Bradley S. Evans,

PhD

Director, Proteomics and Mass Spectrometry Facility

Gardening was a Constant

Growing up in an army family, Brad Evans moved around.

“We lived in northwest Louisiana, San Antonio Texas, northeastern Alabama, Oahu, Hawaii, but I always kept a little garden. I learned it from my grandfather. They had a big garden in Coushatta, Louisiana. We grew watermelons, strawberries, tomatoes, okra, peppers, among other things.”

Even as a young boy, he was fascinated by biology. “Cells, genes. All these things going on in a world that is much smaller than we can see.” Today, Brad is a PhD biochemist, principal investigator, and director of the Proteomics and Mass Spectrometry Facility (PMSF) at the Danforth Center.

Proteo-What?

The PMSF is a bio-analytical lab, measuring metabolites, proteins, the building blocks of the cells. Proteomics is the study of proteins. Mass spectrometry is an analytical tool for measuring the mass-to-charge ratio for molecules in a sample—a way to identify compounds. Plants produce a vast array of specialized metabolites, or natural products that communicate with other organisms, defend against pathogens and herbivores, attract pollinators, and deter pests. These could be developed into chemicals and medicines useful to humans. For many experiments biologists perform, it’s hard to know if they have affected the change they are trying to achieve. PMSF can provide the analysis to validate the work of Danforth Center scientists.

If you are interested in improving nutrition or commercial qualities of crops (oil, protein, natural product, medicine, etc.), you have to have some way to measure if you’ve been successful or not. If you’re interested in knowing how growth correlated to environment, you need molecular characterization. These are all questions the PMSF can answer.”

Improved Instrumentation

The field of mass spectrometry, Brad has witnessed the proliferation and lowering in price of high-resolution mass instruments since he first started, thanks largely to the innovation of the Orbitrap, a type of Fourier transform mass spectrometer (FTMS). “When I was first in graduate school, there was only one type of FTMS instrument available and those were cost-prohibitive for most labs. There was a dependence on expensive consumables—liquid helium—and a very expensive super-conducting magnet made of rare earth minerals. But the new technology, Orbitrap, relies on an electrostatic rather than magnetic field. All you need is power. It’s been revolutionary.”

Research to Speed the Science

The Evans Lab is continually working on development of methods to expand the depth of information the can be gleaned using mass spectrometry.  Together with 30 other labs, they are working to develop tools and technology for automated data analysis for metabolites. Staying at the cutting-edge of this field speeds the research of Danforth Center scientists, so that we can feed the world while preserving our planet.

On the valuable service his Core Facility provides

"If you are interested in improving nutrition or other qualities of plants, you have to have some way to measure if you’ve been successful or not."

Fun fact:

He enjoys the science of fermentation and brews beer at home, mostly IPAs and stouts.

On the valuable service his Core Facility provides

"If you are interested in improving nutrition or other qualities of plants, you have to have some way to measure if you’ve been successful or not."

Fun fact:

He enjoys the science of fermentation and brews beer at home, mostly IPAs and stouts.

Get in touch with Bradley S. Evans

Research Team
Research Summary

The Evans laboratory uses high-performance mass spectrometry, proteomics, and metabolomics for connecting molecular phenotypes with the macroscopic form and function of organisms.

Bradley S. Evans

Director, Proteomics & Mass Spectrometry Facility

Kranthi Chebrolu

Postdoctoral Associate

Xiaohong Feng

Research Associate

Jonathan Mattingly

Intern

Shin-Cheng Tzeng

Staff Scientist

Bradley S. Evans

Director, Proteomics & Mass Spectrometry Facility

Kranthi Chebrolu

Postdoctoral Associate

Xiaohong Feng

Research Associate

Jonathan Mattingly

Intern

Shin-Cheng Tzeng

Staff Scientist

Technology Development

Over the last few decades, mass spectrometry has developed into the technique of choice for analysis of proteins and metabolites.  The Evans Lab is continually working on development of methods to expand the depth of information the can be gleaned using chromatographic separations and mass spectrometry.  Some examples of ongoing work in the lab include:

  • Differential mobility separation of isomeric/isobaric species
  • Multidimensional chromatographic separations for increased metabolomic coverage
  • Sample preparation methods for quantitative phosphoproteomic analysis
  • Automated data analysis tools for untargeted metabolomics analysis

 

Inositol Polyphosphates

Inositol (poly)phosphates (IPs) are important cellular signaling molecules in eukaryotic organisms having diverse roles from calcium signaling pathways to telomere maintenance.  There are theoretically 63 different isomers of IPs possible, not considering the pyrophosphates.  So far, over 30 IP isomers have been found in eukaryotic cells.  In spite of the important roles that IPs play in cellular function and the many possible isomers known to exist, robust methods for detection and quantitation of these very low abundance metabolites exist.  In collaboration with the Umen Lab and the Allen Lab at the Danforth Center, the Evans Lab is developing sensitive and selective mass spectrometric methods that use differential mobility spectrometry in conjunction with chromatography to separate and quantify IP isomers.

 

Natural Products

Plants produce a vast array of specialized metabolites, or natural products that communicate with other organisms, defend against pathogens and herbivores, attract symbionts and deter pests. These metabolites are produced by both wild and cultivated species, including important crops.  Plant natural products are important for plant and crop defense and can also be used as agricultural chemicals, fine chemicals and medicines.  Understanding the genes responsible for production of plant specialized metabolites will be useful for maximal exploitation of these metabolites for crop protection and other human uses. However, linking the chemical phenotype (chemotype) of a plant to its underlying genotype is arduous and slow. The conventional process begins with purifying chemical compounds from the plant, determining their structures, and using reverse genetics approaches to identify the relevant biosynthetic genes.  Finally, in vivo and in vitro studies are required to study gene and pathway function in the plant.  There are serval hurdles in applying this workflow.  First, the chemical compound must be produced constitutively or at least under conventional laboratory conditions.  Second, the compound(s) of interest must be flagged as interesting using a biological or chemical assay. Third the compound(s) must be de-replicated—in other words it must be determined if the biological activity or chemical signature comes from a compound that has already been characterized or if it comes from a novel compound, a process that has historically been very time consuming.  Finally, validation requires genes coding for putative biosynthetic enzymes to be disrupted and/or cloned and heterologously expressed.  The Evans Lab is actively working on methods using high-resolution accurate-mass mass spectrometry for quick dereplication of natural product extracts as well as methods for accurate structural classification and comparative analyses of plant metabolomes.