Summer Student Research | Spotlight

Shedding light on the study of plant enzymes

With NSF support, Mariah Rincon experiments with scientific research

Pictured: (l-r) Mariah Paula Rincon and Luis Gonzalez.
Pictured: (l-r) Mariah Paula Rincon and Luis Gonzalez looking at a plant enzyme sample stored in a purified petri dish.

Sowing the seeds toward a career in scientific research, Mariah Paula Rincon spent 10 weeks this summer in one of Cal State L.A.’s advanced science labs, analyzing the photosynthetic enzymes found in maize, sugarcane and other highly productive plants known as C4 plants.

Looking basically at the temperature dependence of the interaction between the enzyme phosphoenolpyruvate carboxilase (PEPc) and the small activating molecules that bind to the photosynthetic enzymes, Rincon participated in CSULA Chemistry Professor Scott Grover’s research project, “Molecular Aspects of Enzyme Regulation.” The project was funded by the National Science Foundation for a Research Experience for Undergraduates (REU) Program at Cal State L.A. that introduces undergraduates to chemical analysis and field study.

Working alongside CSULA graduate student Luis Gonzalez and Project SEED scholar Brittany Cortez, Rincon used a spectrophotometer—a lab instrument that measures light absorption at different wavelengths—to determine if changes in temperature would have an impact on the glycine-activated reaction of PEPc, which traps atmospheric carbon dioxide and is a key component of a particularly efficient pathway of photosynthesis in C4 plants.

What is an enzyme? An enzyme is a protein catalyst that accelerates the rate at which a specific chemical reaction in the cell, like the breakdown of a sugar molecule during digestion, or the synthesis of a molecule of DNA, occurs.

What is glycine? Glycine is one of the 20 types of amino acids used by cells to build proteins. It is also a metabolic intermediate in some photosynthetic cells.

(source: Scott Grover, CSULA)

According to Rincon, a microbiology major from the University of Los Andes in Colombia, “The temperature sensibility of PEPc’s response to glycine will provide evidence of whether or not a large structural rearrangement is occurring when glycine docks on the surface of the enzyme. Preliminary evidence indicates that glycine is a more powerful activator at higher temperatures, consistent with the notion that activation requires an energy-dependent rearrangement of the enzyme structure.”

Professor Grover said, “Our goal is to understand, at a molecular level, how activators and inhibitors interact with and regulate plant enzymes that utilize atmospheric carbon dioxide. This study is essential since plants form the base of the food chain in the ecosystem, and photosynthesis in plants ultimately provides all the energy and carbon-containing molecules to sustain all life on Earth.”

Rincon, who will transfer to Cal State L.A. in the fall, said, “I am excited to have received this hands-on experience in research through the REU summer program at Cal State L.A.” She added, “I was attracted to Cal State L.A. because of the credentials of the professors who teach here, along with the opportunity for undergraduates to be involved with research very early in their careers.” She indicated that her goal is to pursue a Ph.D. and to find cures for certain diseases.

Pictured: (l-r) Mariah Paula Rincon, Brittany Cortez and Luis Gonzalez.
Pictured: (l-r) Mariah Paula Rincon, Brittany Cortez and Luis Gonzalez in the 4-6 Degrees Room in La Kretz Hall.

For Cortez, this is also her first time to work in a science lab and, specifically, on a college campus. Cortez, a 15-year-old from Lincoln High School, said that she was encouraged by her chemistry teacher to participate in the Project SEED summer research program at Cal State L.A. She said, “I am very interested in science, so I took advantage of this opportunity. I also get paid a stipend.”

Cal State L.A.’s Chemistry & Biochemistry REU Program gives research opportunities to community college students from the Los Angeles region. The program introduces students to research early in their academic careers, so they will be motivated to continue pursuing the chemical sciences.

Funded by the American Chemical Society, Project SEED integrates high school students for eight weeks in the summer into active research groups under the direction of chemistry and biochemistry faculty members at Cal State L.A. The students select the nature and scope of the research project, which is then arranged to suit each student’s level and interests through consultation between the adviser and the student.

The team of three—Rincon, Cortez and Gonzalez—will present the results of their summer project at the Summer Student Research Poster Presentations Friday, Aug. 20, 1 p.m., at the first-floor lobby of CSULA’s Physical Sciences building.

The Friday event will also include poster presentations by other students in the REU program and Project SEED, along with participants in the National Institutes of Health-Summer Bridges Program. For more details, call Scott Nickolaisen, Chemistry and Biochemistry Dept., at (323) 343-2382.

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