Exploring the Seas of Science

by Danielle LaVaque-Manty

David Sherman grew up immersed in science. As a boy he had a microscope, given to him by his father, who was a physician. "We used to go and get pond water and look under the microscope at the various moving things like Paramecium and so on," he says.

He also had a chemistry set, provided by his mother, a high school chemistry teacher. "We'd actually do things at home like generate hydrogen gas from zinc and concentrated sulfuric acid, and collect the hydrogen in a little test tube, and light a match. It'd make this loud sound—that was pretty exciting."

Given this family background, he thinks it's unlikely that anyone who knew him when he was younger would be surprised to learn that he has become a scientist. Anyone might be surprised, however, by the particular path Sherman's career has taken, combining not only chemistry and microbiology, but also marine exploration.

As an undergraduate at UC-Santa Cruz, he did research with his adviser, Phil Crews, which included field work. "I did a lot of scuba diving as an undergraduate, and sample collection and lab work on these materials." In graduate school he studied synthetic organic chemistry, learning to build molecules that replicate natural products. After completing his Ph.D., he chose an unusual path, pursuing a post-doc in bacterial genetics, "which was just not done, let's put it that way."

He wanted to understand how microorganisms produced the molecules he'd been learning to replicate—"In other words, I was interested in understanding how microorganisms did synthetic chemistry"—so he went to England and joined the lab of David Hopwood, who had already identified the genetic blueprint similar to those responsible for antibiotics such as erythromycin and tetracycline. There, Sherman learned to manipulate bacteria genetically in order to learn "how they produce these amazing molecules."

He became a faculty member in the microbiology department at the University of Minnesota, where he continued to work at the interface of microbiology and organic chemistry. Field work, which he had enjoyed as an undergraduate, became part of his research program a few years later after he saw a paper by his undergraduate adviser, Phil Crews, and sent him an email that led to their renewed collaboration.

Crews invited him to travel to Papua New Guinea, where Sherman began to develop a project isolating bacteria from sediments and sponges and other sources rich in microorganisms, many of which produce "drug quality molecules." The idea was that these marine organisms would offer genetic and chemical diversity not seen in terrestrial sources. "There was a growing realization that the marine environment had been completely under-explored in terms of microbiology."

His first expedition to Papua New Guinea took place in 2000. These days, he travels to Costa Rica and Panama as well, accompanied by his graduate students. They spend ten days at a time on a research vessel Sherman's team shares with two other groups, one from Scripps Oceanographic and the other from UC-Santa Cruz, where Phil Crews still teaches.

These research teams require legal permission to do their exploring, and some countries refuse to admit them, while others allow researchers in but refuse to let them take anything out. Australia, for example, has made the Great Barrier Reef off limits to anyone who isn't Australian.

Doing field work is exciting, Sherman says. "We begin our work with environmental samples. We're not buying them from a chemical catalogue. We're not just taking laboratory cell lines and working with those. We get to go and collect new materials."

The goal of all this collecting is to discover new bioactive agents with medical applications. "We're learning new and interesting science," he says, "but we're also able to do something with it, perhaps speed up the process of discovering a new anti-cancer drug."

Sherman came to the University of Michigan as the John Gideon Searle Professor in Medicinal Chemistry in 2003. "I was really impressed by Michigan in terms of the faculty here, the student quality, and the resources this university has, which are extraordinary," he says. "That all added up to the idea that this would be a great place to be. And it is." Soon after his arrival, he agreed to help develop the Center for Chemical Genomics at the Life Sciences Institute as well, and became the Center's director in 2004.

The oldest of Sherman's three children, an eighteen year-old daughter, is working in his lab at the LSI during the summer of 2007. She also recently accompanied him on a research trip to Papua New Guinea. "And she really got it," he says. "You never know what's going to happen when you take one of your children somewhere that you think is just the most incredible place. And Papua New Guinea is one of those places for me."

While he loves the natural beauty there, it's the people that intrigue him the most. "It's one of the few places you can go which is untouched. You can, in remote areas, see indigenous people living in traditional villages and traveling the seas in outrigger canoes...you have this feeling that you're going to a completely different world."

Sherman's hobby? He likes to read about explorers.