Abstract
Forward and backward extraction behavior of hemoglobin using a bis(2-ethylhexyl) sulfosuccinate sodium (AOT) reverse micellar system was investigated, and successful extractions of hemoglobin in this system were achieved. Forward extraction of hemoglobin from the feed solution to the reverse micellar organic phase was dependent on the feed conditions such as pH, salt concentration, and initial protein concentration. Optimal pH of the feed solution was found to be 6.0. The forward extraction of hemoglobin decreased with increasing salt concentration, increased with decreasing initial protein concentration. The forward extraction percentage of 3 µM hemoglobin increased with the AOT concentration in the reverse micellar organic phase and reached a plateau of ca. 100 % at an AOT concentration of 100 mM. Almost complete backward extraction from the micellar organic phase was easily obtained by ingeniously controlling the salt concentration in the recovered aqueous phase. Higher order structure of the hemoglobin recovered from the reverse micellar organic phase was examined by circular dichroic measurement, which suggested that the extracted hemoglobin strongly interacted with AOT molecules.
