UC Riverside

The development of mass spectrometry (MS) as a tool for the characterization of biological molecules has seen rapid growth over the past three decades. The structure of a peptide or protein is key to its function and the role it plays within a biological environment. Several tools are available for determination of primary structure, however higher order structural characterization continues to be more challenging. As such, the development of new analytical methodology for the structural characterization of peptides and proteins is of significant interest.

Wavelength selection is key to modulate fragmentation and biomolecule characterization when combining spectroscopy and MS. By coupling 213nm ultraviolet photodissociation (UVPD) with MS, both bond-specific dissociation and traditional nonspecific UVPD are observed. 213nm UVPD showed enhanced Carbon-Sulfur bond dissociation, leading to an investigation of their potential as energy acceptors in an action excitation energy transfer system. 266nm excitation of synthetic peptides containing methionine and a native aromatic donor revealed low energy transfer efficiency, leading to an investigation of a common methionine analogue: selenomethionine. Examination of C-Se bonds within synthetic peptides revealed enhanced energy transfer efficiency. This indicates selenomethionine may prove useful for probing protein structure in the gas phase. Photoinitiated radical chemistry has proven useful for breaking covalent bonds but may also have a role in a different application: bond synthesis in the gas phase. To show this, 266nm photoactivation of peptides, peptide pairs, and peptide-noncovalent complexes that contained either S-S or C-I bonds create sulfur- and carbon-centered radicals. Following radical attack or radical migration, the formation of new S-S or C-C bonds in the gas phase.

The development and implementation of education tools, to improve student learning gains, is a key area of research in chemical education. A quarter-long concept mapping exercise was used in an effort to improve student conceptual understanding. Students participating in the quasi-experiment showed higher self-reported learning gains, and those that performed better on the concept mapping activity scored higher on concept inventory questions. Collectively, this work demonstrates that chemistry in the laboratory is just as important as chemistry in the classroom, and advances in both will lead to better scientific innovation.