Stephen F. Macha, Ph.D. (Co-Director, Mass Spectrometry Facility)

Stephen Macha (

A graduate of Louisiana State University, Stephen studied the characterization of synthetic polymers utilizing Matrix-Assisted Laser Desoption Ionization (MALDI) mass spectrometry under the direction of Patrick A. Limbach. Stephen continued his collaboration with Pat as a post-doc in the field of proteomics before joining the University of Cincinnati's Mass Spectrometry Facility. He has been a member of the American Society for Mass Spectrometry for 21 years.

With over 26 years in mass spectrometry, Stephen has acquired a broad expertise in many mass spectrometric techniques. His areas of expertise include, but are not limited to, characterization of low molecular weight organic and inorganic synthesis products, MALDI-MS analysis of technical and biological polymers, and GC-MS. Collaborations include other departments in the College of Arts & Sciences (including Biological Sciences and Geology), and working with investigators in the College of Engineering and Applied Science. Stephen has 12 peer-reviewed publications.

Larry Sallans, Ph.D. (Co-Director, Mass Spectrometry Facility)

Larry Sallans (

A graduate of Purdue University, Larry studied ion-molecule chemistry utilizing Fourier transform ion cyclotron resonance mass spectrometry under the direction of Ben S. Freiser. While at Purdue he also extensively collaborated with Robert R. Squires using Flowing Afterglow techniques and attended studies in mass spectrometry with R. Graham Cooks. He has been a member of the American Society for Mass Spectrometry for approximately 35 years.

With over 38 years of bench-level experience exclusively in the area of mass spectrometry, Larry's focus has been non-routine analysis involving identification of unknowns and quantitation including over 19 years industrial experience ranging from solving process and product problems to identifying and characterizing competitor products. His academic collaborations have also led to a very broad range of experience dealing with projects from chemistry, biology, pharmacy, and medicine from various University of Cincinnati departments and schools, other universities, and industry. Larry has 36 peer-reviewed publications.

Selected peer-reviewed publications (in reverse-chronological order).

Taylor, R.M.; Sallans, L.; Frankel, L.K.; Bricker, T.M.; “Natively Oxidized Amino Acid Residues in the Spinach Cytochrome b6f Complex” Photosynthesis Research, 2018, 137, 141-151

Kale, R.; Hebert, A.E.; Frankel, L.K.; Sallans, L.; Bricker, T.M.; Pospíšila, P.; “Amino acid oxidation of the D1 and D2 proteins by oxygen radicals during photoinhibition of Photosystem II” Proc. Natl. Acad. Sci.,  2017, 114, 2988-2993

Mummadisetti, M.; Frankel, L.; Bellamy, H.; Sallans, L.; Goettert, J.; Brylinski, M.; Bricker, T. “Use of Protein Crosslinking and Radiolytic Labeling to Elucidate the Structure of PsbO within Higher Plant Photosystem II” Biochemistry, 2016, 55, 3204-3213

Mor, V.; Rella, A.; Farnoud, A.M.; Singh, A.; Munshi, M.; Bryan, A.; Naseem, S.; Konopka, J.B.; Ojima, I.; Bullesbach, E.; Ashbaugh, A.; Linke, M.J.; Cushion, M.; Collins, M.; Ananthula, H.K.; Sallans, L.; Desai, P.B.; Wiederhold, N.P.; Fothergill, A.W.; Kirkpatrick, W.R.; Patterson, T.; Wong, L.H.; Sinha, S.; Giaever, G.; Nislow, C.; Flaherty, P.; Pan, X.; Cesar, G.V.; de Melo Tavares, P.; Frases, S.; Miranda, K.; Rodrigues, M.L.; Luberto, C.; Nimrichter, L.; del Poeta, M.; “Identification of a New Class of Antifungals Targeting the Synthesis of Fungal Sphingolipids” MBio, 2015, 6(3), e00647-15

Moorthy, G.; Sallee, F.; Gabbita, P.; Zemlan, F.; Sallans, L.; Desai, P.B.; “Safety, Tolerability, and Pharmacokinetics of 2‑Pyridylacetic Acid, a major metabolite of betahistine, in Phase 1 dose escalation study in subjects with ADHD” Biopharm. Drug Dispos., 2015, 36, 429-439

Mummadisetti, M.P.; Frankel, L.K.; Bellamy, H.D.; Sallans, L.; Goettert, J.S.; Brylinski, M.; Limbach, P.A.; Bricker, T.M.; “Use of protein cross-linking and radiolytic footprinting to elucidate PsbP and PsbQ interactions within high plant Photosystem II” Proc. Natl. Acad. Sci., 2014, 111, 16178-16183

Frankel, L.K.; Sallans, L.; Bellamy, H.; Goettert, J.S.; Limbach, P.A.; and Bricker, T.M.; “Radiolytic Mapping of Solvent Contact Surfaces in Photosystem II of Higher Plants: Experimental Identification of Putative Water Channels within the Photosystem” J. Biol. Chem., 2013, 288, 23565-23572

Abu, E.A.; Su, S.; Sallans, L.; Boissy, R.E.; Greatens, A.; Heineman, W.R.; Hassett, D.J.; “Cyclic Voltammetric, Fluorescence and Biological Analysis of Purified Aeruginosin A, a Secreted Red Pigment of Pseudomonas aeruginosa POA1” Microbiology, 2013, 159, 1736-1747

Sallans, L.; Giner, J-L.; Kiemle, D.J.; Custer, J.E.; Kaneshiro, E.S.; “Structural Identities of Four Glycosylated Lipids in the Oral Bacterium Streptococcus mutans UA159” Biochim. Biophys Acta (Molecular and Cell Biology of Lipids), 2013, 1831, 1239-1249

Frankel, L.K.; Sallans, L.; Limbach, P.A.; and Bricker, T.M.; “Oxidized Amino Acid Residues in the Vicinity of QA and PheoD1 of the Photosystem II Reaction Center: Putative Generation Sites of Reducing-Side Reactive Oxygen Species” PLoS ONE, 2013, 8, e58042

Frankel, L.K., Sallans, L., Limbach, P.A., and Bricker, T.M., “Identification of Oxidized Amino Acid Residues in the Vacinity of the Mn4CaO5 Cluster of Photosystem II: Implications for the Identification of Oxygen Channels within the Photosystem, Biochemistry, 2012, 51, 6371-6377

Reszka, K.J., Xiong, Y., Sallans, L., Pasula, r., Hassett, D., Britigan, B.; “Inactivation of the Potent Pseudomonas aeruginosa Cytotoxin Pyocyanin by Airway Peroxidases and Nitrite” Am.J.Physiol. Lung Cell. Mol. Physiol., 2012, 302, L1044-L1056

Solivio, M.J.; Nemera, D.B.; Sallans, L.; Merino, E.J., “Biologically relevant oxidants cause bound proteins to readily oxidatively crosslink at guanine” Chem. Res.Toxicol., 2012, 25, 326-336

Mugundu, G.M.; Sallans, L.; Guo, Y.; Shaughnessy, E.A.; Desai, P.B.; “Assessment of the Impact of CYP3A polymorphisms on the Formation of α-Hydroxy tamoxifen and N-Des-methyl tamoxifen in Human Liver Microsomes” Drug Metab. Dispos., 2012, 40, 389-396

Sallans, L.; Poole, J. S.; “On the photochemistry of 4-azidoquinoline 1-oxide: Structural elucidation of primary photoproduct” J. Mol. Struct., 2011, 1003, 41-46

Samineni, D.; Desai, P.B.; Sallans, L.; Fichtenbaum, C.J.; “Steady State Pharmokinetic Interactions of Darunavir/Ritonavir with Lipid Lower Agent Rosuvastatin” J. Clin. Pharmacol., 2012, 52, 922-931

Reszka, K.J.; Sallans, L.; Macha, S.F.; Brown, K.; McGraw, D.W.; Butsch Kovacic, M.; Britigan, B.E.; “Airway Peroxidases Catalyze Nitration of the β2-Agonist Salbutamol and Decrease its Pharmacological Activity” J. Pharmacol. Exp. Ther., 2011, 336, 440-449

Wang, L.; Harshman, S.W.;Liu, S.; Ren, C.; Xu, H.; Sallans, L.; Grever, M.; Byrd, J.C.; Marcucci, G.; Freitas, M. A., “Assaying Pharmacodynamic Endpoints with Targeted Therapy: Flavopiridol and 17AAG Induced Dephosphorylation of Histone H1.5 in Acute Myeloid Leukemia”, Proteomics, 2010, 10, 4281-4292

Solivio, M.J., Joy, T.J., Sallans, L., Merino, E.J.; “Copper Generated Reactive Oxygen Leads to Formation of Lysine-DNA Adducts” J. Inorg. Biochem., 2010, 104, 1000-1005

Massey J. B.; Pownall H. J.; Macha S.; Morris J.; Tubb M. R.; Silva R A; Gangani D.; "Mass spectrometric determination of apolipoprotein molecular stoichiometry in reconstituted high density lipoprotein particles" Journal of Lipid Research, 2009, 50, 1229-36

Xu, H.; Wang, L.; Sallans, L.; Freitas, M. A.; “A Hierarchical MS2/MS3 Database Search Algorithm for Automated Analysis of Phosphopeptide Tandem Mass Spectra”, Proteomics, 2009, 9, 1763-1770

Webster, R. P.; Macha, S.; Brockman, D.; Myatt, L.; "Peroxynitrite treatment in vitro disables catalytic activity of recombinant p38 MAPK" Proteomics 2008, 6, 4838-4844

Nguyen, N.T.; Sallans, L.; Kaneshiro, E.S.; “The Major Glycerophospholipids of the Predatory and Parasitic Bacterium Bdellovibrio bacteriovorus HID5" Lipids, 2008, 43, 1053-1063