Video Experimental Relacionado
Updated: Aug 14, 2026
13:34
Production, Crystallization and Structure Determination of C. difficile PPEP-1 via Microseeding and Zinc-SAD
Published on: December 30, 2016
Estructura cristalina de una fosfatasa ácida púrpura que contiene un sitio activo dinuclear Fe(III) -Zn(II)
N Sträter1, T Klabunde, P Tucker
1Anorganisch-Chemisches Institut, Universität Münster, Germany.
Science (New York, N.Y.)
|June 9, 1995
Resumen
La fosfatasa ácida púrpura de frijol de riñón (KBPAP) es una enzima Fe (III) - Zn (II). Su estructura revela detalles del sitio activo cruciales para la comprensión de los mecanismos de hidrólisis de los ésteres fosfatados.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Biología Estructural Biología estructural.
- Enzimología Enzimología.
Sus antecedentes:
- La fosfatasa ácida púrpura de frijol de riñón (KBPAP) es una metalloenzima Fe (III) - Zn (II).
- Comparte similitudes estructurales y funcionales con las fosfatasas ácidas púrpuras de mamíferos.
Objetivo del estudio:
- Para determinar la estructura tridimensional de alta resolución de KBPAP.
- Para aclarar la arquitectura del sitio activo y la coordinación de iones metálicos.
Principales métodos:
- Se utilizó la cristalografía de rayos X para determinar la estructura del KBPAP homodímero.
- La estructura se resolvió a una resolución de 2,9 angstroms.
Principales resultados:
- Se aclaró la estructura homodimérica de 111 kilodaltones de KBPAP.
- El sitio activo presenta dos iones metálicos (Fe (III) y Zn (II)) puenteados por Asp164.4.
- Residuos específicos de aminoácidos coordinan los iones metálicos, incluidos Tyr167, His325, Asp135, His286, His323, y Asn201.
Conclusiones:
- La estructura del sitio activo determinado apoya los mecanismos propuestos para la hidrólisis de ésteres fosfatados.
- Los hallazgos destacan el papel de un ion hidróxido coordinado Fe (III) en el ataque nucleófilo a los ésteres de fosfato.
Más Videos Relacionados
Videos de Conceptos Relacionados
03:45Formation of Complex Ions
A type of Lewis acid-base chemistry involves the formation of a complex ion (or a coordination complex) comprising a central atom, typically a transition metal cation, surrounded by ions or molecules called ligands. These ligands can be neutral molecules like H2O or NH3, or ions such as CN− or OH−. Often, the ligands act as Lewis bases, donating a pair of electrons to the central atom. These types of Lewis acid-base reactions are examples of a broad subdiscipline called coordination...
02:58Crystal Field Theory - Octahedral Complexes
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
Tetrahedral Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
01:57Gene Families
Gene families consist of groups of genes proposed to have originated from a common ancestor. Typically these arise through events in which a gene or genes are mistakenly duplicated during cell division. Unlike their parent genes (which are subject to selection pressure to maintain function), these gene copies do not need to preserve their sequences and may evolve at a relatively faster rate.
Occasionally these regions can be adapted to take on new roles within the organism, becoming novel genes...
Occasionally these regions can be adapted to take on new roles within the organism, becoming novel genes...
01:43Electron Transport Chain: Complex III and IV
During the electron transport chain, electrons from NADH and FADH2 are first transferred to complexes I and II, respectively. These two complexes then transfer the electrons to ubiquinol, which carries them further to complex III. Complex III passes the electrons across the intermembrane space to Cyt c, which carries them further to complex IV. Complex IV donates electrons to oxygen and reduces it to water. As electrons pass through complexes I, III, and IV, the energy released aids the pumping...
01:26EDTA: Auxiliary Complexing Reagents
EDTA titrations are usually carried out in highly basic conditions, where the fully deprotonated form of EDTA, Y4−, actively complexes with the free metal ions in the solution. Several metal ions precipitate as hydrous oxide (hydroxides, oxides, or oxyhydroxides) under these conditions, lowering the concentration of free metal ions in the solution. For this reason, auxiliary complexing agents or ligands such as ammonia, tartrate, citrate, or triethanolamine are used in EDTA titrations to...