Office of Science

2002 M. T. Thomas Award

Laskin Recognized for Outstanding Postdoctoral Achievement

Dr. Julia Laskin has been selected as the 2002 recipient of the M. T. Thomas Award for Outstanding Postdoctoral Achievement.

She was selected for her pivotal experimental and theoretical contributions to the fundamental understanding of collision and surface-induced activation and fragmentation of large molecules and peptides.

The structurally specific fragmentation of protonated peptides is the fundamental basis of applications of mass spectrometry in proteomics—an enormously important research field driving national biochemistry initiatives. Dr. Laskin's work on collisional and surface induced activation of complex molecules—particularly biomolecules—using Fourier transform ion cyclotron resonance mass spectrometry methods (Laskin et al. 2000) has enabled researchers to address the fundamental kinetics and dynamics of activating and dissociating protonated peptides.

Dr. Laskin not only contributed to the design and construction of a major research apparatus—the only one of its kind in the world—but also developed and implemented a theoretical model of activation and dissociation to analyze the experimental data obtained. The model she developed and tested has provided, for the first time, a firm theoretical and experimental foundation for understanding surface-induced dissociation (SID), and made it possible to measure critical dissociation energies of large molecules with higher precision than other known methods. During the course of her studies Dr. Laskin obtained highly quantitative data and applied comprehensive analysis to interpret peptide dissociation kinetics in terms of activation entropies and enthalpies, thereby specifying the characteristics of transition states for this important class of reactions. Dr. Laskin also discovered that for large peptides at high impact energies a "shattering transition" occurs in which dissociation occurs during surface impact or immediately thereafter (Laskin and Futrell 2003). These paradigm-shifting discoveries significantly modify our understanding of large molecule SID.

In tandem mass spectrometry investigations Dr. Laskin demonstrated that careful measurement of kinetic energy distributions of product ions and branching ratios for competitive dissociation of proton-bound dimers—when analyzed using a new theoretical model she developed—enables the determination of both fragmentation energetics and entropies. The strong correlation she discovered between Arrhenius A factors and activation energies for the dissociation of proteins and protein complexes has provided the key insight that entropy rather than energetic factors is the principal driving force for these reactions (Laskin and Futrell 2000). These broad insights extend far beyond SID into the interpretation of thermal, photon, and multiple collision induced dissociation of complex ions.

Laskin J, E Denisov, and J Futrell. 2000. "A Comparative Study of Collision-Induced and Surface-Induced Dissociation. 1. Fragmentation of Protonated Dialanine." J. Am. Chem. Soc. 122, 9703-9714.

Laskin J and J Futrell. 2003. "Shattering of Peptide Ions on Self-Assembled Monolayer Surfaces." J. Am. Chem. Soc. 125, 1625-1632.

Laskin J and J Futrell. 2000. "The theoretical Basis of the Kinetic Method from the Point of View of Finite Heat Bath Theory." J. Phys. Chem. A. 104, 8829-8837.