title: Characterizing the adsorption of proteins on glass capillary surfaces using electrospray-differential mobility analysis.
abstract: We quantify the adsorption and desorption of a monoclonal immunoglobulin-G antibody, rituxamab (RmAb), on silica capillary surfaces using electrospray-differential mobility analysis (ES-DMA). We first develop a theory to calculate coverages and desorption rate constants from the ES-DMA data for proteins adsorbing on glass capillaries used to electrospray protein solutions. This model is then used to study the adsorption of RmAb on a bare silica capillary surface. A concentration-independent coverage of ≈4.0 mg/m(2) is found for RmAb concentrations ranging from 0.01 to 0.1 mg/mL. A study of RmAb adsorption to bare silica as a function of pH shows maximum adsorption at its isoelectric point (pI of pH 8.5) consistent with literature. The desorption rate constants are determined to be ≈10(-5) s(-1), consistent with previously reported values, thus suggesting that shear forces in the capillary may not have a considerable effect on desorption. We anticipate that this study will allow ES-DMA to be used as a "label-free" tool to study adsorption of oligomeric and multicomponent protein systems onto fused silica as well as other surface modifications.
authors: Department of Mechanical Engineering, University of Maryland, College Park, Maryland 20742, United States.
authors: Suvajyoti
authors: S
authors: Guha
authors: Joshua R
authors: JR
authors: Wayment
authors: Mingdong
authors: M
authors: Li
authors: Michael J
authors: MJ
authors: Tarlov
authors: Michael R
authors: MR
authors: Zachariah
mesh_terms: D000327:Adsorption; D058846:Antibodies, Monoclonal, Murine-Derived / Q000737:chemistry*; D004560:Electricity; D005898:Glass / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009038:Motion; D000069283:Rituximab; D013499:Surface Properties
chemical_list: D058846:Antibodies, Monoclonal, Murine-Derived; D000069283:Rituximab