Measuring the Probability of Receptor Extraction From the Cell Membrane

Abstract

Recently, there has been an increasing interest in measuring the interaction forces between cell adhesion receptors and their ligands [1–3]. These molecules are either anchored on the membrane of a cell or coated on the surface of a substratum. The two surfaces are joined together as a result of the formation of non-covalent bonds between the receptors and ligands. The forces are measured when the two surfaces are separated. In a theoretical paper published nineteen years ago, George Bell estimated the force required to break a receptor-ligand bond and that required to uproot the receptor from the cell membrane to be of the same order of magnitude [4]. The interpretation of the force data therefore requires the knowledge of detachment mode, i.e., via adhesive mechanism if the receptor-ligand bond is dissociated or via cohesive mechanism if the receptor-membrane anchor is disrupted.

Memory in Repetitive Protein–Protein Interaction Series – in Memory of the Late Professor Robert M. Nerem

“…10 During the retraction phase of the contact-retraction cycles, the FcγRIIIa-GPI molecule might be uprooted from the cell membrane because the GPI anchor is thought to be weaker than the antigen–antibody bond. 34 In the fourth case, GP1bα on the platelet membrane binds the A1 domain of the plasma protein VWF to initiate the hemostatic and thrombotic cascade. 18 VWF uses the A3 domain interaction with collagen to immobilize on subendothelial surface of disrupted blood vessel wall.…”

“…Since a full sequence of test cycles usually takes several minutes to complete experimentally, the memory effect accumulation has an intermediate timescale of minutes. We have developed a phenomenological model for this process type that exhibits a cumulative effect over a progressive running adhesion frequency change, capturing the memory effect by an irreversibility index I m 34 (see Eq. 6 in Model development).…”

“…Since a full repeated test cycle sequence usually takes several minutes to complete experimentally, such memory effect has an intermediate timescale of minutes. Here we used a phenomenological model for this process type that exhibits a cumulative effect over a progressive running adhesion frequency change: 34 where F j is the random variable for the running adhesion frequency over j repetitive adhesion tests. E ( F j ) and V ( F j ) are the expected average and variance of F j, respectively.…”