Home > Research > NIBIB Intramural Labs > Laboratory of Bioengineering and Physical Science > LBPS Biomedical Instrumentation and Multiscale Imaging > LBPS Biological Atomic Force Microscopy

E-mail this page

Biomembrane Structure & GPCR Dynamics

Collaborative studies with Drs. F. Tokumasu (NIAID), J.A. Dvorak (NIAID), S.-L. Niu (NIAAA), D.C. Mitchell (NIAAA), K Gawrisch (NIAAA), and other scientists, including extramural researcher, Professor G.W. Feigenson, have focused on the structure and dynamics of biological membranes and membrane proteins using AFM, optics, and other related tools. The effect of cholesterol on membrane nanodomains and microdomains has been explored systematically in lipid bilayers.

Liposome preparation, membrane fusion, and phase transition in biomembranes with spatial confinement have been investigated, and their relevance in tuberculosis and malaria is being revealed. The structure and function of rhodopsin, which is representative of a huge family of G-protein coupled receptors (GPCRs), is known to be closely coupled to its biomembrane environment. Our AFM imaging and spectroscopy studies look at individual and/or dimerized rhodopsins while they are arrested in gel-state lipid environment, and then we compare this "arrested" behavior with that of dynamically diffusing and interacting rhodopsins in fluid-state membranes, as well as in native disks of the rod cells in the eyes.

Back to Top

Selected References

Hayakawa E, Tokumasu F, Nardone GA, Jin AJ, Hackley VA, and Dvorak JA: A Mycobacterium tuberculosis-derived lipid inhibits membrane fusion by modulating lipid membrane domains. Biophys J, 93: 4018-30, 2007.

Tokumasu F, Jin AJ, Feigenson GW and Dvorak JA: Nanoscopic lipid domain dynamics revealed by atomic force microscopy. Biophys J, 84: 2609-2618, 2003.

Tokumasu F, Jin AJ, Feigenson GW and Dvorak JA: Atomic Force Microscopy of nanometric liposome adsorption and nanoscopic membrane domain formation. Ultramicroscopy, 97: 217-227, 2003.

Tokumasu F, Jin AJ, and Dvorak JA: Lipid membrane phase behavior elucidated in real time by controlled environment atomic force microscopy. J Electron Microsc, 51: 1-9, 2002.

Choi EJ, Jin AJ, Niu S-L, Smith PD, and Litman BJ: Visualizing individual rhodopsin (a G-protein coupled receptor) molecules in native disk and reconstructed membranes via atomic force microscopy. Tech Proc 2004 Nanotech & Trade, 1: 63-66, 2004.

Back to Top 

Back to AFM Page