Streptococcus gordonii soluble inorganic pyrophosphatase: An important role for the interdomain region in enzyme activity

Ilias, Mohammad; Young, Tom

doi:10.1016/j.bbapap.2006.05.007

Cited by 22 publications

(14 citation statements)

References 26 publications

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“…2 E ; see free dye group), similar in magnitude to those seen in experiments with ALP-JF646. Second, we measured the diffusion coefficient of Atto647N-labeled Streptococcus gordonii ( sg ) inorganic pyrophosphatase ( 25 ) ( sg PP-Atto647N) (see SI Appendix , Materials and Methods for details) before and after addition of 2 mM p NPP. Even though p NPP is not a substrate of sg PP, we again observed a 17% apparent D enhancement and increase in the dispersion of D ( Fig.…”

Section: Resultsmentioning

confidence: 99%

Single-molecule diffusometry reveals no catalysis-induced diffusion enhancement of alkaline phosphatase as proposed by FCS experiments

Chen

Shaw

Wilson

et al. 2020

Proc. Natl. Acad. Sci. U.S.A.

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Theoretical and experimental observations that catalysis enhances the diffusion of enzymes have generated exciting implications about nanoscale energy flow, molecular chemotaxis, and self-powered nanomachines. However, contradictory claims on the origin, magnitude, and consequence of this phenomenon continue to arise. To date, experimental observations of catalysis-enhanced enzyme diffusion have relied almost exclusively on fluorescence correlation spectroscopy (FCS), a technique that provides only indirect, ensemble-averaged measurements of diffusion behavior. Here, using an anti-Brownian electrokinetic (ABEL) trap and in-solution single-particle tracking, we show that catalysis does not increase the diffusion of alkaline phosphatase (ALP) at the single-molecule level, in sharp contrast to the ∼20% enhancement seen in parallel FCS experiments using p-nitrophenyl phosphate (pNPP) as substrate. Combining comprehensive FCS controls, ABEL trap, surface-based single-molecule fluorescence, and Monte Carlo simulations, we establish that pNPP-induced dye blinking at the ∼10-ms timescale is responsible for the apparent diffusion enhancement seen in FCS. Our observations urge a crucial revisit of various experimental findings and theoretical models––including those of our own––in the field, and indicate that in-solution single-particle tracking and ABEL trap are more reliable means to investigate diffusion phenomena at the nanoscale.

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Section: Resultsmentioning

confidence: 99%

Single-molecule diffusometry reveals no catalysis-induced diffusion enhancement of alkaline phosphatase as proposed by FCS experiments

Chen

Shaw

Wilson

et al. 2020

Proc. Natl. Acad. Sci. U.S.A.

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“…B), the active site is formed at the domain interface, allowing substrate analog binding. Domain closure and opening appear to be essential for catalytic function . The Family II PPase from Streptococcus aureus adopts the closed conformation in the absence of substrate, which causes a further induced‐fit conformational change in the loop containing a conserved Arg‐Lys‐Lys motif .…”

Section: Structurementioning

confidence: 99%

Inorganic pyrophosphatases of Family II—two decades after their discovery

et al. 2017

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Edited by Miguel De la RosaInorganic pyrophosphatases (PPases) convert pyrophosphate (PP i ) to phosphate and are present in all cell types. Soluble PPases belong to three nonhomologous families, of which Family II is found in approximately a quarter of prokaryotic organisms, often pathogenic ones. Each subunit of dimeric canonical Family II PPases is formed by two domains connected by a flexible linker, with the active site located between the domains. These enzymes require both magnesium and a transition metal ion (manganese or cobalt) for maximal activity and are the most active (k cat % 10 4 s À1 ) among all PPase types. Catalysis by Family II PPases requires four metal ions per substrate molecule, three of which form a unique trimetal center that coordinates the nucleophilic water and converts it to a reactive hydroxide ion. A quarter of Family II PPases contain an autoinhibitory regulatory insert formed by two cystathionine b-synthase (CBS) domains and one DRTGG domain. Adenine nucleotide binding either activates or inhibits the CBS domain-containing PPases, thereby tuning their activity and, hence, PP i levels, in response to changes in cell energy status (ATP/ADP ratio).

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“…Under cellular conditions, ATP could be metabolized into a pyrophosphate ion (PPi) and thus the level of PPi could partially be used as an indicator of ATP consumption. Moreover, PPi could, to some extent, be regarded as an energy source and perform functions in central nervous systems . Some reports suggested that the ratio of PPi/Pi, rather than the ratio of ATP/ADP, plays the most important role in the carbohydrate metabolism, providing energy for many biosynthetic reactions and working as a thermodynamic pull .…”

Section: Colorimetric Sensingmentioning

confidence: 99%

Visualization and Quantification of Neurochemicals with Gold Nanoparticles: Opportunities and Challenges

Deng

Wang

et al. 2014

Advanced Materials

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Gold nanoparticle (Au-NP)-based colorimetric assays offer new opportunitites for the visualization and quantification of neurochemicals involved in physiological and pathological processes due to their high sensitivity, designability, and low technical demands. In this Research News, we systematically review the advances on the development of Au-NP-based colorimetric methods for visualization and quantification of neurochemicals and their potential applications for effectively monitoring neurochemicals in the central nervous system. By integration of the favourable surface chemistry with the high extinction coefficient of Au-NPs, some new principles and methods could be developed for the quantification of neurochemicals involved in brain functions. New strategies to design the surface chemistry of Au-NPs, along with the key challenges yet to be addressed to achieve online visualization and quantification of neurochemicals in the central nervous system, are illustrated and discussed. The questions opened here should inspire future investigations and lead to discoveries that continue the development of the effective analytical protocols based on Au-NPs for neurochemical visualization and quantification.

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Streptococcus gordonii soluble inorganic pyrophosphatase: An important role for the interdomain region in enzyme activity

Cited by 22 publications

References 26 publications

Single-molecule diffusometry reveals no catalysis-induced diffusion enhancement of alkaline phosphatase as proposed by FCS experiments

Single-molecule diffusometry reveals no catalysis-induced diffusion enhancement of alkaline phosphatase as proposed by FCS experiments

Inorganic pyrophosphatases of Family II—two decades after their discovery

Visualization and Quantification of Neurochemicals with Gold Nanoparticles: Opportunities and Challenges

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