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.
McKenna specializes in examining petroleum that is particularly difficult to refine. She’ll discuss the nature of oil and the 2010 BP spill in the Gulf of Mexico.
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.
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.
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.
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.
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.
Chemist Amy McKenna describes her path to science and to the MagLab
Meet one of the greatest innovators in the history of mass spectrometry, hard at work.