Influence of membrane surface charge on adsorption of complement proteins onto supported lipid bilayers.
The complement system is an important part of the innate immune response, and there is great interest in understanding how complement proteins interact with lipid membrane interfaces, especially in the context of recognizing foreign particulates (e.g., liposomal nanomedicines). Herein, a supported lipid bilayer platform was employed in order to investigate the effect of membrane surface charge (positive, negative, or neutral) on the adsorption of three complement proteins. Quartz crystal microbalance-dissipation (QCM-D) experiments measured the real-time kinetics and total uptake of protein adsorption onto supported lipid bilayers. The results demonstrate that all three proteins exhibit preferential, mainly irreversible adsorption onto negatively charged lipid bilayers, yet there was also significant variation in total uptake and the relative degree of adsorption onto negatively charged bilayers versus neutral and positively charged bilayers. The total uptake was also observed to strongly depend on the bulk protein concentration. Taken together, our findings contribute to a broader understanding of the factors which influence adsorption of complement proteins onto lipid membranes and offer guidance towards the design of synthetic lipid bilayers with immunocompetent features.
School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore; Centre for Biomimetic Sensor Science, Nanyang Technological University, 50 Nanyang Drive, 637553, Singapore; Institute of Molecular and Cell Biology, Agency for Science Technology and Research, Singapore.
Saziye
S
Yorulmaz
School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore; Centre for Biomimetic Sensor Science, Nanyang Technological University, 50 Nanyang Drive, 637553, Singapore.
Joshua A
JA
Jackman
Institute of Molecular and Cell Biology, Agency for Science Technology and Research, Singapore; Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 117599, Singapore; Singapore Eye Research Institute, Singapore.
Walter
W
Hunziker
School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore; Centre for Biomimetic Sensor Science, Nanyang Technological University, 50 Nanyang Drive, 637553, Singapore; School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, 637459, Singapore. Electronic address: njcho@ntu.edu.sg.
Nam-Joon
NJ
Cho
D000327:Adsorption; D003165:Complement System Proteins / Q000378:metabolism*; D006801:Humans; D008051:Lipid Bilayers; D013499:Surface Properties
D008051:Lipid Bilayers; D003165:Complement System Proteins
Biomaterial interfaces; Complement activation; Protein adsorption; Quartz crystal microbalance; Supported lipid bilayer