title: Cooperative lectin recognition of periodical glycoclusters along DNA duplexes: alternate hybridization and full hybridization.
abstract: We describe herein the construction of periodically, spatially controlled glycoclusters along DNA duplexes and their cooperative lectin recognition. Site-specifically alpha-mannosylated oligodeoxynucleotide 20-mer (Man-ODN20) was synthesized via the phosphoramidite solid-phase synthesis. Alternate hybridization of the Man-ODN20 with the half-sliding complementary ODN 20-mer (hscODN20) gave an alternately prolonged Man-cluster Man-ODN20/hscODN20. The binding of the Man-cluster to FITC-labeled ConA lectin showed sigmoidal fluorescence dependency on the concentration of Man-ODN, indicating that some mannose residues along the repeating DNA duplex were cooperatively bound to ConA (apparent affinity constant: K(af)=2.4 x 10(4)M(-1) and Hill coefficient: n=3.5). The duplex of Man-ODN20 with full complementary ODN 20-mer (fcODN20) was little bound to ConA. The binding behavior of Man-ODN20/hscODN20 is compared with that of the alternately prolonged Gal-cluster Gal-ODN20/hscODN20 previously reported. Duplexes 20-mer, 40-mer, and 60-mer presenting one, two, and three periodic galactoses were also prepared by full hybridization of 20-mer beta-galactosylated oligodeoxynucleotide (Gal-ODN20) with the periodically repeating full complementary 20-mer, 40-mer, and 60-mer ODNs. RCA(120) lectin was found to little bind the 20-mer and 40-mer duplexes and to bind weakly and non-cooperatively the 60-mer duplex (K(af)=1.1 x 10(4)M(-1)). The cooperative lectin recognition of these glycoclusters in relation with the degree of association (DA) of ODN and the numbers of glycosides along the DNA duplex is discussed.
authors.affiliation: Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan.
authors.forename: Yoshinao
authors.initials: Y
authors.lastname: Yamada
authors.forename: Kazunori
authors.initials: K
authors.lastname: Matsuura
authors.forename: Kazukiyo
authors.initials: K
authors.lastname: Kobayashi
mesh_terms: D002850:Chromatography, Gel; D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry* / Q000378:metabolism*; D006031:Glycosylation; D037102:Lectins / Q000737:chemistry* / Q000378:metabolism*; D008358:Mannose / Q000737:chemistry; D015394:Molecular Structure; D008970:Molecular Weight; D013379:Substrate Specificity
chemical_list: D037102:Lectins; D004247:DNA; D008358:Mannose