, Nikita and Hounslow, Andrea M. and Bisson, Claudine and Cliff, Matthew J. and Baxter, Nicola J. and Waltho, Jonathan P.}},
issn = {{2155-5435}},
language = {{eng}},
month = {{03}},
number = {{5}},
pages = {{3149--3164}},
publisher = {{The American Chemical Society (ACS)}},
series = {{ACS Catalysis}},
title = {{An Enzyme with High Catalytic Proficiency Utilizes Distal Site Substrate Binding Energy to Stabilize the Closed State but at the Expense of Substrate Inhibition}},
url = {{http://dx.doi.org/10.1021/acscatal.1c05524}},
doi = {{10.1021/acscatal.1c05524}},
volume = {{12}},
year = {{2022}},
}