John Turk, MD, PhD, a pioneer in mass spectrometry research and a deeply respected faculty member for more than 40 years at Washington University School of Medicine in St. Louis, died May 26, 2021, in Eureka, Mo., after a brief illness. He was 73.
The Alan A. and Edith L. Wolff Professor of Endocrinology, Turk was a pioneer in lipid biochemistry, defining key mechanisms of phospholipid signaling that contribute to diabetes. His work first drew international attention when he used tandem mass spectrometry to determine the molecular structures of complex lipids such as phosphatidylcholines, one of the fundamental lipid building blocks of cells.
Also a professor of pathology & immunology, Turk was among the discoverers of a phospholipase enzyme, iPLA2b, that participates in the control of insulin secretion and the survival of pancreatic beta cells. He and his collaborators demonstrated that this enzyme also is involved in cell proliferation, cell death, membrane biochemistry, and a wide range of conditions including infertility, metabolic syndrome, chronic inflammation, and neurodegenerative disorders such as Parkinsonism. His work has been held in such high regard by the metabolic disease community that he twice received a National Institutes of Health (NIH) MERIT Award, a prestigious honor designed to provide stable, long-term funding to exceptional, experienced investigators.
“John Turk was a distinguished faculty member for more than 40 years at the School of Medicine,” said Victoria J. Fraser, MD, the Adolphus Busch Professor of Medicine and head of the Department of Medicine. “He had tremendous expertise in mass spectrometry and was a well-funded, well-respected investigator and lab director for many years. He also was a compassionate clinician and educator. He cared deeply about this university, and he represented it so very well.”
For most of the time Turk was on the faculty, he directed the Department of Medicine’s NIH-funded Mass Spectrometry Core Facility, providing scientific support to hundreds of investigators interested in the analysis of complex molecules associated with human diseases. An active clinician and teacher, he also was an attending physician for the department and taught toxicology to pathology residents throughout his career.
A lifelong St. Louisan, Turk was raised in the area, earned his bachelor’s degree at Washington University in 1970, and went on to earn medical and doctoral degrees at the School of Medicine in 1976. His internship in internal medicine was at the University of Chicago, but he returned to Washington University to complete his resident training. He completed a fellowship in clinical pharmacology at Vanderbilt in 1982, but then returned to his hometown once again, to join the School of Medicine faculty.
Turk was in his third term as a member of the editorial board of the Journal of Biological Chemistry. He was an elected member of the American Society of Clinical Investigation and the Association of American Physicians, and he received numerous honors over his career, among them his endowed professorship in 2014.
Turk grew up picking persimmons with his family and used them to bake bread. He continued this tradition at the School of Medicine, making gifts of freshly made persimmon bread to scores of faculty and staff every holiday season.
“Dr. Turk was extremely dedicated to Washington University,” said Clay Semenkovich, MD, the Irene E. and Michael M. Karl Professor, and director of the Division of Endocrinology, Metabolism and Lipid Research. “He was a great scientist, a devoted teacher and a compassionate mentor who would always stop whatever he was doing to help other scientists. He will be missed for his wisdom and kindness.”
He is survived by his beloved companion, Carol Thompson; ex-wife, Alice Turk; daughter, Amy Turk (Justin Prien); son, Andrew Turk; brother, Jim Turk; and three grandchildren.
Visitation will be 3 to 8 p.m. Thursday, June 3, at Bopp Chapel, 10610 Manchester Road, Kirkwood, Mo. Funeral services will be at Bopp Chapel at 11 a.m. Friday, June 4.