Attomole Protein Characterization by Capillary Electrophoresis-Mass Spectrometry

Valaskovic, Gary A.; Kelleher, Neil L.; McLafferty, Fred W.

doi:10.1126/science.273.5279.1199

Cited by 385 publications

(315 citation statements)

References 32 publications

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“…10,11 At nanoliter per min flow rates, the attomole limit of detection of proteins is possible. 12 With these successes, the edge of envelope was further pushed by Wilm and Mann 13,14 who introduced nano-electrospray (or nanospray) ionization with further decreased flow rate. Without the use of solvent pump, this static nanospray ion source allows the liquid to flow through the spray emitter by capillary action when high voltage is applied.…”

Section: Introductionmentioning

confidence: 99%

Characterizing Electrospray Ionization Using Atmospheric Pressure Ion Mobility Spectrometry

2006

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Reduced flow-rate electrospray ionization has been proven to provide improved sensitivity, less background noise, and improved limits of detections for ESI-MS analysis. Miniaturizing the ESI source from conventional electrospray to micro-electrospray and further down to nanoelectrospray has resulted in higher and higher sensitivity. However, when effects of flow rate were investigated for atmospheric pressure ESI-IMS using a nanospray emitter, a striking opposite result was observed. The general tendency we observed in ESI-IMS was that higher flow rate offered higher ion signal intensity throughout a variety of conditions investigated. Thus further efforts were undertaken to rationalize these contradictory results. It is well accepted that decreased flow rate increases both ionization efficiency and transmission efficiency thus improves ion signal in ESI-MS. However, our study revealed that decreased flow rate results in decreased ion signal because ion transfer is constant no matter how flow rate changes in ESI-IMS. Since ion transfer is constant in atmospheric pressure ESI-IMS, ionization efficiency can be studied independently, which otherwise is not possible in ESI-MS where both ionization efficiency and transmission efficiency vary as conditions alter. In this report, we present a systematic study on signal intensity and ionization efficiency at various experimental conditions using ESI-IMS and demonstrated the ionization efficiency as a function of flow rate, analyte concentration, and solvent composition.

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Section: Introductionmentioning

confidence: 99%

Characterizing Electrospray Ionization Using Atmospheric Pressure Ion Mobility Spectrometry

2006

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“…The translational energy (E tr ) of the excited ions in the SORI experiment is given by E tr = (ε / 2) 2 e 2 2m(Δω) 2 sin 2 ( Δωt 2 ) (2) where e is the ion charge, t is the duration of the excitation wave form, and m is the mass of the ion. 22…”

Section: Introductionmentioning

confidence: 99%

The Effective Temperature of Peptide Ions Dissociated by Sustained Off-Resonance Irradiation Collisional Activation in Fourier Transform Mass Spectrometry

1999

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A method for determining the internal energy of biomolecule ions activated by collisions is demonstrated. The dissociation kinetics of protonated leucine enkephalin and doubly protonated bradykinin were measured using sustained off-resonance irradiation (SORI) collisionally activated dissociation (CAD) in a Fourier transform mass spectrometer. Dissociation rate constants are obtained from these kinetic data. In combination with Arrhenius parameters measured with blackbody infrared radiative dissociation, the "effective" temperatures of these ions are obtained. Effects of excitation voltage and frequency and the ion cell pressure were investigated. With typical SORI-CAD experimental conditions, the effective temperatures of these peptide ions range between 200 and 400 °C. Higher temperatures can be easily obtained for ions that require more internal energy to dissociate. The effective temperatures of both protonated leucine enkephalin and doubly protonated bradykinin measured with the same experimental conditions are similar. Effective temperatures for protonated leucine enkephalin can also be obtained from the branching ratio of the b 4 and (M + H − H 2 O) + pathways. Values obtained from this method are in good agreement with those obtained from the overall dissociation rate constants. Protonated leucine enkephalin is an excellent "thermometer" ion and should be well suited to establishing effective temperatures of ions activated by other dissociation techniques, such as infrared photodissociation, as well as ionization methods, such as matrix assisted laser desorption/ionization.

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“…While FTICR-MS has a demonstrated capability for ultra-sensitive characterization of biopolymers (e.g., achieving subattomole detection limits) (Belov, et al, 2000a, Valaskovic, et al, 1996, the maximum dynamic range for a single mass spectrum (without the use of spectrum averaging or summation) is typically constrained to about 10 3 . An important factor that has conventionally limited achievable FTICR-MS sensitivity and dynamic range is the maximum charge capacity of either the external ion accumulation device or the FTICR mass analyzer itself.…”

Section: Dynamic Range Enhancement Applied To Mass Spectrometry (Dreams)mentioning

confidence: 99%

Advances in proteomics data analysis and display using an accurate mass and time tag approach

Zimmer

Monroe

Qian

et al. 2006

Mass Spectrometry Reviews

293

360

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Proteomics has recently demonstrated utility in understanding cellular processes on the molecular level as a component of systems biology approaches and for identifying potential biomarkers of various disease states. The large amount of data generated by utilizing high efficiency (e.g., chromatographic) separations coupled to high mass accuracy mass spectrometry for high-throughput proteomics analyses presents challenges related to data processing, analysis, and display. This review focuses on recent advances in nanoLC-FTICR-MS-based proteomics approaches and the accompanying data processing tools that have been developed to display and interpret the large volumes of data being produced.

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Attomole Protein Characterization by Capillary Electrophoresis-Mass Spectrometry

Abstract: Electrospray ionization with an ultralow flow rate (30 kilodaltons) at a resolving power of approximately 60,000 for injections of 0.7 x 10(-18) to 3 x 10(-18) mole of 8- to 29-kilodalton proteins with errors of <1 dalton in molecular mass. Using a crude isolate from human bl… Show more

Cited by 385 publications

References 32 publications

Characterizing Electrospray Ionization Using Atmospheric Pressure Ion Mobility Spectrometry

Characterizing Electrospray Ionization Using Atmospheric Pressure Ion Mobility Spectrometry

The Effective Temperature of Peptide Ions Dissociated by Sustained Off-Resonance Irradiation Collisional Activation in Fourier Transform Mass Spectrometry

Advances in proteomics data analysis and display using an accurate mass and time tag approach

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