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dc.contributor.author
Sanchez, Julieta Maria
dc.contributor.author
Ciklic, Iván Francisco
dc.contributor.author
Perillo, Maria Angelica
dc.date.available
2018-09-05T16:08:13Z
dc.date.issued
2005-12-01
dc.identifier.citation
Sanchez, Julieta Maria; Ciklic, Iván Francisco; Perillo, Maria Angelica; Effect of partitioning equilibria on the activity of β-galactosidase in heterogeneous media; Elsevier Science; Biophysical Chemistry; 118; 2-3; 1-12-2005; 69-77
dc.identifier.issn
0301-4622
dc.identifier.uri
http://hdl.handle.net/11336/58383
dc.description.abstract
We had demonstrated that membrane adsorption or penetration differentially modulated β-Galactosidase (β-Gal) activity against soluble substrates (Coll. and Surf., 24, 21, 2002). In a heterogeneous media, not only the enzyme but also the rest of the chemical species taking part in a chemical reaction would eventually interact with the available surfaces. The aim of the present work was to investigate if, in addition to changes in the intrinsic mechanism of the reaction at the lipid-water interface, the kinetics of enzyme-catalyzed reactions could be significantly affected by the partitioning of the substrate (ortho-nitro-phenyl galactopyranoside (ONPG)), the product (ortho-nitro-phenol (ONP)) and the enzyme (E. coli β-Gal) towards the membrane. Multilamellar vesicles of sPC were used as model membranes. Membrane-water partition coefficients (P m/w) were determined according to the theory and methodology developed previously (J. Neurosci. Meth. 36, 203, 1991). The values of P m/w obtained (P ONPG = 0, P ONP = 50 and P β-Gal = 118) were applied to a two-compartment model, which assumed a free access of the substrate to the enzyme and a nucleophile-like activatory effect exerted, within the membrane compartment, by the lipid-water interface. This model: (i) reproduced the lipid concentration-dependence we had observed previously in V max, (ii) predicted the values of k 4 = 3.54 × 10 7 s - 1 and the extinction coefficient of the aglycone in the membrane phase, 4012 M - 1 cm - 1, with p < 0.0001 and p < 0.02, respectively, as well as for P β-Gal = 117 (which was poor (p = 0.6716) but gave a numerical value within the same order of magnitude that the experimental value) and (iii) emphasized the importance of the more efficient reaction mechanism in the membrane phase compared with that in the aqueous phase (k 4 ≫ k 3).
dc.format
application/pdf
dc.language.iso
eng
dc.publisher
Elsevier Science
dc.rights
info:eu-repo/semantics/restrictedAccess
dc.rights.uri
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.subject
Β-Galactosidase
dc.subject
Enzyme Kinetics
dc.subject
O-Nitrophenyl-Β-D-Galactopyranoside
dc.subject
Partition Coefficient
dc.subject
Phospholipids Vesicles
dc.subject.classification
Otras Ciencias Biológicas
dc.subject.classification
Ciencias Biológicas
dc.subject.classification
CIENCIAS NATURALES Y EXACTAS
dc.title
Effect of partitioning equilibria on the activity of β-galactosidase in heterogeneous media
dc.type
info:eu-repo/semantics/article
dc.type
info:ar-repo/semantics/artículo
dc.type
info:eu-repo/semantics/publishedVersion
dc.date.updated
2018-08-13T17:07:00Z
dc.journal.volume
118
dc.journal.number
2-3
dc.journal.pagination
69-77
dc.journal.pais
Países Bajos
dc.journal.ciudad
Amsterdam
dc.description.fil
Fil: Sanchez, Julieta Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Química; Argentina
dc.description.fil
Fil: Ciklic, Iván Francisco. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Química; Argentina
dc.description.fil
Fil: Perillo, Maria Angelica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Química; Argentina
dc.journal.title
Biophysical Chemistry
dc.relation.alternativeid
info:eu-repo/semantics/altIdentifier/url/https://www.sciencedirect.com/science/article/pii/S0301462205001250
dc.relation.alternativeid
info:eu-repo/semantics/altIdentifier/doi/http://dx.doi.org/10.1016/j.bpc.2005.05.009


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