Snell, Esmond

Snell, Esmond E., and Broym, Gene M., Panthethine and Related... 

Snell, E. E., and Esmond, E., The microbiological assay of amino acids. Advances in Protein Chem. 2, 85-116 (1945). 

Avidin was first isolated from chicken egg white by Esmond Emerson Snell (1914-2003). This tetrameric protein contains four identical subunits (homotetramer) each of which can bind to biotin (Vitamin B7, vitamin H) with a high degree of affinity and specificity. When these two molecules are in the same solution, they will bind with such high affinity that the binding is essentially irreversible. No matter how many times you wash them, they will not let go of each other. 

Esmond E. Snell, Derrol Pennington, and Roger J. Williams, J. Biol. Chem., 133, 559565 (1940). 

In 1944, Esmond Snell reported the nonenzymatic conversion of pyridoxal into pyridoxamine (Box 14-C) by heating with glutamate. He recognized that this was also transamination and proposed that pyridoxal might be a part of a coenzyme needed for aminotransferases and that these enzymes might act via two halfreactions that interconverted pyridoxal and pyridoxamine (Eq. 14-25). The hypothesis was soon verified and the coenzyme was identified as pyridoxal 5 -phos-phate or pyridoxamine 5 -phosphate (Fig. 14-5).144/145... 

Schiff Base Intermediates in Enzyme Catalysis Esmond E. Snell and Samuel J. DiMari... 

Early work by Esmond Snell on the enzymes that employ pyridoxal phosphate included experiments in which free pyridoxal was heated with amino acids like glutamate. Snell found that the (-amino group of glutamate was transferred to pyridoxal, generating pyridoxamine. Why was this an important clue to the function of pyridoxal as a cofactor ... 

Analogously to the artificial diet for humans, microbiologists attempted to prepare a purified medium for microorganisms comprising all the necessary nutrients in chemically pure form. In 1939, Esmond Snell observed that, when riboflavin was added to the medium for Lactobacillus casei, in which the peptone was treated with alkali in advance to destroy the inherent riboflavin, no growth was observed. This indicated that some nutritional factors were... 

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