Multiplexed silicon photonic sensor arrays enable facile characterization of coagulation protein binding to nanodiscs with variable lipid content
Year: 2017
Type: article
Abstract: Interactions of soluble proteins with the cell membrane are critical within the blood coagulation cascade. Of particular interest are the interactions of γ-carboxyglutamic acid-rich domain-containing clotting proteins with lipids. Variability among conventional analytical methods presents challenges for comparing clotting protein–lipid interactions. Most previous studies have investigated only a single clotting protein and lipid composition and have yielded widely different binding constants. Herein, we demonstrate that a combination of lipid bilayer nanodiscs and a multiplexed silicon photonic analysis technology enables high-throughput probing of many protein–lipid interactions among blood-clotting proteins. This approach allowed direct comparison of the binding constants of prothrombin, factor X, activated factor VII, and activated protein C to seven different binary lipid compositions. In a single experiment, the binding constants of one protein interacting with all lipid compositions were simultaneously determined. A simple surface regeneration then facilitated similar binding measurements for three other coagulation proteins. As expected, our results indicated that all proteins exhibit tighter binding (lower K d ) as the proportion of anionic lipid increases. Interestingly, at high proportions of phosphatidylserine, the K d values of all four proteins began to converge. We also found that although k off values for all four proteins followed trends similar to those observed for the K d values, the variation among the proteins was much lower, indicating that much of the variation came from the kinetic binding ( k on ) of the proteins. These findings indicate that the combination of silicon photonic microring resonator arrays and nanodiscs enables rapid interrogation of biomolecular binding interactions at model cell membrane interfaces.
Source: Journal of Biological Chemistry
Language: English
Subfield: Hematology
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Estimated APC paid: $3,430
OpenAlex ID: W2743264397