Abstract

Confocal imaging and fluorescence correlation spectroscopy (FCS) was applied towards characterization of lipid phase behavior and diffusion measurements in model lipid membranes. Giant unilamellar vesicles (GUVs) of defined lipid composition were first imaged by confocal fluorescence microscopy. Phase separation was visualized by partitioning of fluorescent lipid analogs with different fatty acid chain lengths into the coexisting phases. Cholesterol induces a marked change in the shapes of the phase domains for the binary mixture of DLPC1/DPPC. Characterization of the dynamics by measuring diffusion coefficients by FCS was carried out in liquid disordered (L__, liquid ordered (Lo) and gel phase (L__. The two-phase region for the binary mixture DLPC/DPPC (L_/L_) was identified by dual mode dynamics recognized in the shapes of the FCS autocorrelation curves. For binary mixtures of DLPC/cholesterol and DMPC/cholesterol, a continuous gradual transition of diffusion coefficients from high values (3.9 x 10-8 cm2/s) in the pure phospholipid down to tenfold slower diffusion as cholesterol was increased up to the phase boundary at 67 mol%.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Center for Research Resources (NCRR)
Type
Biotechnology Resource Grants (P41)
Project #
2P41RR004224-11
Application #
6121890
Study Section
Project Start
1998-09-30
Project End
1999-08-31
Budget Start
1997-10-01
Budget End
1998-09-30
Support Year
11
Fiscal Year
1998
Total Cost
Indirect Cost

  Institution

Name
Cornell University
Department
Type
DUNS #
City
Ithaca
State
NY
Country
United States
Zip Code
14850

  Publications

Migone, Fernando F; Cowan, Robert G; Williams, Rebecca M et al. (2016) In vivo imaging reveals an essential role of vasoconstriction in rupture of the ovarian follicle at ovulation. Proc Natl Acad Sci U S A 113:2294-9
O'Dell, Ryan S; Cameron, David A; Zipfel, Warren R et al. (2015) Reelin Prevents Apical Neurite Retraction during Terminal Translocation and Dendrite Initiation. J Neurosci 35:10659-74
Byrnes, Laura J; Singh, Avtar; Szeto, Kylan et al. (2013) Structural basis for conformational switching and GTP loading of the large G protein atlastin. EMBO J 32:369-84
Jain, Manu; Robinson, Brian D; Scherr, Douglas S et al. (2012) Multiphoton microscopy in the evaluation of human bladder biopsies. Arch Pathol Lab Med 136:517-26
Degala, Satish; Williams, Rebecca; Zipfel, Warren et al. (2012) Calcium signaling in response to fluid flow by chondrocytes in 3D alginate culture. J Orthop Res 30:793-9
O'Dell, Ryan S; Ustine, Candida J M; Cameron, David A et al. (2012) Layer 6 cortical neurons require Reelin-Dab1 signaling for cellular orientation, Golgi deployment, and directed neurite growth into the marginal zone. Neural Dev 7:25
McMullen, J D; Kwan, A C; Williams, R M et al. (2011) Enhancing collection efficiency in large field of view multiphoton microscopy. J Microsc 241:119-24
Kim, Sally A; Sanabria, Hugo; Digman, Michelle A et al. (2010) Quantifying translational mobility in neurons: comparison between current optical techniques. J Neurosci 30:16409-16
Bowles, Robby D; Williams, Rebecca M; Zipfel, Warren R et al. (2010) Self-assembly of aligned tissue-engineered annulus fibrosus and intervertebral disc composite via collagen gel contraction. Tissue Eng Part A 16:1339-48
McMullen, Jesse D; Zipfel, Warren R (2010) A multiphoton objective design with incorporated beam splitter for enhanced fluorescence collection. Opt Express 18:5390-8

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