Interactions of nicotinamide adenine dinucleotides with varied states and forms of hemoglobin.

摘要: Abstract Spectrofluorometric techniques were used to quantify NADPH-hemoglobin interactions based on the quenching of NADPH fluorescence upon binding hemoglobin. Fluorometric titrations carried out with hemoglobin in varied states and hemoglobins which beta-chain anion site is altered. At pH 6.5 0.05 M 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid buffer, binds high affinity, Kd = 1.03 microM, deoxy human tetramers. Lower affinity occurs as anion-binding discharged by increasing pH. Moreover, cofactor a 1:1 ratio tetramers, inositol hexaphosphate competitively, decreased whose structural alterations result effects 2,3-diphosphoglycerate. The oxidized (met) an estimated 33.3 microM but has little or no for oxy form. These results indicate that at can be considered fluorescent analog Fluorescence measurements gave indication deoxygenated ferrous ferric myoglobin. Reductive processes within erythrocyte, such reduction met hemoglobin-catalyzed enzymatic reactions, may affected significant reduced both Cofactor-hemoglobin predict shift redox potential red cells become oxygenated, account unexplained oxygen-linked shifts cell metabolism.