Enhanced Single Molecule Mass Spectrometry via Charged Metallic Clusters

Angevine, Christopher E.; Chavis, Amy E.; Kothalawala, Nuwan; Dass, Amala; Reiner, Joseph E.

doi:10.1021/ac503425g

Cited by 28 publications

(55 citation statements)

References 50 publications

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“…In addition, having control over the single-molecule trap allows the interrogation of a single polypeptide interacting with the α-HL pore at tunable residence times, and possibly provide a wealth of information about the primary sequence and interaction with the pore. In another recent work, it was shown that the Coulombic interaction between a charged analyte and a metallic cluster bound to α-HL plays an important role in the residence time enhancement 57 .…”

Section: Discussionmentioning

confidence: 99%

Placement of oppositely charged aminoacids at a polypeptide termini determines the voltage-controlled braking of polymer transport through nanometer-scale pores

Asandei

Chinappi

Lee

et al. 2015

Sci Rep

117

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Protein and solid-state nanometer-scale pores are being developed for the detection, analysis, and manipulation of single molecules. In the simplest embodiment, the entry of a molecule into a nanopore causes a reduction in the latter’s ionic conductance. The ionic current blockade depth and residence time have been shown to provide detailed information on the size, adsorbed charge, and other properties of molecules. Here we describe the use of the nanopore formed by Staphylococcus aureus α-hemolysin and polypeptides with oppositely charged segments at the N- and C-termini to increase both the polypeptide capture rate and mean residence time of them in the pore, regardless of the polarity of the applied electrostatic potential. The technique provides the means to improve the signal to noise of single molecule nanopore-based measurements.

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Section: Discussionmentioning

confidence: 99%

Placement of oppositely charged aminoacids at a polypeptide termini determines the voltage-controlled braking of polymer transport through nanometer-scale pores

Asandei

Chinappi

Lee

et al. 2015

Sci Rep

117

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show abstract

“…It seems evident that the single-monomer resolution of size-discrimination observed with the PEG/ α -hemolysin system, and recently also with PEG/metallic-clusters/ α -hemolysin1521, with PEG/aerolysin20 and with short oligonucleotides/aerolysin22, can only occur if each monomer contributes to the current blockade, i.e. when the polymer is fully accommodated in the pore.…”

mentioning

confidence: 95%

High Temperature Extends the Range of Size Discrimination of Nonionic Polymers by a Biological Nanopore

Piguet¹,

Ouldali²,

Discala³

et al. 2016

Sci Rep

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We explore the effect of temperature on the interaction of polydisperse mixtures of nonionic poly(ethylene glycol) (PEG) polymers of different average molar masses with the biological nanopore α-hemolysin. In contrast with what has been previously observed with various nanopores and analytes, we find that, for PEGs larger than a threshold molar mass (2000 g/mol, PEG 2000), increasing temperature increases the duration of the PEG/nanopore interaction. In the case of PEG 3400 the duration increases by up to a factor of 100 when the temperature increases from 5 °C to 45 °C. Importantly, we find that increasing temperature extends the polymer size range of application of nanopore-based single-molecule mass spectrometry (Np-SMMS)-type size discrimination. Indeed, in the case of PEG 3400, discrimination of individual molecular species of different monomer number is impossible at room temperature but is achieved when the temperature is raised to 45 °C. We interpret our observations as the consequence of a decrease of PEG solubility and a collapse of PEG molecules with higher temperatures. In addition to expanding the range of application of Np-SMMS to larger nonionic polymers, our findings highlight the crucial role of the polymer solubility for the nanopore detection.

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“…24,25 The method is conceptually simple. An electric potential applied across a nanopore that spans two electrically isolated chambers (filled with electrolyte solutions) results in an ionic current with a mean value 〈 i 0 〉 (Figure 1B).…”

mentioning

confidence: 99%

MOSAIC: A Modular Single-Molecule Analysis Interface for Decoding Multistate Nanopore Data

et al. 2016

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Biological and solid-state nanometer-scale pores are the basis for numerous emerging analytical technologies for use in precision medicine. We developed Modular Single-Molecule Analysis Interface (MOSAIC), an open source analysis software that improves the accuracy and throughput of nanopore-based measurements. Two key algorithms are implemented: ADEPT, which uses a physical model of the nanopore system to characterize short-lived events that do not reach their steady-state current, and CUSUM+, a version of the cumulative sum statistical method optimized for longer events that do. We show that ADEPT detects previously unreported conductance states that occur as double-stranded DNA translocates through a 2.4 nm solid-state nanopore and reveals new interactions between short single-stranded DNA and the vestibule of a biological pore. These findings demonstrate the utility of MOSAIC and the ADEPT algorithm, and offer a new tool that can improve the analysis of nanopore-based measurements.

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Enhanced Single Molecule Mass Spectrometry via Charged Metallic Clusters

Cited by 28 publications

References 50 publications

Placement of oppositely charged aminoacids at a polypeptide termini determines the voltage-controlled braking of polymer transport through nanometer-scale pores

Placement of oppositely charged aminoacids at a polypeptide termini determines the voltage-controlled braking of polymer transport through nanometer-scale pores

High Temperature Extends the Range of Size Discrimination of Nonionic Polymers by a Biological Nanopore

MOSAIC: A Modular Single-Molecule Analysis Interface for Decoding Multistate Nanopore Data

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