title: Enhancement of electrochemical signal on gold electrodes by polyvalent esterase-dendrimer clusters.
abstract: 5'-Maleimide-oligodeoxynucleotide was conjugated with single sulfhydryl group of cystamine core poly(amidoamine) dendrimers of different generations. Amino groups on the dendrimer moiety were modified with maleimide and coupled to the cysteine 118 of esterase 2 from Alicyclobacillus acidocaldarius in a site-specific manner. Polyvalent esterase-dendrimer-oligodeoxynucleotide clusters were hybridized to capture oligodeoxynucleotides immobilized on a gold electrode. The amperometric signal of p-aminophenol was detected following the esterase-catalyzed hydrolysis of p-aminophenylbutyrate. The multiple anchoring of the esterase reporter via generation 3-and generation 5-derived clusters exhibited 10- and 100-fold signal enhancement, respectively, as compared to monovalent esterase-oligonucleotide conjugate. The polyvalent and monovalent reporters were comparable in their abilities regarding mismatch discrimination.
authors.affiliation: Laboratorium für Biochemie, Universität Bayreuth, Universitätstrasse 30, 95440 Bayreuth, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Humenik
authors.forename: Christopher
authors.initials: C
authors.lastname: Pöhlmann
authors.forename: Yiran
authors.initials: Y
authors.lastname: Wang
authors.forename: Mathias
authors.initials: M
authors.lastname: Sprinzl
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D015374:Biosensing Techniques; D004247:DNA / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D050091:Dendrimers; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D004950:Esterases / Q000737:chemistry* / Q000378:metabolism; D006046:Gold; D009693:Nucleic Acid Hybridization; D009838:Oligodeoxyribonucleotides / Q000378:metabolism; D011073:Polyamines / Q000737:chemistry* / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D050091:Dendrimers; D009838:Oligodeoxyribonucleotides; C104700:PAMAM Starburst; D011073:Polyamines; D006046:Gold; D004247:DNA; D004950:Esterases