Transferrin--interactions of lactoferrin with hydrogen carbonate.

摘要: The interaction of apolactoferrin with hydrogen carbonate (bicarbonate) has been investigated in the pH range 6.5-9.2. In absence bicarbonate loses a single proton pK1a 8.10. This loss is independent synergistic anion. C-site interacts very low affinity (K(-1)C = 3.2 M(-1)). process accompanied by loss, which probably provided protein. can possibly be result shift dissociation constant, pKa, bicarbonate/carbonate acid/base equilibrium, would decrease from pKa 10.35 to pK2a 6.90 bicarbonate-lactoferrin adduct. N-site protein an extremely affinity, excludes presence N-site-synergistic anion adduct neutral physiological media. Contrary serum transferrin, concentration dependent. Between 7.4 and 9 [HCO3-] about 20 mM, transferrin-bicarbonate always 30%, whereas that apolactoferrin-synergistic varies 25% at 7.5 90% 9. implies that, despite for two orders magnitude lower than lactoferrin better explained possible media, transferrin only bicarbonate.