PhD · Chemistry · Indiana University Bloomington

Matthew Davisson

PhD · Chemistry · Indiana University Bloomington

From an early age I was drawn to the natural world — spending time outdoors, observing wildlife, and wondering how living things worked at levels invisible to the naked eye. That childhood fascination with nature’s complexity grew alongside a deepening interest in science, eventually leading me to pursue chemistry and biochemistry as a way to understand the molecular logic underlying biological systems. I was particularly captivated by the idea that organisms, through millions of years of evolution, had already solved many of the problems that medicine and pharmacology are still working to address.

Reading Venomous: How Earth’s Deadliest Creatures Mastered Biochemistry by Christie Wilcox crystallized this perspective for me. Wilcox’s exploration of how venomous animals evolved extraordinarily precise biochemical tools — proteases, ion channel blockers, receptor-targeted peptides — that are now being harnessed to treat human disease made clear that nature is not just an inspiration but an active partner in drug discovery. That book, alongside my doctoral research into secreted proteolytic enzymes in Bacillus subtilis, has shaped my conviction that the most promising therapeutic molecules may already exist in snake venoms, fungal bioactive compounds, and plant metabolites — waiting to be identified by the right combination of proteomics, mass spectrometry, and biochemical characterization.

PhD Thesis Research

Comparative N-terminomic analysis of extracellular protease substrates in B. subtilis

Secreted proteins from Bacillus subtilis were analyzed to identify novel proteolytic modifications using a comparative N-terminomics approach. By examining the wild-type strain alongside a mutant lacking all seven major extracellular proteases (Δ7), 139 previously documented and 129 novel proteolytic sites were identified across 46 proteins. Three polysaccharide-degrading hydrolases were identified with novel cleavages separating their catalytic domains from carbohydrate-binding modules, revealing a previously undescribed mechanism of proteolytic enzyme remodeling in the B. subtilis secretome.
01

N-terminal guanidinylation workflow for secretome N-terminomics

Developed and applied a COFRADIC-like N-terminomics workflow using 1H-pyrazole-1-carboxamidine (HPCA) to guanidinylate free primary amines on secreted B. subtilis proteins prior to tryptic digestion. Unlike SMTA amidination, HPCA labeling converts lysine ε-amines to homoarginine, preserving trypsin cleavage sites and improving peptide coverage. Following labeling, proteins were digested with trypsin, fractionated by HpHRPLC into 12 fractions, and analyzed by nanoLC-MS/MS on an Orbitrap Fusion Lumos. Workflow validation achieved 92% labeling efficiency at known signal peptidase cleavage sites.

HPCA guanidinylationN-terminomicsHpHRPLC fractionationOrbitrap Fusion LumosnanoLC-MS/MS
02

Comparative secretome profiling of wild-type vs. Δ7 protease-deficient B. subtilis

Performed a quantitative comparative proteomics study between B. subtilis strain 3610 and its Δ7 derivative lacking all seven major extracellular proteases (AprE, NprE, Bpr, Epr, Mpr, Vpr, WprA). LFQ using Proteome Discoverer 2.5 and Sequest HT identified 1,174 proteins representing 28% of the proteome. Student’s t-test analysis of 69 consistently observed secreted proteins identified 30 with statistically significant abundance differences between strains.

Label-free quantificationComparative proteomicsProteome Discoverer 2.5Sequest HTTCA precipitation
03

Identification of novel proteolytic sites & protease substrate mapping

129 novel proteolytic cleavage sites were identified across 46 proteins. Of these, 47 WT-exclusive sites implicated 17 proteins as substrates of the seven extracellular proteases. Domain-separating cleavages were identified in AmyE, EglS, and Abn2, where proteolysis separated catalytic glycoside hydrolase domains from carbohydrate-binding modules. Structural homologs YncM and YrpD (96% sequence identity) displayed conserved cleavage motifs, providing a candidate sequence for protease specificity analysis.

Novel cleavage site discoveryProtease substrate identificationDomain architecture analysisAlphaFold / PDB

Where I want to go next

Building on my doctoral foundation in microbial proteomics, I am eager to pursue two interconnected research directions. Click either panel to explore further.

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Therapeutic Discovery from Natural Sources

Identifying bioactive compounds with drug potential

Nature has evolved an extraordinary diversity of proteins, metabolites, and bioactive compounds with precise biological activities. Select a natural source below to explore research directions and supporting literature.

🐍Venom proteins→
🍄Fungal bioactive compounds→
🔗BioID & protein interactome mapping→
🚧 Under Construction 🧬

Biomarker Identification via Mass Spectrometry Imaging

Spatially resolved molecular mapping in patient tissues

Mass spectrometry imaging enables untargeted, spatially resolved detection of proteins, peptides, lipids, and metabolites directly within tissue sections — preserving the anatomical context of molecular distributions for disease biomarker discovery.

Content coming soon

Technical Skills

Laboratory expertise

Skills extracted directly from doctoral thesis research and validated through hands-on experimental application.

⚗️Mass Spectrometry & Instrumentation
Orbitrap Fusion Lumos Tribrid MSLTQ Ion Trap (Thermo Finnigan)ESI-Q-TOFElectrospray Ionization (ESI)nanoLC-MS/MSData-Dependent Acquisition (DDA)Data-Independent Acquisition (DIA)Collision-Induced Dissociation (CID)High Energy CID (HCD)Tandem MS (MS/MS)Top-down proteomicsBottom-up proteomicsb1 ion detection & stabilization
🧪Liquid Chromatography
Reverse-Phase LC (RPLC)High pH RPLC (HpHRPLC)Strong Cation Exchange (SCX)2D Liquid Chromatography (2D-LC)nanoLC (easyNanoLC 1200)C18 column chromatographyC4 reverse-phase chromatographyPeptide desalting (C18 ZipTip & IDEX)Fraction concatenationKinetex EVO C18 fractionation
🔬N-Terminomics & Chemical Labeling
N-terminal guanidinylation (HPCA/TAGS)SMTA amidination2-Pyridinecarboxaldehyde (2-PCA) labelingCOFRADIC / ChaFRADIC enrichmentTAILS (Terminal Amine Isotope Labeling)CHOPS enrichmentPrimary amine labeling chemistryPositive & negative N-terminal enrichmentHomoarginine-directed trypsin digestionSMTA synthesis from thioacetamide
🧫Protein Biochemistry & Sample Preparation
TCA protein precipitationTrypsin digestion (MS-grade)Bradford assayUV-Vis spectrophotometryNanodrop quantificationMWCO ultrafiltration (Amicon)Vacuum centrifugation / Speed-VacLyophilizationSDS-PAGEZymographyGuanidine HCl denaturationSemi-tryptic digest workflows
🦠Cell Culture and Related Techniques
Glycerol stock preparationCell growth curve measurementBacillus subtilis culturingHeLa cell culturingProtein precipitationProtein concentration from spent growth media
💻Bioinformatics & Data Analysis Software
Proteome Discoverer 2.5Sequest HT database searchMascot (Matrix Science)MSConvert / ProteoWizardUniProt Knowledgebase (UniProtKB)SignalP 6.0DeepLocPro 1.0Label-Free Quantification (LFQ)Target-decoy FDR validationTwo-tailed Student’s t-testVolcano plot analysisSemi-tryptic peptide database searchingAlphaFold structure interpretationPDB structure analysis

Get in touch

Interested in collaborating or discussing opportunities? I’d love to connect.