Histidine metabolism in liver

• Main Author: Knudson, Alfred G.
• Format: Others
• Published: 1956
• Online Access: https://thesis.library.caltech.edu/1111/1/Knudson%2Cjr_ag_1956.pdf; Knudson, Alfred G. (1956) Histidine metabolism in liver. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/SHM8-FB96. https://resolver.caltech.edu/CaltechETD:etd-03252004-145831 <https://resolver.caltech.edu/CaltechETD:etd-03252004-145831>

This is the report of an investigation of histidine metabolism in mammalian liver. Formiminoglutamic acid, reported to be the end-product of histidine metabolism in vitro, has been found to be degraded enzymatically to glutamic acid by a rat liver extract. Homogenates of spleen, kidney, and heart do not have such activity. A product of the metabolism of the formimino group is carbon dioxide. The effects of time, enzyme concentration, substrate concentration, temperature, and pH on the reaction are reported. Sulfhydryl groups are essential for activity. Inorganic phosphate is stimulatory, and arsenolysis occurs. On the basis of these findings and pertinent published information a scheme for the degradation of histidine to glutamic acid is proposed.