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- 1962 (Creation)
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Extent: 1 folder
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11 letters between Roy Markham and David Lipkin: breakdown of turnip yellow mosaic virus nucleic acid by ethanol, 'coding', cyclic adenylic acid, TYM virus, Leon Heppel, iodoguanosine, visit to America. Dates RM to DL: 5 Mar, 5 Oct, 15 Oct, 22 Nov and 19 Dec. DL to RM: 19 Feb, 15 May, 18 Sep, 6 Nov, 3 Dec (x2).
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Admin History: In the early 1950s, in collaboration with his longtime colleague Russell Hilmoe, Heppel focused on enzymes that hydrolyzed RNA, particularly spleen phosphodiesterase. The nature of the products formed and the phosphodiester bond hydrolyzed by this enzyme were elucidated by Heppel during a sabbatical period at the Molteno Institute in Cambridge, England (1953) in collaboration with Roy Markham and John D. Smith. Their laboratory had developed cutting-edge methodologies that separated and identified RNA fragments using paper chromatography and paper electrophoresis. These studies demonstrated that the natural configuration of the internucleotide linkage in RNA was 3’-5’ rather than 2’-5’. In collaboration with Paul Whitfield, a graduate student in Markham’s laboratory at that time, Heppel demonstrated that the hydrolysis of RNA by pancreatic RNase occurred through a cyclic oligonucleotide, which was isolated and elegantly characterized.