title: On the nature of the activating enzyme of the inactive form of delta-aminolevulinate synthetase in Rhodopseudomonas spheroides.
abstract: The activating enzyme of the inactive form of Fraction I of delta-aminolevulinate (ALA) synthetase [EC 2.3.1.37] in Rhodopseudomonas (R.) spheroides was purified about 1,000-fold from an extract of R. spheroides cells grown anaerobically in the light. The purification of the activating enzyme was achieved by fractionating the 100,000 X g supernatant fraction of the crude extract with ammonium sulfate and acetone, followed by Sephadex G-200 chromatography, pyridoxamine phosphate-Sepharose 4B chromatography, and preparative gel electrophoresis. The final preparation of the activating enzyme still contained a minor contaminant (less than 20%) as judged by disc gel electrophoresis. The activating enzyme exhibited cystathionase [EC 4.4.1.1] activity throughout the purification. These two enzyme activities were not separated at all during any step of the purification. An apparently homogeneous preparation of cystathionase [EC 4.4.1.8] purified from rat liver also exhibited activating activity in the presence of L-cystine. It was concluded that the activating enzyme is a cystathionase.
mesh_terms: D000624:5-Aminolevulinate Synthetase / Q000302:isolation & purification / Q000378:metabolism*; D000818:Animals; D003542:Cystathionine gamma-Lyase / Q000302:isolation & purification / Q000378:metabolism; D003553:Cystine / Q000494:pharmacology; D004789:Enzyme Activation; D008099:Liver / Q000201:enzymology; D051381:Rats; D012242:Rhodobacter sphaeroides / Q000201:enzymology*
chemical_list: D003553:Cystine; D000624:5-Aminolevulinate Synthetase; D003542:Cystathionine gamma-Lyase