Abstract
PROF. SZENT-GYÖRGYI, the well-known Hungarian biochemist and Nobel prize-winner, has recently visited Moscow at the invitation of the Soviet Government. On May 17, he lectured to the Physiological Society at the University of Moscow on his new work on the chemical composition of striated muscle (Acta Physiol. Shan., 9, Suppl. 25; 1945). From muscle material Szent-Györgyi has succeeded in preparing myosin in a crystalline form, and a new protein, isolated by his collaborator, F. B. Straub, called actin. Both myosin and actin have striking properties. Myosin is completely discharged by minimal quantities of potassium. Actin can exist in both globular and fibrous forms, and in the cycle of contraction both forms are involved. The contractile system consists of a combination of these two proteins: actomyosin. In relaxed muscle actomyosin is dissociated into actin and myosin. Actomyosin passes into the contracted form in the presence of potassium, magnesium and adenosin triphosphate. Szent-Györgyi has demonstrated the contractile properties of this system in vitro, and his work provides a mechanical picture which is consistent with all the phenomena of muscle contraction. It is only necessary to assume that in striated muscle there are double rods of actin and myosin, to account for the contraction of living muscle. If the molecules of myosin are spirally arranged around a chain of actin molecules, then contraction, when myosin is discharged by ions, will result in a sudden decrease in the pitch of the spiral. This theory is consistent with microscopic evidence. The familiar cross-striation can be explained by the optical properties of the spiral: for, by rotating muscle fibre under the microscope, Szent-Györgyi has observed the apparent travelling of the spiral along the length of the muscle. This work was done by Szent-Györgyi in Szeged between 1939 and 1944. When the Germans occupied Hungary in 1944, Szent-Györgyi had to go into hiding, and he took a lead in anti-Fascist activities and preparations for the liberation of Hungary. In February 1945 he was liberated by the Red Army. He has now transferred his laboratory to Budapest, and he has accepted chairmanship of the Hungarian Board of Education. Outside his field of research, Szent-Györgyi's main interests are the re-education of his nation for peace, and the re-establishment of international scientific relations.
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Prof. Szent-Györgyi. Nature 155, 750 (1945). https://doi.org/10.1038/155750a0
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DOI: https://doi.org/10.1038/155750a0