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Craig DB, Malhi S, Ahmad B, Breckman K, Patel A. Electrophoretic mobility of individual molecules of alkaline phosphatase. Biochem Cell Biol 2022; 100:349-356. [PMID: 36043529 DOI: 10.1139/bcb-2021-0503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The electrophoretic mobilities and catalytic rates of individual molecules of bovine intestinal alkaline phosphatase were determined in CHES and borate buffers of identical pH using a capillary electrophoresis based method. Both properties were found to be heterogeneous. In the presence of CHES, the mobility and rate were found to be -1.9 ± 0.2 × 10-9 m2 V-1 s-1 and 9.8 ± 7.4 × 104 min-1 (N = 38), respectively. In the presence of borate, the mobility and rate were found to be -6.9 ± 0.5 × 10-9 m2 V-1 s-1 and 2.0 ± 1.3 × 104 min-1 (N = 41), respectively. The means and variances for both properties were found to differ significantly between the two buffers. The difference in average mobility was attributed to an increase in negative charge caused by borate complexing with the carbohydrate moieties attached to the enzyme. The difference in variance was attributed to heterogeneous complexation with borate due to heterogeneity in the glycosylation. The differences in mean values for the catalytic rate were attributed to the inhibitory effect of borate and the difference in variance may suggest that the KI of this binding may also be heterogeneous.
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Affiliation(s)
- Douglas B Craig
- Chemistry Department, University of Winnipeg, Winnipeg, MB, Canada
| | - Simrat Malhi
- Chemistry Department, University of Winnipeg, Winnipeg, MB, Canada
| | - Basit Ahmad
- Chemistry Department, University of Winnipeg, Winnipeg, MB, Canada
| | | | - Ankoor Patel
- Chemistry Department, University of Winnipeg, Winnipeg, MB, Canada
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Park SJ, Song S, Jeong IC, Koh HR, Kim JH, Sung J. Nonclassical Kinetics of Clonal yet Heterogeneous Enzymes. J Phys Chem Lett 2017; 8:3152-3158. [PMID: 28609615 DOI: 10.1021/acs.jpclett.7b01218] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Enzyme-to-enzyme variation in the catalytic rate is ubiquitous among single enzymes created from the same genetic information, which persists over the lifetimes of living cells. Despite advances in single-enzyme technologies, the lack of an enzyme reaction model accounting for the heterogeneous activity of single enzymes has hindered a quantitative understanding of the nonclassical stochastic outcome of single enzyme systems. Here we present a new statistical kinetics and exactly solvable models for clonal yet heterogeneous enzymes with possibly nonergodic state dynamics and state-dependent reactivity, which enable a quantitative understanding of modern single-enzyme experimental results for the mean and fluctuation in the number of product molecules created by single enzymes. We also propose a new experimental measure of the heterogeneity and nonergodicity for a system of enzymes.
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Affiliation(s)
- Seong Jun Park
- National Creative Research Initiative Center for Chemical Dynamics in Living Cells, Chung-Ang University , Seoul 06974, Korea
- National Institute of Innovative Functional Imaging, Chung-Ang University , Seoul 06974, Korea
| | - Sanggeun Song
- National Creative Research Initiative Center for Chemical Dynamics in Living Cells, Chung-Ang University , Seoul 06974, Korea
- Department of Chemistry, Chung-Ang University , Seoul 06974, Korea
- National Institute of Innovative Functional Imaging, Chung-Ang University , Seoul 06974, Korea
| | - In-Chun Jeong
- National Creative Research Initiative Center for Chemical Dynamics in Living Cells, Chung-Ang University , Seoul 06974, Korea
- Department of Chemistry, Chung-Ang University , Seoul 06974, Korea
- National Institute of Innovative Functional Imaging, Chung-Ang University , Seoul 06974, Korea
| | - Hye Ran Koh
- National Creative Research Initiative Center for Chemical Dynamics in Living Cells, Chung-Ang University , Seoul 06974, Korea
- Department of Chemistry, Chung-Ang University , Seoul 06974, Korea
| | - Ji-Hyun Kim
- National Creative Research Initiative Center for Chemical Dynamics in Living Cells, Chung-Ang University , Seoul 06974, Korea
| | - Jaeyoung Sung
- National Creative Research Initiative Center for Chemical Dynamics in Living Cells, Chung-Ang University , Seoul 06974, Korea
- Department of Chemistry, Chung-Ang University , Seoul 06974, Korea
- National Institute of Innovative Functional Imaging, Chung-Ang University , Seoul 06974, Korea
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Craig DB, King SD, Reinfelds G, Henderson AR, Wood TE. Electrophoretic mobility, catalytic rate, and activation energy of catalysis of single molecules of the enzyme β-glucuronidase from Escherichia coli. Int J Biol Macromol 2017; 96:669-674. [DOI: 10.1016/j.ijbiomac.2016.12.034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 10/12/2016] [Accepted: 12/12/2016] [Indexed: 12/28/2022]
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Crawford JJ, Itzkow F, MacLean J, Craig DB. Conformational change in individual enzyme molecules. Biochem Cell Biol 2015; 93:611-8. [PMID: 26529308 DOI: 10.1139/bcb-2015-0099] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Single β-galactosidase molecule assays were performed using a capillary electrophoresis based protocol, employing post-column laser-induced fluorescence detection. In a first set of experiments, the distribution of single β-galactosidase molecule catalytic rates and electrophoretic mobilities were determined from lysates of Escherichia coli strains containing deletions for different heat shock proteins and grown under normal and heat shock conditions. There was no clear observed pattern of effect of heat shock protein expression on these distributions. In a second set of experiments, individual enzyme molecule catalytic rates were determined at 21 °C before and after 2 sequential brief periods of incubation at 50, 28, and 10 °C. The brief incubations at 50 °C caused a change in the enzyme molecules resulting in a different catalytic rate. Any given molecule was just as likely to show an increase in rate as a decrease, resulting in no significant difference in the average rate of the population. The average change in individual molecule rate was dependent upon the temperature of the brief incubation period, with a lesser average change occurring at 28 °C and negligible change at 10 °C. A third set of experiments was similar to that of the second with the exception that it was electrophoretic mobility that was considered. This provided a similar result. Incubation at higher temperature resulted in a change in electrophoretic mobility. The probability of an individual molecules switching to a higher mobility was approximately equal to that of switching to a lower mobility, resulting in no net average change in the population. The magnitude of the changes in electrophoretic mobilities suggest that the associated conformational changes are subtle.
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Affiliation(s)
- Jeremie J Crawford
- a Department of Chemistry, 360 Parker Building, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Frannie Itzkow
- b Department of Chemistry, 599 Portage Avenue, University of Winnipeg, Winnipeg, MB R3B 2G3, Canada
| | - Joanna MacLean
- b Department of Chemistry, 599 Portage Avenue, University of Winnipeg, Winnipeg, MB R3B 2G3, Canada
| | - Douglas B Craig
- b Department of Chemistry, 599 Portage Avenue, University of Winnipeg, Winnipeg, MB R3B 2G3, Canada
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Enzyme molecules in solitary confinement. Molecules 2014; 19:14417-45. [PMID: 25221867 PMCID: PMC6271441 DOI: 10.3390/molecules190914417] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 09/03/2014] [Accepted: 09/03/2014] [Indexed: 11/17/2022] Open
Abstract
Large arrays of homogeneous microwells each defining a femtoliter volume are a versatile platform for monitoring the substrate turnover of many individual enzyme molecules in parallel. The high degree of parallelization enables the analysis of a statistically representative enzyme population. Enclosing individual enzyme molecules in microwells does not require any surface immobilization step and enables the kinetic investigation of enzymes free in solution. This review describes various microwell array formats and explores their applications for the detection and investigation of single enzyme molecules. The development of new fabrication techniques and sensitive detection methods drives the field of single molecule enzymology. Here, we introduce recent progress in single enzyme molecule analysis in microwell arrays and discuss the challenges and opportunities.
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Craig DB, Reinfelds G, Henderson A. 12-Channel Peltier array temperature control unit for single molecule enzymology studies using capillary electrophoresis. Electrophoresis 2014; 35:2408-11. [PMID: 24616017 DOI: 10.1002/elps.201300526] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 02/06/2014] [Accepted: 02/11/2014] [Indexed: 11/07/2022]
Abstract
Capillary electrophoresis has been used to demonstrate that individual molecules of a given enzyme support different catalytic rates. In order to determine how rate varies with temperature, and determine activation energies for individual β-galactosidase molecules, a 12-channel Peltier array temperature control device was constructed where the temperature of each cell was separately controlled. This array was used to control the temperature of the central 30 cm of a 50 cm long capillary, producing a temperature gradient along its length. Continuous flow single β-galactosidase molecule assays were performed allowing measurement of the catalytic rates at different temperatures. Arrhenius plots were produced and the distribution of activation energies for individual β-galactosidase molecules was found to be 56 ± 10 kJ/mol with a range of 34-72 kJ/mol.
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Affiliation(s)
- Douglas B Craig
- Chemistry Department, University of Winnipeg, Winnipeg, MB, Canada
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Rojek MJ, Walt DR. Observing single enzyme molecules interconvert between activity states upon heating. PLoS One 2014; 9:e86224. [PMID: 24465972 PMCID: PMC3897666 DOI: 10.1371/journal.pone.0086224] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Accepted: 12/09/2013] [Indexed: 11/18/2022] Open
Abstract
In this paper, we demonstrate that single enzyme molecules of β-galactosidase interconvert between different activity states upon exposure to short pulses of heat. We show that these changes in activity are the result of different enzyme conformations. Hundreds of single β-galactosidase molecules are trapped in femtoliter reaction chambers and the individual enzymes are subjected to short heating pulses. When heating pulses are introduced into the system, the enzyme molecules switch between different activity states. Furthermore, we observe that the changes in activity are random and do not correlate with the enzyme's original activity. This study demonstrates that different stable conformations play an important role in the static heterogeneity reported previously, resulting in distinct long-lived activity states of enzyme molecules in a population.
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Affiliation(s)
- Marcin J. Rojek
- Department of Chemistry, Tufts University, Medford, Massachusetts, United States of America
| | - David R. Walt
- Department of Chemistry, Tufts University, Medford, Massachusetts, United States of America
- * E-mail:
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Craig DB, Bayaraa B, Lee D, Charleton J. EFFECT OF INDUCTION TEMPERATURE AND PARTIAL THERMAL DENATURATION ON THE CATALYTIC AND ELECTROPHORETIC HETEROGENEITY OF β-GALACTOSIDASE FROM TWO ESCHERICHIA COLI STRAINS. J LIQ CHROMATOGR R T 2013. [DOI: 10.1080/10826076.2012.731672] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Douglas B Craig
- a Chemistry Department , University of Winnipeg , Winnipeg , Manitoba , Canada
| | - Bayasgalan Bayaraa
- a Chemistry Department , University of Winnipeg , Winnipeg , Manitoba , Canada
| | - Dorice Lee
- a Chemistry Department , University of Winnipeg , Winnipeg , Manitoba , Canada
| | - Justin Charleton
- a Chemistry Department , University of Winnipeg , Winnipeg , Manitoba , Canada
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Electrophoretic heterogeneity limits the utility of streptavidin-β-galactosidase as a probe in free zone capillary electrophoresis separations. Protein J 2013; 32:81-8. [PMID: 23325029 DOI: 10.1007/s10930-013-9464-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Single molecule assays were performed on streptavidin-β-galactosidase using a capillary electrophoresis-based protocol in order to assess the suitability of single molecule β-galactosidase assays for adaptation to the detection of single copies of target DNA. The conjugate was found to have a heterogeneous catalytic rate, showing an average rate of 44,000 ± 24,000 min(-1), which is similar to that of the unmodified enzyme. Electrophoretic mobility was also measured on individual molecules and determined to be -1.32 × 10(-4) ± 0.19 × 10(-4) cm(2)V(-1)s(-1). The variance in mobility was several times that reported for the unmodified enzyme. The electrophoretic heterogeneity was found to result in the formation of a broad window of peaks in the resultant electropherograms of free zone separations of small plugs of streptavidin-β-galactosidase. This range of mobilities largely overlapped with that of the conjugate bound to primer and plasmid containing a target DNA sequence. This overlap suggests that the separation of free conjugate from that bound to target DNA, which is a requirement for application of the single enzyme molecule assay to the detection of target DNA sequences, is not plausible using free zone capillary electrophoresis.
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