Open AccessCharacterization of Folic Acid and Poly(amidoamine) Dendrimer Interactions with Folate Binding Protein: A Force-Pulling Study
Author(s) -
Pascale R. Leroueil,
Stassi DiMaggio,
Abigail N. Leistra,
Craig Blanchette,
Christine A. Orme,
Kumar Sinniah,
Bradford G. Orr,
Mark M. Banaszak Holl
Publication year - 2015
Publication title -
the journal of physical chemistry. b
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.864
H-Index - 392
eISSN - 1520-6106
pISSN - 1520-5207
DOI - 10.1021/acs.jpcb.5b05391
Subject(s) - amidoamine , poly(amidoamine) , dendrimer , van der waals force , folic acid , chemistry , atomic force microscopy , binding energy , biophysics , crystallography , materials science , molecule , nanotechnology , polymer chemistry , organic chemistry , physics , biology , atomic physics , medicine
Atomic force microscopy force-pulling experiments have been used to measure the binding forces between folic acid (FA) conjugated poly(amidoamine) (PAMAM) dendrimers and folate binding protein (FBP). The generation 5 (G5) PAMAM conjugates contained an average of 2.7, 4.7, and 7.2 FA per dendrimer. The most probable rupture force was measured to be 83, 201, and 189 pN for G5-FA2.7, G5-FA4.7, and G5-FA7.2, respectively. Folic acid blocking experiments for G5-FA7.2 reduced the frequency of successful binding events and increased the magnitude of the average rupture force to 274 pN. The force data are interpreted as arising from a network of van der Waals and electrostatic interactions that form between FBP and G5 PAMAM dendrimer, resulting in a binding strength far greater than that expected for an interaction between FA and FBP alone.