Models for the Active Center of Pterin-Containing Molybdenum Enzymes: Crystal structure of a molybdenum complex with sulfur and pterin ligands
| Autor: | Helmut W. Schmalle, Markus R. Baumgartner, Max Viscontini, Berthold Fischer |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
Stereochemistry
Ligand Organic Chemistry chemistry.chemical_element Protonation Crystal structure Biochemistry Catalysis Inorganic Chemistry Active center Metal chemistry.chemical_compound Crystallography chemistry Molybdenum visual_art Drug Discovery visual_art.visual_art_medium Physical and Theoretical Chemistry Pterin Monoclinic crystal system |
| Zdroj: | Helvetica Chimica Acta. 80:103-110 |
| ISSN: | 1522-2675 0018-019X |
| DOI: | 10.1002/hlca.19970800110 |
| Popis: | The first crystal structure of a molybdenum complex 9 with a hydrogenated pterin and a sulfur ligand contributes to the discussion about the active center of molybdenum and tungsten enzymes containing a molybdopterin cofactor. Complex 9 was synthesized through a redox reaction of [MoVIO2 (LN-S2)] (8; LN-S2 = pyridine-2, 6-bis(methanethiolato)) with 5, 6, 7, 8-tetrahydropterin (7). 2 HCl (H4Ptr.2 HCl). The complex crystallizes, with a non-coordinating Cl-atom acting as a counterion, in the monoclinic space group C2/c (No. 15) with cell dimensions a = 22.900(5), b = 10.716(2), c = 17.551(4) A, β = 120.36(3)°, and Z = 8. We interpret 9 as [MoIVO(LN-S2)(H+-q-H2Ptr)]Cl (q = quinonoid; H2Ptr = dihydropterin), i.e., a MoIV monooxo center coordinated by a pyridine-2, 6-bis(methanethiolato) ligand and a protonated dihydropterin. The spectroscopic properties of this new complex are comparable to those of other crystalline molybdenum complexes of hydrogenated pterins without additional S-coordination. The slightly H2O-soluble complex 9 reacts with the natural enzyme substrate DMSO very slowly, possibly due to the lack of easily dissociable ligands at the metal center. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text