Translations:Insulin/75/en

Hans E. Weber discovered preproinsulin while working as a research fellow at the University of California Los Angeles in 1974. In 1973–1974, Weber learned the techniques of how to isolate, purify, and translate messenger RNA. To further investigate insulin, he obtained pancreatic tissues from a slaughterhouse in Los Angeles and then later from animal stock at UCLA. He isolated and purified total messenger RNA from pancreatic islet cells which was then translated in oocytes from Xenopus laevis and precipitated using anti-insulin antibodies. When total translated protein was run on an SDS-polyacrylamide gel electrophoresis and sucrose gradient, peaks corresponding to insulin and proinsulin were isolated. However, to the surprise of Weber a third peak was isolated corresponding to a molecule larger than proinsulin. After reproducing the experiment several times, he consistently noted this large peak prior to proinsulin that he determined must be a larger precursor molecule upstream of proinsulin. In May 1975, at the American Diabetes Association meeting in New York, Weber gave an oral presentation of his work where he was the first to name this precursor molecule "preproinsulin". Following this oral presentation, Weber was invited to dinner to discuss his paper and findings by Donald Steiner, a researcher who contributed to the characterization of proinsulin. A year later in April 1976, this molecule was further characterized and sequenced by Steiner, referencing the work and discovery of Hans Weber. Preproinsulin became an important molecule to study the process of transcription and translation.