David Harker (October 19, 1906 – February 27, 1991) was an American medical researcher who according to the New York Times was "a pioneer in the use of X-rays to decipher the structure of critical substances in the life process of cells".
He is also well known for Harker–Kasper inequalities (statistical relationships between the phases of structure factors), which he devised in collaboration with John S. Kasper. Harker made seminal discoveries in the field of chemical crystallography.
His lab solved the structure of the pancreatic enzyme ribonuclease A, the third protein structure ever solved by protein crystallography. Harker was a member of the National Academy of Sciences, director of the protein structure program at the Polytechnic Institute of Brooklyn, director of the Center for Crystallographic Research at Roswell Park Cancer Institute (RPCI), and the head of the crystallography division of General Electric. After retirement from RPCI in 1976, he joined the Hauptman-Woodward Medical Research Institute (HWI), then known as the Medical Foundation of Buffalo. He remained there until his death in 1991. His research interests while at HWI turned towards mathematical aspects of crystallography, including color space groups and infinite polyhedra.
- New York Times:Obituaries:Dr. David Harker, 84, a Pioneer in Use of X-Rays in Cell Research, By WALTER SULLIVAN, Published: March 2, 1991
- National Academies Press:David Harker, By Herbert A. Hauptman
- Hauptman-Woodward Medical Research Institute, PIONEERS OF SCIENCE AWARDEES - 2011
- Kartha G, Bello J, Harker D (1967). "Tertiary Structure of Ribonuclease". Nature. 213: 862–865. Bibcode:1967Natur.213..862K. doi:10.1038/213862a0. PMID 6043657.
- New York Times:Crystal Research Planned, February 22, 1964
- New York Times:NEWS OF PEOPLE IN THE BUSINESS WORLD, January 3, 1949