Abstract
5-Aminolevulinate synthase from yeast mitochondria has been purified to homogeneity for the first time. By using affinity chromatography on agarose-hexane-CoA, gel filtration and DEAE-Sepharose chromatography, the enzyme was purified about 7000-fold with an overall yield of 40%. The specific activity of the final preparation was 39000 nmol of 5-aminolevulinate h-1 mg-1 of protein at 30 degrees C. As judged by gel filtration, polyacrylamide gradient gel and sodium dodecyl sulfate/polyacrylamide gel electrophoresis, the enzyme appeared to be composed of two identical subunits of a relative molecular mass of 53000. Electrophoresis of sodium-dodecyl-sulfate-solubilized yeast homogenate followed by immune replica analysis showed that the value of 53000 is the Mr of a non-degraded form. The purified enzyme had an isoelectric point of 5.3 and a pH optimum of 7.4. Pyridoxal 5'-phosphate has been shown to be an essential cofactor. The enzyme activity was sensitive to thiol blocking reagents. Hemin, but not heme, inhibited the activity of the purified enzyme.
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.
