Por favor, use este identificador para citar o enlazar a este item:
http://hdl.handle.net/10261/76425
COMPARTIR / EXPORTAR:
SHARE CORE BASE | |
Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL | DATACITE | |
Título: | Pneumococcal phosphorylcholine esterase, Pce, contains a zinc binuclear center that is essential for substrate binding and catalysis |
Autor: | Lagartera, Laura CSIC ORCID; González, Ana CSIC; Hermoso, Juan A. CSIC ORCID; Sáiz, José Luis CSIC; García, Pedro CSIC ORCID ; García, José Luis CSIC ORCID ; Menéndez, Margarita CSIC ORCID | Palabras clave: | zinc-metallo hydrolases Choline-binding proteins DSC Catalytic activity pneumococcal Pce Binuclear zinc-center |
Fecha de publicación: | 2005 | Editor: | Wiley-Blackwell | Citación: | Protein Science 14(12): 3013-3024 (2005) | Resumen: | The phosphorylcholine esterase from Streptococcus pneumoniae, Pce, catalyzes the hydrolysis of phosphorylcholine residues from teichoic and lipoteichoic acids attached to the bacterial envelope and comprises a globular N-terminal catalytic module containing a zinc binuclear center and an elongated C-terminal choline-binding module. The dependence of Pce activity on the metal/enzyme stoichiometry shows that the two equivalents of zinc are essential for the catalysis, and stabilize the catalytic module through a complex metal-ligand coordination network. The pH dependence of Pce activity toward the alternative substrate p-nitrophenylphosphorylcholine (NPPC) shows that kcat and kcat/Km depend on the protonation state of two protein residues that can be tentatively assigned to the ionization of the metal-bound water (hydrogen bonded to D89) and to H228. Maximum activity requires deprotonation of both groups, although the catalytic efficiency is optimum for the single deprotonated form. The drastic reduction of activity in the H90A mutant, which still binds two Zn2+ ions at neutral pH, indicates that Pce activity also depends on the geometry of the metallic cluster. The denaturation heat capacity profile of Pce exhibits two peaks with Tm values of 39.6°C (choline-binding module) and 60.8°C (catalytic module). The H90A mutation reduces the high-temperature peak by about 10°C. Pce is inhibited in the presence of 1 mM zinc, but this inhibition depends on pH, buffer, and substrate species. A reaction mechanism is proposed on the basis of kinetic data, the structural model of the Pce:NPPC complex, and the currently accepted mechanism for other Zn-metallophosphoesterases | Descripción: | 11 páginas, 6 figuras. 6 tablas -- PAGS nros. 3013-3024 | Versión del editor: | http://dx.doi.org/10.1110/ps.051575005 | URI: | http://hdl.handle.net/10261/76425 | DOI: | 10.1110/ps.051575005 | ISSN: | 0961-8368 | E-ISSN: | 1469-896X |
Aparece en las colecciones: | (CIB) Artículos |
Ficheros en este ítem:
Fichero | Descripción | Tamaño | Formato | |
---|---|---|---|---|
accesoRestringido.pdf | 15,38 kB | Adobe PDF | Visualizar/Abrir |
CORE Recommender
PubMed Central
Citations
4
checked on 26-mar-2024
SCOPUSTM
Citations
9
checked on 28-mar-2024
WEB OF SCIENCETM
Citations
8
checked on 26-feb-2024
Page view(s)
290
checked on 28-mar-2024
Download(s)
86
checked on 28-mar-2024
Google ScholarTM
Check
Altmetric
Altmetric
Artículos relacionados:
NOTA: Los ítems de Digital.CSIC están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.