Corroborative cobalt and zinc model compounds of alpha-amino-beta-carboxymuconic-epsilon-semialdehyde decarboxylase (ACMSD).
Dalton Trans
; (1): 51-62, 2009 Jan 07.
Article
en En
| MEDLINE
| ID: mdl-19081971
ABSTRACT
We have synthesised and characterised a series of new Co(II) complexes (1-4, 6, 7) and one new Zn(II) complex (5) employing N(3)- and N(3)O-donor ligands [biap N,N-bis(2-ethyl-5-methyl-imidazol-4-ylmethyl)amino-propane, KBPZG potassium N,N-bis(3,5-dimethylpyrazolylmethyl) glycinate, KBPZA potassium N,N-bis(3,5-dimethylpyrazolylmethyl) alaninate, KB(i)PrPZG potassium N,N-bis(3,5-di-iso-propylpyrazolylmethyl) glycinate, and KB((t)BuM)PZG potassium N,N-bis(3-methyl-5-tert-butyl-pyrazolylmethyl)glycinate] as structural models of the metalloenzyme alpha-amino-beta-carboxymuconic-epsilon-semialdehyde decarboxylase (ACMSD). These complexes were characterised by several techniques including X-ray crystallographic analysis, X-band EPR, and mass spectrometry (ESI-MS). The crystal structures of 1, 2, 6,7 revealed that they exist as mononuclear Co(II) complexes with trigonal-bipyramidal geometry in the solid state. Compounds 3 and 5 form infinite polymeric chains of Co(II) or Zn(II) complexes, respectively, linked by the pendant carboxylate arms of the BPZG(-) ligand. By comparing the degree of distortion in the penta-coordinate complexes, defined by the Addison-parameter tau, with the value determined for the five-coordinate centres found in the active site of ACMSD, it could be seen that complexes 5 and 7 are very good matches for the geometry of the zinc(II) centre in monomer A of the native enzyme. All complexes could be seen as model compounds for the active site of the enzyme ACMSD, where the Co(II) complexes reflected the structural flexibility found in case of two histidine (His177 and His228) residues found in the active site of the enzyme.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Zinc
/
Carboxiliasas
/
Modelos Moleculares
/
Cobalto
Idioma:
En
Revista:
Dalton Trans
Asunto de la revista:
QUIMICA
Año:
2009
Tipo del documento:
Article
País de afiliación:
Estados Unidos