Abstract
The oxoglutarate carrier (OGC) purified from bovine heart mitochondria was treated, both in its active and in its SDS-denatured state, with the fluorescent N-(1-pyrenyl)maleimide and other SH reagents before and after reduction with dithioerythritol or β-mercaptoethanol. The number of SH groups per OGC polypeptide chain was found to be about 1 for the oxidized carrier and 3 for the reduced carrier. The bovine oxoglutarate carrier contains three cysteines: Cys-184, Cys-221 and Cys-224. Sequencing of BrCN cleavage products of oxoglutarate carrier showed that N-(1-pyrenyl)maleimide binds to only Cys-184 of the oxidized protein and also to Cys-221 and Cys-224 after reduction of the protein. These results show the presence of a disulfide bridge between the latter two cysteines of the purified carrier. The oxidized and the reduced forms of the oxoglutarate carrier exhibited different V max but virtually the same K m values for oxoglutarate.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.