title: Evaluating the Equilibrium Association Constant between ArtinM Lectin and Myeloid Leukemia Cells by Impedimetric and Piezoelectric Label Free Approaches.
abstract: Label-free methods for evaluating lectin-cell binding have been developed to determine the lectin-carbohydrate interactions in the context of cell-surface oligosaccharides. In the present study, mass loading and electrochemical transducer signals were compared to characterize the interaction between lectin and cellular membranes by measuring the equilibrium association constant, Ka , between ArtinM lectin and the carbohydrate sites of NB4 leukemia cells. By functionalizing sensor interfaces with ArtinM, it was possible to determine Ka over a range of leukemia cell concentrations to construct analytical curves from impedimetric and/or mass-associated frequency shifts with analytical signals following a Langmuir pattern. Using the Langmuir isotherm-binding model, the Ka obtained were (8.9 ± 1.0) × 10(-5) mL/cell and (1.05 ± 0.09) × 10(-6) mL/cell with the electrochemical impedance spectroscopy (EIS) and quartz crystal microbalance (QCM) methods, respectively. The observed differences were attributed to the intrinsic characteristic sensitivity of each method in following Langmuir isotherm premises.
authors.affiliation: Department of Physical Chemistry, Chemistry Institute, São Paulo State University (UNESP), 55 Prof. Francisco Degni Street, 14800-060, São Paulo, Brazil; E-Mails: nandaferdecarvalho@gmail.com (F.C.C.); denisecm86@gmail.com (D.C.M.); santosadriano29@gmail.com (A.S.).
authors.forename: Fernanda C
authors.initials: FC
authors.lastname: Carvalho
authors.affiliation: Department of Physical Chemistry, Chemistry Institute, São Paulo State University (UNESP), 55 Prof. Francisco Degni Street, 14800-060, São Paulo, Brazil; E-Mails: nandaferdecarvalho@gmail.com (F.C.C.); denisecm86@gmail.com (D.C.M.); santosadriano29@gmail.com (A.S.).
authors.forename: Denise C
authors.initials: DC
authors.lastname: Martins
authors.affiliation: Department of Physical Chemistry, Chemistry Institute, São Paulo State University (UNESP), 55 Prof. Francisco Degni Street, 14800-060, São Paulo, Brazil; E-Mails: nandaferdecarvalho@gmail.com (F.C.C.); denisecm86@gmail.com (D.C.M.); santosadriano29@gmail.com (A.S.).
authors.forename: Adriano
authors.initials: A
authors.lastname: Santos
authors.affiliation: Department of Cellular and Molecular Biology and Pathogenic Bioagents, Ribeirão Preto Medical School, University of São Paulo (USP), 3900 Bandeirantes Avenue, 14049-900, Ribeirão Preto, São Paulo, Brazil; E-Mail: mcrbarre@fmrp.usp.br.
authors.forename: Maria-Cristina
authors.initials: MC
authors.lastname: Roque-Barreira
authors.affiliation: Department of Physical Chemistry, Chemistry Institute, São Paulo State University (UNESP), 55 Prof. Francisco Degni Street, 14800-060, São Paulo, Brazil; E-Mails: nandaferdecarvalho@gmail.com (F.C.C.); denisecm86@gmail.com (D.C.M.); santosadriano29@gmail.com (A.S.).
authors.forename: Paulo R
authors.initials: PR
authors.lastname: Bueno
keywords: ArtinM; Langmuir isotherm; electrochemical impedance spectroscopy; equilibrium association constant (Ka); lectin; myeloid leukemia cells; quartz crystal microbalance