Vanderbilt student creates new procedure during summer internship at NIST

By Emily Waltz
February 24, 2003

In the early morning stillness, the empty lab echoed with Melanie Bernard's footsteps as she approached the experiment she had set up the night before. The shells of her choker necklace seemed tighter than usual. If crystals had formed in the tiny wells in the seven plates that she had filled, the Vanderbilt senior would have created a special test, called a screen, that would eliminate the thousands of experiments normally required to determine the molecular structure of members of a specific hemoglobin family, the special proteins that transport oxygen through the blood and give it its red color.

Melanie Bernard
Courtesy of Melanie Bernard
Melanie Bernard

The hemoglobin from her seven test subjects - a horse, a rabbit, a baboon, a human, a cow, a pig - were arranged on the counter in front of her. Bernard looked for crystals or "hits" in each drop of red liquid. Leaning over the plates she scanned the tiny wells and let her shoulders relax. Perfect crystals had formed in most of the wells, and she knew that more would form over the next two weeks.

Bernard, who is majoring in Biomedical/Electrical Engineering at Vanderbilt, created the hemoglobin screen during an internship last summer at the National Institute of Standards and Technology (NIST). Her screen is important because it is the first screen developed for a targeted family of proteins, and it will be used by NIST to accelerate the process of determining crystallization patterns for that protein family. The screen is only one step in the process of determining protein structure, but it reduces the thousands of crystallization experiments to a couple dozen, saving resources, time and money according to her advisor at NIST.

Bernard worked under the direction of Gary Gilliland, Biotechnology Division Chief at NIST and "a big cheese" in the world of protein crystallography, according to Bernard.
Gary Gilliland
Courtesy of Melanie Bernard
Gary Gilliland

Understanding the functions of proteins is especially useful now that scientists have mapped the human genome and the genome of an increasing number of other organisms. NIST, a global leader in setting standards of measurement, is responsible for contributing the 30,000 to 40,000 protein structures encoded by the human genome to its Protein Data Bank.

Bernard explained that her daily job at the NIST lab was to conduct experiments to determine what conditions make different proteins crystallize. Once scientists have a pure protein crystal, they can use a powerful technique called X-ray crystallography to determine its structure. When an X-ray beam passes through a crystal, it produces a complex pattern of light and dark spots on a detection screen. By analyzing the location and intensity of these dots, experts can reconstruct the type and position of the individual atoms that the crystal contains. Once a protein structure has been completely determined, this information is deposited in the Protein Data Bank.

Despite the importance of developing the hemoglobin screen, Bernard's reaction was one of relief rather than excitement - relief that all of her work hadn't been for nothing, she explained. Instead, it was her adviser who was excited. He was able to use Bernard's work in his lecture at the 19th meeting of the International Union of Crystallography in Geneva Switzerland.

"What I described in the talk was Melanie's work that involved reviewing all of the crystallization data concerning hemoglobins and related proteins. Melanie's screen was tested against a battery of different hemoglobins and proved quite successful," Gilliland said. He also noted that Bernard will receive recognition for her work in a paper that he will be submitting to the scientific journal Acta Crytallographica D.

Bernard was one of 102 students nationwide chosen to intern last summer at NIST, a federal agency located in Gaithersburg, Maryland. Bernard wanted to explore her career options with a summer internship.

Group photo of NIST interns
Courtesy of Melanie Bernard
Group photo of NIST interns

"I was wondering if life in a cubicle was how it was going to be," Bernard reflected upon her desk job the previous summer. In search of hands-on laboratory experience, Bernard applied to and was accepted at NIST to help develop screens for various proteins.

Bernard's initial project at NIST, however, was disappointing. "They started me out doing data entry because I had some computer programming experience and that wasn't what I had expected to do," she said. "But I asked my advisor, Dr. Gilliland, if there was something else I could do and he brought me over to his auxiliary lab at the University of Maryland."

Gilliland's lab in the Chemical Science and Technology department of NIST and at the University of Maryland specializes in the crystallization of biological macromolecules. The department has determined the three-dimensional crystal structures of thousands of molecules and has created a crystallization database to house and consolidate that information. Melanie's screen is based on information from this database, a recipe book for thousands of crystal structures.

Gilliland explained that understanding a protein's crystallization structure is especially useful for scientists when designing drugs for medicinal purposes. "HIV protease inhibitors for the treatment of AIDS are a good example of drugs that were developed using the structure-based drug design approach," said Gilliland. "Knowledge of the structure and function of the complete set of proteins is also critical to understanding the basic processes of life," he said.

Bernard at work
Courtesy of Melanie Bernard
Bernard at work

The internship included a stipend and housing in an apartment complex in Gaithersburg with the other students who were chosen for the internship. The housing situation made her experience quite social, according to Bernard, who said she spent a lot of time with the other students. "It was a pretty sweet deal," Bernard said, referring to the swimming pool and maid service in her apartment complex.

Students worked 9 A.M. - 5 P.M. every day in various labs at NIST. They also attended seminars each Friday to learn about the agency's current research projects. One seminar focused on NIST's development of autonomous robots that were used to search the World Trade Center after 9/11, Bernard said.

Bernard enjoyed her work at NIST and discovered the rewarding aspects of her field of study. "Each day is like a surprise to see if your experiment worked," she said. Bernard felt most satisfied with her internship when her advisor commented that he was impressed with her results and that he was glad she had complained about her initial data-entry job.

- VU -


Emily Waltz is a senior majoring in communications studies at Vanderbilt.

 


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