Abstract
The first protein crystal from which single crystal X-ray diffraction spectra were obtained was a large crystal of the proteolytic enzyme, pepsin. The experiments began, as many protein researches begin, in the laboratory of Arne Tiselius at Uppsala. John Philpot was visiting there for a period in 1934 to work with Tiselius on methods for purifying proteins: the protein he chose to operate on was pepsin. Of this he grew very large crystals—2 mm across—by accident, through leaving his preparation in the refrigerator while he was away on a skiing expedition. He showed the growing crystals to Glyn Millikan, then visiting Uppsala from Cambridge, and Millikan, knowing of Bernal’s great interest in all kinds of crystals and also in biological problems, asked for, and was given, a supply to take back to Bernal in Cambridge. He carried the test-tube containing the crystals as they were, growing in their mother liquor. This enabled Bernal to observe that a single crystal shrank and lost birefringence and order on removal from its mother liquor; he therefore tried taking X-ray photographs from crystals still surrounded by their liquid of crystallization.
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Schedule a callMore From: Philosophical Transactions of the Royal Society of London. B, Biological Sciences
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