Gordon Henry Dixon. 25 March 1930—24 July 2016

Abstract

Gordon H. Dixon was a highly influential scientist who excelled in all the stages of his career and in each laboratory of every institution at which he was a member. Gordon began his graduate career at the University of Cambridge and completed his studies at the University of Toronto on the subject of transpeptidation reactions in biological systems. At an early stage of his career, he developed the technique of starch gel electrophoresis with Oliver Smithies and made important discoveries on the structure of human haptoglobins. Subsequently, Gordon contributed to the determination of the structure and active sites and mechanisms of action of trypsin and chymotrypsin and made seminal discoveries related to understanding the structure of the protein hormone insulin. However, he is best known for his later studies on the regulation of protamine genes and chromatin transitions in spermatogenesis. He is often considered to be the father of the protamine molecular biology underlying this gene system and his research is continually cited to this day. Gordon contributed to the identification and sequencing of the protamine genes, the discovery that methionine was required for initiation of protamine synthesis, understanding the roles of histone hyperacetylation and protamine phosphorylation, and the generation of the highly compact nucleoprotamine structure present in sperm, primarily using trout as a model system. Gordon is fondly remembered as a brilliant and very generous scientist by all his mentees, representing all levels from undergraduates to PhD and postdoctoral fellows, who provided a scientifically stimulating atmosphere in which they could develop their careers. From a more personal perspective, he also had a fun side and was devoted to his family. Gordon was a person who, owing to his legacy of great science and his fundamental humanity, still lives in the memory of many people.