Making the Gradient

By Karen Hopkin Making the Gradient Ron Kaback didn’t believe that electrochemical gradients could power the transport of sugars and amino acids across cell membranes—until he proved that they do. H. RONALD KABACK Professor of Physiology University of California, Los Angeles F1000 Faculty Member: Neuronal Signaling Mechanisms Photo © 2011 Jim Cornfield Ron Kaback got hooked on membrane transport as a medical student at the Albert Einstei

Written byKaren Hopkin
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Ron Kaback got hooked on membrane transport as a medical student at the Albert Einstein College of Medicine in the late 1950s. “I went to all the biochemistry seminars, and one of the first ones I heard was given by Werner Maas, a geneticist at NYU. He had discovered the first mutants that become antibiotic resistant by losing the ability to take up the antibiotic,” he says. These mutant strains of E. coli proliferated normally in the presence of certain growth-inhibitory amino acids. “And the way they became resistant to these amino acids is they lost the ability to transport them.” The experiments Maas described reminded Kaback of a talk he’d heard as an undergraduate at Haverford College, in which Arthur Kornberg described work done by his then postdoc Paul Berg on transfer RNA—the RNAs that move amino acids to growing proteins. “So I’m sitting there listening and a light ...

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