[Trace elements as activation factors of enzymes: characteristic enzymes and their activation mechanisms].
We here describe activation mechanisms of three characteristic metalloenzymes by metals. The copper-containing amine oxidase contains a topaquinone residue at the active site. The inactive precursor form of the enzyme, which contains a tyrosine residue at the position corresponding to topaquinone of the matured protein, was isolated and converted to the matured form by incubation with cupric ions through self-processing of the protein. The selenocysteine residue of selenium-containing formate dehydrogenase is synthesized cotranslationally through a process directed by a UGA codon that normally functions as a stop codon. We describe the mechanism of recognition of UGA and specific incorporation of selenium into the protein. Vanadium-containing haloperoxidases afford stable apo forms lacking vanadium. Reconstitution of holo forms by vanadium ions are also described.
Esaki
N
N
Institute for Chemical Research, Kyoto University.
Soda
K
K
D006631:Amine Oxidase (Copper-Containing); D000818:Animals; D004295:Dihydroxyphenylalanine / Q000031:analogs & derivatives / Q000378:metabolism; D005560:Formate Dehydrogenases / Q000378:metabolism; D006801:Humans; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000378:metabolism; D014131:Trace Elements / Q000502:physiology*
D014131:Trace Elements; D004295:Dihydroxyphenylalanine; C067626:6-hydroxydopa quinone; D005560:Formate Dehydrogenases; D006631:Amine Oxidase (Copper-Containing); D000587:Oxidoreductases Acting on CH-NH Group Donors