Detergent-Mediated Photosystem I (PS I) Based Proteoliposome Formation: A First Step Towards Bio-Mimetic Device Fabrication

We investigate the role of detergent-mediated protein reconstitution in incorporating photosynthetic membrane proteins, Photosystem I (PS I), into biomimetic lipid vesicles. The underlying motivation behind our research effort is to fabricate Photosystem I (PS I) based bio-hybrid opto-electronic devices. Our recent investigations on the interaction of two nonionic detergents n-dodecyl-β-D-maltoside (DDM) and Triton X-100 (TX-100) with two types of phospholipids, namely DPhPC (1,2-diphytanoyl-sn-glycero-3-phosphocholine) and DPPG (1,2-dipalmitoyl-sn-glycero-3-phospho-(1'-rac-glycerol)), revealed the ideal detergent/lipid candidates for proteoliposome formation. By utilizing these detergent/lipid combinations, the current work examines the nature of PS I-lipid interactions in colloidal solutions with the aid of scanning probe microscopy, dynamic light scattering and cryo-transmission electron microscopy imaging. In turn, the aforementioned study provides valuable insight into mimicking the naturally occurring protein-phospholipid interactions in photosynthetic thylakoid membranes. In future, these bio-mimetic systems shall facilitate easy incorporation of directionally oriented proteoliposomes into novel bio-hybrid devices.