Irwin G Leder

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Permease studies are generally carried out by incubating cells in growth medium with labeled substrate, collecting the cells on microporous membrane filters, and washing them free from extracellular radioactivity with ice-cold medium. Studies of thiomethylgalactoside, valine, and galactose accumulation indicate that in several strains of Escherichia coli(More)
An octasaccharide with high affinity for antithrombin was isolated after partial deaminative cleavage of heparin with nitrous acid. After conversion of the 2,5-anhydro-D-mannose end group to anhydro[1-3H]mannitol, labeled pentasaccharide was released from the octasaccharide by periodate-alkali treatment. Incubation of the pentasaccharide with a recently(More)
The catalysis, by the enzyme thiaminase, of reversible baseexchange reactions between thiamine and aromatic tertiary amines was first reported by Fujita et al. (1). Related findings with mammalian diphosphopyridine nucleotidases (2) and with methionine activation (3) drew attention to the energy-rich nature of “onium” (4-6) compounds and suggested that the(More)
Previous studies (1, 2) have indicated that gluconate is extensively metabolized in the mammal without, prior conversion to glucose. The int,erpretation of experiments performed with labeled gluconate has rested upon the assumption (3) that gluconate is converted to 6-phosphogluconate in t,he course of its metabolism. The enzyme, gluconokinase, which(More)