DNA Papers #9: Erwin Chargaff

Perspectives on Science

Episode 9 of the DNA Papers discusses a set of papers by the first scientist who made a sustained effort into uncovering the secret behind specificity of nucleic acids. The principle author, Erwin Chargaff, a European-American biochemist from Columbia University in New York, determined that the relative rations of the four nucleotide bases—A, T, G and C—were not present in all DNA in equal amounts as widely assumed, but rather, that they varied in proportion from one to another, with the amount of the A and G bases being equal to the T and C bases respectively. Furthermore, he also demonstrated that the ratio of these amounts was specific and consistent for a given species. He first laid out his vision for determining the role of nucleic acids in 1947, and over the next decade or so, proceeded to probe the finer details of DNA chemistry with the then state-of-the art innovations in techniques such as chromatography and UV spectroscopy. Papers discussed include: Chargaff, Erwin. “On the Nucleoproteins and Nucleic Acids of Microorganisms.” Cold Spring Harbor Symposia on Quantitative Biology 12 (January 1, 1947): 28–34. https://doi.org/10.1101/SQB.1947.012.01.006. Vischer, Ernst, and Erwin Chargaff. “The Separation and Quantitative Estimation of Purines and Pyrimidines in Minute Amounts.” Journal of Biological Chemistry 176 (1948): 703–14. Chargaff, Erwin. “Chemical Specificity of Nucleic Acids and Mechanism of Their Enzymatic Degradation.” Experientia 6, no. 6 (June 15, 1950): 201–9. Joining us to illuminate the role of Chargaff and his experiments in the history of DNA are: Pnina Abir-Am, Brandeis University Kersten Hall, University of Leeds Hans-Jörg Rheinberger, Max Planck Institute for the History of Science View more at https://www.chstm.org/video/144 Recorded August 9, 2023.