title: Lectins and/or xyloglucans/alginate layers as supports for immobilization of dengue virus particles.
abstract: Formation of stable thin films of mixed xyloglucan (XG) and alginate (ALG) onto Si/SiO(2) wafers was achieved under pH 11.6, 50mM CaCl(2), and at 70 degrees C. XG-ALG films presented mean thickness of (16+/-2)nm and globules rich surface, as evidenced by means of ellipsometry and atomic force microscopy (AFM), respectively. The adsorption of two glucose/mannose-binding seed (Canavalia ensiformis and Dioclea altissima) lectins, coded here as ConA and DAlt, onto XG-ALG surfaces took place under pH 5. Under this condition both lectins present positive net charge. ConA and DAlt adsorbed irreversibly onto XG-ALG forming homogenous monolayers approximately (4+/-1)nm thick. Lectins adsorption was mainly driven by electrostatic interaction between lectins positively charged residues and carboxylated (negatively charged) ALG groups. Adhesion of four serotypes of dengue virus, DENV (1-4), particles to XG-ALG surfaces were observed by ellipsometry and AFM. The attachment of dengue particles onto XG-ALG films might be mediated by (i) H bonding between E protein (located at virus particle surface) polar residues and hydroxyl groups present on XG-ALG surfaces and (ii) electrostatic interaction between E protein positively charged residues and ALG carboxylic groups. DENV-4 serotype presented the weakest adsorption onto XG-ALG surfaces, indicating that E protein on DENV-4 surface presents net charge (amino acid sequence) different from E proteins of other serotypes. All four DENV particles serotypes adsorbed similarly onto lectin films adsorbed. Nevertheless, the addition of 0.005mol/L of mannose prevented dengue particles from adsorbing onto lectin films. XG-ALG and lectin layers serve as potential materials for the development of diagnostic methods for dengue.
authors.affiliation: Instituto de Química, Universidade de São Paulo, 05513-970 São Paulo, Brazil.
authors.forename: Edla M A
authors.initials: EM
authors.lastname: Pereira
authors.forename: Maria Rita
authors.initials: MR
authors.lastname: Sierakowski
authors.forename: Tatiane A
authors.initials: TA
authors.lastname: Jó
authors.forename: Renato A
authors.initials: RA
authors.lastname: Moreira
authors.forename: Ana Cristina O
authors.initials: AC
authors.lastname: Monteiro-Moreira
authors.forename: Rafael F O
authors.initials: RF
authors.lastname: França
authors.forename: Benedito A L
authors.initials: BA
authors.lastname: Fonseca
authors.forename: Denise F S
authors.initials: DF
authors.lastname: Petri
mesh_terms: D000464:Alginates / Q000737:chemistry* / Q000378:metabolism; D003208:Concanavalin A / Q000737:chemistry / Q000378:metabolism; D003715:Dengue / Q000378:metabolism; D003716:Dengue Virus / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D005936:Glucans / Q000737:chemistry* / Q000378:metabolism; D020723:Glucuronic Acid / Q000737:chemistry / Q000378:metabolism; D006603:Hexuronic Acids / Q000737:chemistry / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D037102:Lectins / Q000737:chemistry* / Q000378:metabolism; D018625:Microscopy, Atomic Force; D012822:Silicon Dioxide / Q000737:chemistry / Q000378:metabolism; D017550:Spectroscopy, Fourier Transform Infrared; D014771:Virion / Q000737:chemistry / Q000378:metabolism*; D014990:Xylans / Q000737:chemistry* / Q000378:metabolism
chemical_list: D000464:Alginates; D005936:Glucans; D006603:Hexuronic Acids; D037102:Lectins; D014990:Xylans; D003208:Concanavalin A; C029353:xyloglucan; D012822:Silicon Dioxide; D020723:Glucuronic Acid