29] Effects of wavelength on fitting Adair constants for binding of oxygen to human hemoglobin

Abstract

Publisher Summary This chapter focuses on the effects of wavelength on fitting Adair constants for binding of oxygen (O 2 ) to human hemoglobin (Hb). This chapter presents enzymatic depletion of O 2 in the solution as an alternative to equilibration with a gas phase and the use of myoglobin as an O 2 sensor to eliminate stirring altogether. However, a more recent study in the same wavelength region concluded that the apparent binding constants were indeed wavelength dependent. In using an oxygen electrode, a procedure to smooth the data using exponential splines has been developed that is appropriate when the deoxygenation process, as carried out enzymatically, can be regarded as piecewise exponential. Such smoothed data can then be incorporated into deconvolution procedures to recover the distortions from the electrode time constant. Higher precision spectrophotometers with increasingly sophisticated computerized data acquisition and noise reduction techniques may allow the E values as well as the Adair constants to be better defined. Work at high concentrations will require special cells for multiple path lengths with O 2 electrode or optical sensing of O 2 concentration.