First aminoacetone chelate: [Co(tren){NH2CH2C(O)CH3}]3+-a substrate binding and activation model for zinc(II)-dependent 5-aminolaevulinic acid dehydratase.
The complex p-[Co(tren){NH(2)CH(2)C(O)CH(3)}](ClO(4))(3).H(2)O was produced stereoselectively from [Co(tren)(O(3)SCF(3))(2)]O(3)SCF(3) () and 2-(aminomethyl)-2-methyl-1,3-dioxolane. The structure of was determined by X-ray crystallography. The complex is the first aminoacetone chelate to be reported and the first structurally characterized example of a non-conjugated ketone moiety coordinated to cobalt(iii). The robust complex was stable to aquation in strong acid and behaved as an acid with pK(a) = 4.99(1) indicative of a strong activation of the aminoacetone ligand towards deprotonation. The complex constitutes a structural model for a proposed substrate binding mode relevant for substrate activation of the zinc(ii)-dependent enzyme 5-aminolaevulinic acid dehydratase.
Gumm
Andreas
A
Department of Chemistry, University of Copenhagen, DK-2100, Copenhagen Ø, Denmark.
Hammershøi
Anders
A
Kofod-Hansen
Mikael
M
Mønsted
Ole
O
Osholm Sørensen
Henning
H
D000096:Acetone / Q000031:analogs & derivatives*; D001665:Binding Sites; D002614:Chelating Agents / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004789:Enzyme Activation; D008024:Ligands; D008954:Models, Biological; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D000623:Porphobilinogen Synthase / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry*
C525247:(tris(2-aminoethyl)amine)(aminoacetone)cobalt(III); D002614:Chelating Agents; D008024:Ligands; D009942:Organometallic Compounds; D000096:Acetone; D000623:Porphobilinogen Synthase; D015032:Zinc; C006495:aminoacetone