ICR Science Highlights
Decoding the human proteome with powerful mass spectrometer
The MagLab’s 21-tesla FT-ICR magnet can identify human proteins far more efficiently than commercial instruments, a boon for medical research.
MagLab develops, shares chemical analysis software
The high-tech tools empower scientists studying petroleum and other molecules to make decisions based on advanced data analysis.
A new twist on DNA
Research sheds important light on the fundamental process of cell division.
Removing "water-loving" molecules from petroleum
Scientists have developed a way to isolate emulsion-causing petroleum compounds. The technique may help lower energy costs for both oil companies and consumers.
Protein modifications in human breast cancer
We have discovered biomarkers that make it possible to distinguish breast cancer cells from non-cancerous cells, based on identifying chemical modifications of histones, the molecules about which DNA strands are wound to keep them in the cell nucleus. The method uses a high-field magnet to spread out the signals from different parts of the histone, to locate the site(s) of chemical modifications.
FT-ICR Mass Spectrometry Enables Peptide de novo Sequencing
We describe a method for de novo protein sequencing with high accuracy and multiple levels of confidence. Samples are digested separately by two proteases, Lys-C and Lys-N. The resulting complementary pairs of ions combine to improve confidence in the identification.
Endohedral Metallofullerenes are Formed by Directed by Charge Transfer
An understanding of the formation mechanism of endohedral metallofullerenes may pave the way towards targeted synthesis of these nanomaterials, which are attractive for use in biomedicine and renewable energy. Their bottom-up synthesis is investigated and charge transfer from the encapsulated metal to carbon cage is determined to play a key role in formation.
Targeted Petroleomics: Macondo Well Oil Oxidation Products on Pensacola Beach
The explosion of the Deepwater Horizon oil rig in April 2012 resulted in the release of ~5 million barrels of crude oil into the Gulf of Mexico ecosystem, a fraction of which washed ashore onto Gulf beaches. We compare the detailed molecular analysis of hydrocarbons in oiled sands from Pensacola Beach to the Macondo wellhead oil (MWO) by Fourier transform ion cyclotron resonance mass spectrometry to identify major environmental transformation products of polar, high molecular weight petrogenic material from Pensacola Beach.
Direct Characterization of Porphyrins in Petroleum from Natural Seeps
Atmospheric pressure photoionization (APPI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) provides ultrahigh resolving power (m/Δm50% > 1,000,000 at m/z 500) and sub-ppm mass error (50 ppb) required to identify nickel porphyrin isotopes for unambiguous elemental composition assignment. We also report the first simultaneous identification and categorization of both vanadyl and nickel porphyrins in the same sample, without prior sample fractionation.
Nucleotide-Induced Conformational Changes in Tetrameric GroEL Mapped by Hydrogen/Deuterium Exchange
GroEL is a large (molecular weight ≈ 800,000) protein complex composed of two heptamers arranged like stacked doughnuts. By “spray-painting” the complex with heavy water, and then cutting into pieces with an enzyme and weighing the pieces, we are able to map the solvent accessibility throughout the complex, and observe conformational changes induced by binding of an analog of adenosine triphosphate (ATP), thereby illuminating the mechanism by which ATP activates the complex for its biological function.
Oil Spill Characterization by Ultrahigh Resolution ICR Mass Spectrometry
Traditional tools for routine environmental analysis and forensic chemistry of petroleum have relied almost exclusively on gas chromatography-mass spectrometry (GC-MS), although many compounds in crude oil (and its transformation products) are not chromatographically separated or amenable to GC-MS due to volatility. We apply ultrahigh resolution Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry to identify compositional changes at the molecular level between native and weathered crude oil samples and reveal enrichment in polar compounds inaccessible by GC-based characterization.
Creating a Pseudo-Atomic Model of the COPII Cage
Using a novel combination of techniques, scientists researching the COPII protein created a pseudo-atomic model of the COPII cage, gaining a better understanding of how its 96 subunits fit together.
Characterization of Pine Pellet and Peanut Hull Pyrolysis Bio-Oils by Negative-Ion Electrospray Ionization FT&-ICR Mass Spectrometry
Pyrolysis of solid biomass, in this case pine pellets and peanut hulls, generates a hydrocarbon-rich liquid product (bio-oil) consisting of oily and aqueous phases. Here, each phase is characterized by negative-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) to yield unique chemical formulas for thousands of compounds.
Powerful New Ionization Technique for Mass Spectroscopy That Avoids Fragmentation of Saturated Hydrocarbons
Here, we present a powerful new approach for the analysis of saturated hydrocarbon mixtures: atmospheric pressure laser- induced acoustic desorption chemical ionization (AP/LIAD-CI) with oxygen carrier/reagent gas.
The Smallest Stable Fullerene, M@C28 (M = Ti, Zr, U)
Buckminster Fullerenes ("Buckyballs") have fascinated chemists since the original discovery of C60, leading to the 1996 Nobel Prize in Chemistry for Curl, Kroto and Smalley. Although fullerenes of various sizes have since been observed, the theoretically smallest fullerene, C28, has until now escaped detection, due to its high curvature and thus high reactivity.