Proteomics and Mass Spectrometry Core Facility is putting tobacco settlement funds to innovative good use
By: Seth Palmer
Since purchasing the LTQ Orbitrap in June 2011 with funds that resulted from the Tobacco Master Settlement Agreement, the Proteomics and Mass Spectrometry Core Facility has been continually building its expertise in integrating mass spectrometry-based proteomics into systems biology workflows.
As a result, a growing number of scientists at Penn State and beyond are turning to the Facility to advance their research with biological MS analysis, and relying on the Orbitrap for its high resolving power, detection sensitivity, and variety of fragmentation modes, as well as its powerful data-processing platform.
Mechanisms of enzyme catalysis
Squire Booker’s lab is studying mechanisms of enzyme catalysis — particularly the use of co-factors (metal ions and their clusters and small molecules) to expand enzymes' catalytic capabilities beyond the 20 naturally occurring amino acids — potentially yielding insights that could promote the design of new drugs, such as antibiotics to combat resistant microorganisms.
Analyses performed with the Orbitrap identified a site of disulfide linkage in one of the proteins under study — revealing a key point for targeted investigation.
Cfr and RlmN Contain a Single [4Fe-4S] Cluster, which Directs Two Distinct Reactivities for S-Adenosylmethionine: Methyl Transfer by SN2 Displacement and Radical Generation. Tyler L. Grove, Matthew I. Radle, Carsten Krebs, and Squire J. Booker. Journal of the American Chemical Society 2011; 133(49): 19586-19589.
Modifications of enzymes and proteins
Martin Bollinger and Carsten Krebs have also used the Orbitrap in identifying modifications on intact enzymes — for instance, where an unexpected glycosylation of N-termini was identified, characterizing an unusual intramolecular Tyrosine-Valine linkage — and in other applications, such as identifying d2Tyr modifications of expressed proteins.
Drug-peptide conjugates related to antibiotic resistance
Ken Keiler’s lab found the Orbitrap's high dynamic range of sensitivity to be critical in their identification of a drug-peptide conjugate present in a less-than-0.1% amount of unmodified protein; the ability to pinpoint this drug binding/cross-linking site facilitated more targeted studies in the lab — saving the researchers significant time and money.
Protein expression in organisms
The Orbitrap’s HCD/CID fragmentation capability has been extensively exploited by researchers interested in differential protein expression in organisms exposed to various internal and external stimuli. Dawn Luthe, Siela Maximova, Mark Guiltinan, and Gary Felton have used tandem mass tags (TMT) stable isotope labeling to analyze samples ranging from plant tissues to caterpillar frass and saliva, and David Hughes is using the Orbitrap to identify fungus-secreted proteins that may control or modify insect behavior, such as in the case of zombie ants.
Anthropology professor Douglas Kennett used the Orbitrap to analyze collagen from a 1,000 year-old bone, part of a sea otter skeleton excavated from the Channel Islands in California. Archaeologists had already identified the bone's origin, but wondered if collagen extracted from the bone (and, by extension, from other bones of similar age) would be usable for analysis; the Orbitrap matched the collagen to a library of proteins from the suborder Caniformia, of which otters are a member.
And proteomic analyses using the Orbitrap are also at the core of the Facility's collaboration with Jenora Waterman, a researcher at North Carolina A&T University who is using animal models to study human respiratory disease caused by environmental agents.
A broad user base
There are currently more than 30 faculty at University Park who regularly use the Orbitrap, nearly a dozen from the College of Medicine and from outside the University, and the user base is constantly growing.
In addition to providing analytical services, the Facility also hosts hands-on workshops and trainings, and provides letters of support for a number of Penn State faculty — including at the Hershey Medical Center — as well as for external faculty whose research is aimed at a broad spectrum of problems ranging from human disease and drug resistance to ecosystems and renewable energy.
Interested? Curious? Intrigued?
If you're wondering about the possibilities that the Thermo LTQ Orbitrap Velos and biological MS analysis can bring to your research, contact Tania Laremore, Director of the Proteomics and Mass Spectrometry Core Facility.