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Photo by Carol Petersen |
A mystery involving algae has engaged Sabeeha Merchant in research for years. |
Two decades in search of answers
BY Stuart Wolpert
UCLA Today
When a fire shut down the laboratory where biochemist Sabeeha Merchant was conducting molecular biology research as a Harvard postdoctoral scholar in the 1980s, she decided to spend her free time in a library, reading scientific research papers. One of the studies she read puzzled and surprised her.
The study showed that algae could grow without copper, a nutrient essential for photosynthesis. She decided to pursue this mystery, not realizing that she would spend two decades searching for answers.
“The algae made a backup iron-containing protein that served the same function as the copper protein,” said Merchant, who joined UCLA’s faculty in 1987. “If you give them copper, they will use it, but if you take the copper away, they figure out a way around it. Many species of algae can do this switch. Somehow the algae know how much copper is present, but how do they know? They must have a way of measuring the copper; there must be an unknown mechanism. I wanted to learn what that mechanism is and how it works.”
She started to conduct research at the molecular level, and over the years, she has largely succeeded in solving this mystery. Indeed, last December, the Proceedings of the National Academy of Sciences published the results of a major research effort by her laboratory. She has identified in cells a specific protein molecule that she believes responds to whether copper is present. She studies the molecule in a green alga called Chlamydomonas, which scientists use as a model for researching photosynthesis in plants. The molecule is a critical element of the mechanism that creates the backup pathway, she said.
While the protein contains 1,232 amino acids, only a tiny portion of it, approximately 70 amino acids, may be involved in binding copper, Merchant said.
“Somehow copper is changing the properties of this region of the protein,” said Merchant, who is also associate director of UCLA’s Molecular Biology Institute and chair of the molecular biology interdepartmental Ph.D. program. “Exactly how the 70-amino-acid region acts is not yet known. How is the switch turned on? We hope to learn answers to these questions.”
For her efforts, Merchant will be honored April 23 with the Gilbert Morgan Smith Medal from the National Academy of Sciences at a ceremony in Washington, D.C.
The award is icing on the cake for someone who had “no idea” what she was going to do in life, the biochemist said.
Testing equally well in the humanities and in the sciences at her all-girls school in Bombay, India, Merchant was placed on the science track and continued that trend after moving to tiny Whitewater, Wis., with her family in 1977.
“I was never interested in the blood-and-guts aspect of medicine, so I went into biochemistry,” she said. “Studying the process of algae allows you to address problems that are relevant to human health, but also things that are relevant to the environment or to agriculture. … I kind of drifted into it; it wasn’t really planned. But that’s how a lot of research goes. You don’t know what’s coming around the corner.”
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