Luis Federico Leloir, 6 September 1906 - 3 December 1987

Abstract With the death of Luis Federico Leloir, in December 1987, the world lost one of the greatest biochemists of our time, for Leloir’s pioneering work opened up a new chapter in biochemistry. He discovered a novel class of biological compounds, hybrids of nucleotides and sugars, through which the synthesis of oligo- and polysaccharides is channelled in all living things. This includes glycogen and starch which, together with fats, are the main energy stores of life. Perhaps the greatest impact of Leloir’s work was the recognition that catabolic and anabolic processes do not as a rule proceed via the same reversible pathways but along separate routes. Thus the synthesis of the amylose chains of glycogen was believed to occur by reversal of the reaction catalysed by phosphorylase; i.e. (amylose)n + orthophosphate = n glucose-1-phosphate, but Leloir showed that, given the relatively high concentration of inorganic phosphate in the cell, phosphorylase function essentially as a degradative enzyme and that a separate enzyme and a different substrate are involved in amylose synthesis.