yed the entire experiment. Returning the next morning, Kornberg noticed one vile in the centrifuge. The remains had separated, and he collected the solid material. This fraction had the bulk of the enzyme activity and was several-fold purer than the best of all previous preparations. This step (without the cylinder breakage) became part of the published procedure on enzyme purification. During his time spent with Severo Ochoa at New York University School of Medicine in 1946, and time spent with Carl and Gerty Cori at the Washington University School of Medicine in St. Louis in 1947, Kornberg refined his knowledge of enzyme production, as well as isolation and purification techniques. C. Specific Information on a Specific Contribution In 1948, Kornberg returned to the National Institute of Health as chief of the enzyme and metabolism section and established his own laboratory. He continued his work in the purification of enzymes. It was four years later (he calls these years his golden working years) that Kornberg had purified an enzyme from potatoes. He called the enzyme nucleotide pyrophosphatase and discovered how to cleave the complex coenzymes gently enough to leave their component halves intact. He was able to advance his knowledge of the location of one of three phosphate groups of NADP (nicotinamide adenine dinucleotide phosphate). Cleaving NAD (nicotinamide adenine dinucleotide) gave him the key to the discovery of the wondrous enzyme that makes NAD. With the discovery of an enzyme goes the privilege and burden of naming it. Kornberg named the enzyme NAD synthetase. This discovery gave him instant recognition among biochemists and set him on a career devoted to the enzymes that assemble DNA, genes, and chromosomes. His pursuit of this particular enzyme would lead him to the synthesis of coenzymes, to the origin of inorganic pyrophosphate, and eventually to the replication of DNA. During his time spent at the National Institut...
