Accession Number : ADA268228


Title :   Sodium Ions Affect the pH behavior of the Soluble Hydrogenase of Alcaligenes Eutrophus H16


Descriptive Note : Technical rept. Jan-Oct 91,


Corporate Author : NAVAL MEDICAL RESEARCH INST BETHESDA MD


Personal Author(s) : Tyree, B ; Harabin, A L ; DeJesus, J R ; Kumaroo, K K


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a268228.pdf


Report Date : Jan 1993


Pagination or Media Count : 20


Abstract : Hydrogenase activity of the soluble hydrogenase from Alcaligenes eutrophus H16 was inhibited by monovalent cations in the order Na+Li+K+NH4+Cs+. Hydrogenase activity was also slightly inhibited by monovalent anions. The Na(+) -induced inhibition was not altered with varying NAD+ or H2 concentrations, suggesting that Na+ ions do not interfere with substrate binding. The inhibition was lowered when the H+ concentration was increased over a range of pH 8.5 to 7.0. Examination of the pH-velocity curve shows that NaC1 lowers and shifts the pH optimum in the acidic direction. These data suggest that Na+ ions bind to the enzyme, perhaps displacing protons.


Descriptors :   *INHIBITION , *HYDROGENATION , IONS , CATIONS , ENZYMES , SODIUM , SUBSTRATES , PH FACTOR , ANIONS , PROTONS , METABOLISM , HYDROGEN , INHIBITORS


Subject Categories : Biochemistry


Distribution Statement : APPROVED FOR PUBLIC RELEASE