alpha-Chymotrypsin superactivity in quaternary ammonium salt solution: kinetic and computational studies
De Matteis, L. ; Di Renzo, F. ; Germani, R. ; Goracci, L. ; Spreti, N. ; Tiecco, M.
Resumen: As previously reported, quaternary ammonium salts with bulky hydrophobic portions provoke a superactivation of alpha-chymotrypsin in aqueous solution: this is the case of the surfactant cetyltributylammonium bromide (CTBABr) and the corresponding salt tetrabutylammonium bromide (TBABr). In order to achieve a broader knowledge of the enzyme-additive interactions, in this paper the activity and stability of alpha-chymotrypsin were tested in the presence of additives with slightly modified bulky ammonium groups. The effect of three additives with a benzylic group as substituent (benzyltrimethylammonium bromide (BzTMABr), benzyltributylammonium bromide (BzTBABr) and benzyldodecyldimethylammonium bromide (BzDDABr)) was investigated. A significant increase in instantaneous activity, but a deactivation of enzyme, faster than in pure buffer, was observed. Moreover, two novel dicationic salts, (1, 8-bis(tributylammonium)octane dibromide (bisBOAB) and 1, 4-bis(tributylammonium)xylene dibromide (bisBAB)) were designed and synthesized in order to evaluate the effect of two tributylammonium head groups with a different spacer. BisBOAB provoked superactivation and stabilization effects in a way similar to the "homologue" TBABr, but at lower concentration. In contrast, when the benzyl group was constrained within the spacer structure, the obtained superactivity was lower than in the presence of a more flexible hydrocarbon chain spacer, and enzyme deactivation was faster. Molecular modelling studies allowed us to rationalize the hypotheses derived from kinetic evidence. The results confirmed that the improvement in the catalytic properties observed in the presence of additives with a bulky, hydrophobic ammonium head group could be addressed to an increase in the overall hydrophobicity of the alpha-chymotrypsin catalytic site.
Idioma: Inglés
DOI: 10.1039/c6ra07425a
Año: 2016
Publicado en: RSC Advances 6, 52 (2016), 46202-46211
ISSN: 2046-2069
Factor impacto JCR: 3.108 (2016)
Categ. JCR: CHEMISTRY, MULTIDISCIPLINARY rank: 59 / 166 = 0.355 (2016) - Q2 - T2
Factor impacto SCIMAGO: 0.889 - Chemistry (miscellaneous) (Q1) - Chemical Engineering (miscellaneous) (Q1)
Tipo y forma: Article (Published version)
You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use. You may not use the material for commercial purposes.
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Idioma: Inglés
DOI: 10.1039/c6ra07425a
Año: 2016
Publicado en: RSC Advances 6, 52 (2016), 46202-46211
ISSN: 2046-2069
Factor impacto JCR: 3.108 (2016)
Categ. JCR: CHEMISTRY, MULTIDISCIPLINARY rank: 59 / 166 = 0.355 (2016) - Q2 - T2
Factor impacto SCIMAGO: 0.889 - Chemistry (miscellaneous) (Q1) - Chemical Engineering (miscellaneous) (Q1)
Tipo y forma: Article (Published version)
You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use. You may not use the material for commercial purposes. Exportado de SIDERAL (2020-02-21-13:52:53)
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Record created 2018-06-14, last modified 2020-02-21