Adhesion and Stiffness of Biotin-Superavidin Bonds

Publication date: Available online 19 July 2018Source: Colloids and Surfaces B: BiointerfacesAuthor(s): Bahman Farzi, Jan Scrimgeour, Cetin CetinkayaAbstractA non-invasive vibrational spectroscopy technique is introduced and utilized to characterize the average spring constant of a single Superavidin (SAv)-Biotin (Bi).polyethylene glycol (PEG) ligand receptor complex as well as the effective Young’s modulus and adhesion of a layer formed by the SAv-Bi.PEG ligand-receptors. In the reported experiments, SAv coated Polystyrene (PS) particles are deposited on a layer of Bi.PEG receptors, bound to a silicon (Si) substrate by silanization. The substrate and the bonded particles are subjected to a pulsed ultrasonic excitation field and their nanometer scale out-of-plane dynamic responses are acquired using a laser vibrometer. The acquired waveforms are processed to obtain the resonance frequencies of the particle motion. Employing a particle adhesion model, the average spring constant of the single ligand-receptor complex and the effective Young’s modulus and work-of-adhesion of the SAv-Bi.PEG ligand-receptor layer are extracted from the resonance frequencies. The average spring constant of an individual SAv-Bi.PEG bond is approximated as 0.1-0.4 mN/m. The work-of-adhesion and effective Young’s modulus of the SAv-Bi.PEG layer are determined to be 0.54-2.62 J/m2 and 0.15-2.80 MPa, respectively. The compressive Young’s modulus of the SAv-Bi.PEG layer is estimated as 31.0...
Source: Colloids and Surfaces B: Biointerfaces - Category: Biochemistry Source Type: research