title: Enzyme hyperactivation system based on a complementary charged pair of polyelectrolytes and substrates.
abstract: Artificial enzyme activators are of great interest for enzyme applications in a wide range of research fields. Here, we report an enzyme hyperactivation system using polyelectrolytes that are complementary to charged substrates. The enzyme activity of α-chymotrypsin (ChT) for a cationic substrate increased 7-fold at pH 7.0 in the presence of anionic poly(acrylic acid) (PAAc) and for an anionic substrate increased 18-fold at pH 7.0 in the presence of cationic poly(allylamine) (PAA). Analysis of salt and pH effects, enzyme kinetics, dynamic light scattering (DLS), and circular dichroism (CD) indicated that the enzyme activation results from favorable electrostatic interactions between oppositely charged substrates and polyelectrolytes surrounding the enzymes. This hyperactivation system does not require laborious mutagenesis or chemical modification of enzymes and thus is relevant to a number of applications.
authors.affiliation: Faculty of Pure and Applied Sciences, University of Tsukuba , 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573, Japan.
authors.forename: Takaaki
authors.initials: T
authors.lastname: Kurinomaru
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Tomita
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Hagihara
authors.forename: Kentaro
authors.initials: K
authors.lastname: Shiraki
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000818:Animals; D002417:Cattle; D002918:Chymotrypsin / Q000737:chemistry*; D004789:Enzyme Activation; D020536:Enzyme Activators / Q000737:chemistry*; D057075:Enzyme Assays; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009842:Oligopeptides / Q000737:chemistry*; D011073:Polyamines / Q000737:chemistry*; D055672:Static Electricity; D013379:Substrate Specificity
chemical_list: D000180:Acrylic Resins; D020536:Enzyme Activators; D009842:Oligopeptides; D011073:Polyamines; C063994:polyallylamine; C006903:carbopol 940; D002918:Chymotrypsin; C117608:alpha-chymotrypsin