Hruby’s primary focus at the University of Arizona, where he is Regents professor of chemistry, is peptides — small proteins such as hormones and neurotransmitters that carry messages from one cell or part of the body to another.
“We’re interested in the biological functions, but in particular we’re looking at compounds that have an effect on behavior — reactions to pain or addiction, feeding behavior, sexual behavior, fear/flight reflexes and short-term and long-term learning,” he said.
One hormone he has worked with stimulates tanning in humans — that is, helps cause skin cells to produce melanin. Alpha-MSH (for melanocyte stimulating hormone) also helps chameleons adapt their color to their environment and snowshoe hares to change coats according to the season.
Hruby’s research team has discovered alpha-MSH also stimulates receptors in the brain that turn down the urge to eat. “And we found that very small changes in the structure of the hormone can make very large changes in its behavioral effect,” he said. “So nature is obviously poised to make changes in behavior. Now the question is exactly how do such small changes do that?”
Hruby received his undergraduate degree from the University of North Dakota in 1960 and his Ph.D. in 1965 from Cornell University. He is a member of the ACS divisions of organic and medicinal chemistry.
Hruby came to science in an unusual way, however. “I grew up in a very religious family, and as a boy I’d always ask these questions like ‘With the 10 Commandments and all, why do people behave so badly?’,” he said. “Then in high school I had a physics teacher who knew I was interested in the relationship between knowledge and ethics and behavior, and he told me science was where all these modern questions were going to be answered. He was truly prophetic.”
The ACS Ralph F. Hirschmann Award in Peptide Chemistry is sponsored by Merck Research Laboratories.