000070908 001__ 70908
000070908 005__ 20200221144346.0
000070908 0247_ $$2doi$$a10.1039/c6ra07425a
000070908 0248_ $$2sideral$$a106255
000070908 037__ $$aART-2016-106255
000070908 041__ $$aeng
000070908 100__ $$0(orcid)0000-0001-6995-4302$$aDe Matteis, L.
000070908 245__ $$aalpha-Chymotrypsin superactivity in quaternary ammonium salt solution: kinetic and computational studies
000070908 260__ $$c2016
000070908 5060_ $$aAccess copy available to the general public$$fUnrestricted
000070908 5203_ $$aAs previously reported, quaternary ammonium salts with bulky hydrophobic portions provoke a superactivation of alpha-chymotrypsin in aqueous solution: this is the case of the surfactant cetyltributylammonium bromide (CTBABr) and the corresponding salt tetrabutylammonium bromide (TBABr). In order to achieve a broader knowledge of the enzyme-additive interactions, in this paper the activity and stability of alpha-chymotrypsin were tested in the presence of additives with slightly modified bulky ammonium groups. The effect of three additives with a benzylic group as substituent (benzyltrimethylammonium bromide (BzTMABr), benzyltributylammonium bromide (BzTBABr) and benzyldodecyldimethylammonium bromide (BzDDABr)) was investigated. A significant increase in instantaneous activity, but a deactivation of enzyme, faster than in pure buffer, was observed. Moreover, two novel dicationic salts, (1, 8-bis(tributylammonium)octane dibromide (bisBOAB) and 1, 4-bis(tributylammonium)xylene dibromide (bisBAB)) were designed and synthesized in order to evaluate the effect of two tributylammonium head groups with a different spacer. BisBOAB provoked superactivation and stabilization effects in a way similar to the "homologue" TBABr, but at lower concentration. In contrast, when the benzyl group was constrained within the spacer structure, the obtained superactivity was lower than in the presence of a more flexible hydrocarbon chain spacer, and enzyme deactivation was faster. Molecular modelling studies allowed us to rationalize the hypotheses derived from kinetic evidence. The results confirmed that the improvement in the catalytic properties observed in the presence of additives with a bulky, hydrophobic ammonium head group could be addressed to an increase in the overall hydrophobicity of the alpha-chymotrypsin catalytic site.
000070908 540__ $$9info:eu-repo/semantics/openAccess$$aby-nc$$uhttp://creativecommons.org/licenses/by-nc/3.0/es/
000070908 590__ $$a3.108$$b2016
000070908 591__ $$aCHEMISTRY, MULTIDISCIPLINARY$$b59 / 166 = 0.355$$c2016$$dQ2$$eT2
000070908 592__ $$a0.889$$b2016
000070908 593__ $$aChemistry (miscellaneous)$$c2016$$dQ1
000070908 593__ $$aChemical Engineering (miscellaneous)$$c2016$$dQ1
000070908 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/publishedVersion
000070908 700__ $$aDi Renzo, F.
000070908 700__ $$aGermani, R.
000070908 700__ $$aGoracci, L.
000070908 700__ $$aSpreti, N.
000070908 700__ $$aTiecco, M.
000070908 773__ $$g6, 52 (2016), 46202-46211$$pRSC ADVANCES$$tRSC Advances$$x2046-2069
000070908 8564_ $$s440365$$uhttps://zaguan.unizar.es/record/70908/files/texto_completo.pdf$$yVersión publicada
000070908 8564_ $$s109909$$uhttps://zaguan.unizar.es/record/70908/files/texto_completo.jpg?subformat=icon$$xicon$$yVersión publicada
000070908 909CO $$ooai:zaguan.unizar.es:70908$$particulos$$pdriver
000070908 951__ $$a2020-02-21-13:52:53
000070908 980__ $$aARTICLE