Akio Isomoto

Dependence of EPR Transition Probability on Magnetic Field

Bleanys theory of the g -value dependence of EPR transition probability is extended to a general case of rhombic ligand field by assuming that the system has a fictitious spin of 1/2. Given three principal g -values and a line shape function, changes in EPR spectra of polycrystalline aggregates with static magnetic field are calculated and a general equation of spectral curve are obtained. In the limiting case of a zero line width, the equation is reduced to an elliptic integral. This approach is applied to the simulation of the EPR spectra of normal and abnormal haemoglobins and pyrocatechase, and the theoretically and experimentally obtained spectra exhibit a good fit.

Color analysis method for estimating the oxygen saturation of hemoglobin using an image-input and processing system

A color analysis method which enables both qualitative and quantitative analyses of an objects color was developed. The method uses a color image-input and processing system composed of a 3-tube video camera and a digital image analyzer, which quantizes a color image into values of red, green, and blue brightness, then processes these values. We introduced a spectrophotometric principle by the Beer-Lambert law, and were able to establish a color model to analyze an objects color. In the coordinate space based on our color model, the hue of the objects color is represented by the direction from the origin, and the density by the distance from the origin. This new method was used to analyze the colors of hemoglobin solutions at various oxygen saturations and concentrations. The results agreed with the known conditions, indicating the validity of the model and its usefulness for quantitative as well as qualitative analyses of color.

Circular dichroism of human hemoglobin-haptoglobin complexes

Abstract The circular dichroism spectra (600 – 240 mμ) of four derivatives of human hemoglobin-haptoglobin complexes have been measured. The circular dichroism spectra of the human hemoglobin-haptoglobin complex are different from those of hemoglobin A and its subunits in the Soret region and in the 310 – 240 mμ region. The spectral difference in the Soret region between the hemoglobin-haptoglobin complex and hemoglobin A and its subunits indicates the presence of difference in the heme environment or a difference in the tightness of the heme attachment, or both, between the hemoglobin-haptoglobin complex and hemoglobin A and its subunits.

A dynamic dialysis method for studying protein-ligand binding using chromatographic theory

A new dynamic dialysis method has been developed for studying protein-ligand binding phenomena. The method depends on analysis of the elution pattern of ligand in a single dialyzing process where the ligand concentration in the sample compartment changes greatly with time. The dialyzer is composed of a long, narrow chamber (the sample compartment) between two sheets of semipermeable membrane and two outside chambers (the sink compartment) connected as a single path. Eluting buffer flows in the sink compartment to exchange the ligand with the solution in the sample compartment. Therefore, the ligand concentration gradient in the sink compartment is in the longitudinal direction. The mathematical expressions to analyze the experimental data were derived from a modified theory of chromatography. Examination of the binding of sulfanilamide to bovine serum albumin using this method shows that these equations are valid for use in studying protein-ligand binding.

Color Analysis Method for Studying Oxygen Transport in Hemoglobin Solutions Using an Image-Input and -Processing System

A method for quantitative analysis of hemoglobin color to estimate the oxygen saturation was developed. The method uses an image-input and -processing system composed of a 3-tube video camera and a digital image analyzer. Using the system connected to a microscope, facilitated diffusion of oxygen in hemoglobin solutions was observed and analyzed in a position-sensitive way. The results confirmed its applicability to this study and gave information about the diffusion mechanism expressed by the empirical formula J = kY, where J is the flux of oxygen, Y is the oxygen saturation of hemoglobin, and k is a constant.