[Conformation analysis of a mixed hemoglobin-glutathione disulfide]

Abstract

Theoretical conformational analysis was carried out for a mixed disulfide of hemoglobin with glutathione. The conformational mobility of the beta-subunit C-terminal fragment in methemoglobin and deoxyhemoglobin either with free or glutathione-blocked reactive SH-groups was examined. The most stable conformations of the mixed disulfide were delineated. Its spatial structure was shown to be dependent on the hemoglobin state prior to the S-S bond formation: a disulfide made with deoxyhemoglobin had more closely interwoven hemoglobin and glutathione chains than the methemoglobin-derived disulfide. However, in both cases disulfide formation brought about the alterations in the spatial structure of hemoglobin as well as glutathione. The changes in the hemoglobin biochemical properties accompanying the association with glutathione were rationalized in the frames of the mixed disulfide structural analysis.