Marsha J. Lewis | Creating a “Designer” Protein


Explaining my Research

Protein are specialized microscopic machines. Proteins in our body have many functions including enzymes, structural support, signaling, storage. Scientists can design a protein with a specific function in mind.  There are many proteins on the market that have been successfully engineered to be medicines, such as the plasminogen activator protein, which successfully breaks down blood clots in heart attack and stroke patients.  Yet, there are still many unanswered questions about what protein functions can be engineered and how to efficiently engineer a protein function. For my PhD thesis I investigated how to engineer a new function into a unique protein with two related functions.  I used directed evolution to engineer a signaling protein in bacteria. The signaling protein has two functions: one part of the protein recognizes a signal and the other part catalyzes a reaction after the signal is received.  In my thesis, I asked if the two protein functions could be engineered separately and then retain their interaction after reassembly. This could be important for constructing diagnostic tests or in an application that requires specific control over cause and effect. My thesis discovered that you can engineer a protein by parts; however, the critical interactions between the protein parts must be embedded as parameters in the engineering method. 

Currently, my research has stepped away from protein engineering. New medicines can be discovered systematically by screening engineered proteins or compounds for the desired medicinal quality or they can be obtained from nature.  Medicines discovered from nature are called “Natural Products”. My current research investigates natural products excreted by fungi isolated from native Texas plants for medicinal qualities. My research approach is unique as I provide an opportunity for undergraduate students to do the research through The University of Texas Freshman Research Initiative (FRI) program. We are evaluating compounds for neuro-regenerative, anti-bacterial, herbicidal, anti-fungal, and anti-tumor properties.

How did you become involved with “Present your PhD Thesis to a 12 year-old” project?

I heard about the project through my colleague, Dr. Greg Clark.  I really like all aspects of this project!  I think it is exciting to communicate high level research to middle school kids.  It is important to show kids that research is about discovery, problem solving, and creativity and it is an attainable career for anyone interested.  I also like the aspect of giving graduate students an opportunity to communicate their research. I think many who work in research lose public support due to their inability to communicate what they are doing and why it is important in straight-forward, everyday language.

What is your goal introducing such a project/topic to young students?

My goal is to provide kids a glimpse of what cutting edge research looks like and show them it is exciting, understandable, and full of opportunities!  I hope that a glimpse of a potential future will motivate them in the present to build a solid foundation in school.  Young students are searching for themselves and have so much potential yet so many distractions.  They are eager to learn. Personally, I focus on the rural schools where the young students have fewer opportunities to meet and talk to active scientists.

Marsha Lewis

About the Ph.D. Thesis

Engineering Peptide Detection and Allosteric Activation

Creating a “Designer” Protein

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