Donald Caspar

Donald L. D. Caspar
Born	(1927-01-08)January 8, 1927
Died	November 27, 2021(2021-11-27)(aged 94) Tallahassee, Florida
Nationality	American
Other names	Don Caspar
Citizenship	American
Alma mater	Cornell University(BA) Yale University(PhD)
Awards	Fellow of the Biophysical Society Award
Scientific career
Fields	Structural biology
Institutions	California Institute of Technology Florida State University Brandeis University Birkbeck, University of London King's College London
Thesis	The Radial Structure of Tobacco Mosaic Virus(1955)
Doctoral advisor	Ernest C. Pollard
Other academic advisors	Max Delbrück Rosalind Franklin
Doctoral students	Stephen C. Harrison
Other notable students	Kenneth Holmes(postdoctoral researcher)
Website	Florida State University page

Donald L. D. Caspar(January 8, 1927 - November 27, 2021) was an Americanstructural biologist(the very term he coined) known for his works on the structures of biological molecules, particularly of thetobacco mosaic virus.He was an emeritus professor of biological science at the Institute of Molecular Biophysics,Florida State University,and an emeritus professor of biology at the Rosenstiel Basic Medical Sciences Research Center,Brandeis University.He has made significant scientific contributions in virus biology, X-ray,neutronandelectron diffraction,and protein plasticity.

Caspar completed his BA in physics fromCornell Universityin 1950. He joinedYale Universityfrom where he earned his PhD in biophysics in 1955.He was supervised byErnest C. Pollard.His thesis was on the structure of tobacco mosaic virus (TMV) titledThe Radial Structure of Tobacco Mosaic Virus.While waiting for his degree he worked underMax Delbrückat theCalifornia Institute of Technologyas post doctoral student.He worked withJames D. Watson,with whom he had close professional association throughout his career. After receiving his PhD, he went to England having been awarded a fellowship atKing's College LondonunderRosalind Franklinand during 1955–1956 worked with her atBirkbeck Collegein London. Their meeting was fruitful both personally and professionally. He remained one of Franklin's closest friends during her brief lifetime. In 1956 he and Franklin published individual but complementary papers in the March 10 issue ofNature,together showing that TMV was a hollow rod, rather than a solid structure as generally believed. They also demonstrated thatRNAin TMV was wound along the inner surface of the hollow virus.He was not a particularly enthusiastic writer; as a result, Franklin had to write every word of his paper.

At Birkbeck one of his colleagues wasAaron Klugwith whom he developed research collaborations throughout his career.In 1962, they introduced the concept of quasi-equivalence to account for the arrangement ofproteinson the surface oficosahedralvirus particles.Caspar-Klug theoryhas played an important part in shaping the subsequent study of viruses and othermacromolecular assemblies.The original concept was based mainly onelectron microscopestudies, and has now been refined to take account of the atomic resolution structure ofviruses,and other details ofprotein–protein interactionsthatcrystallographyhas elucidated. Quasi-equivalence continues to be an important component of the philosophical basis for how we think about macromolecular assemblies.

In 1994 Caspar received theGuggenheim Fellowships.He was a Fellow of theAmerican Academy of Arts & Sciences.He was elected a member of the Biophysics and Computational Biology section of theNational Academy of Sciencesin 1994.He received the first Fellow of theBiophysical SocietyAward in 2000.

External links

• Florida State University faculty profile