Abstract
Glutamine synthetase (GS) from bovine retina was purified to apparent homogeneity by ammonium sulfate fractionation followed by Sephacryl S-200, hydroxylapatite, and Sephadex G-150 chromatography. The purified enzyme showed a single band on polyacrylamide gel electrophoresis. Based on the purification data, retinal GS was shown to be approximately 2% of the total soluble retinal protein. By gel filtration, sedimentation velocity centrifugation, and gel electrophoresis, it was shown that the enzyme has a subunit molecular weight of 45000 daltons and a native molecular weight of 360000 daltons, which is consistent with an octameric structure. Throughout the various stages of purification, it was found that GS and glutamyl transferase (GT) activities were maintained at a constant ratio. Thus, the GS and GT reactions are catalyzed by the same enzyme. Immunodiffusion of antiretinal GS antibodies gave a single line of precipitation with both crude retinal and brain enzymes as well as purified enzyme preparations. Precipitation lines of retinal and brain enzymes completely fused with each other without any spur formation. The immunochemical titration of brain enzyme activity with antiretinal GS antibodies also revealed an immunological homology between retinal and brain enzymes.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: 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.
