Abstract
The effects of applied external hydrostatic pressure on submicrosecond lipid motions in DPPC4 bilayers have been examined using coronene (a long-lived planar fluorescent molecule) and DPH. Steady-state fluorescence emission anisotropy (EA) values (<r>) obtained for probe-labeled DPPC SUVs measured at different fixed temperatures above T c as a function of increasing hydrostatic pressure reveal pressure-induced lipid phase transition profiles. For coronene-labeled samples, the observed lipid “melt” profiles are broad and shifted to higher midpoint EA pressure values (P 1/2) compared with corresponding DPH-labeled SUVs at the same temperature. The data suggest lipid motions occurring on the submicrosecond time scale, detected only by using a long-lived fluorescence probe, which occur well above the normally reported “fluid–gel” lipid phase transition. Slopes of the pressure-to-temperature equivalence plots (dP 1/2/dT = 39 bar/K) obtained for DPH-or coronene-labeled DPPC SUVs are identical within experimental error and reflect probe independence. For DPH, the slope of the P 1/2(T) plot provides the expected phase transition phospholipid volume change. However, intercept values (at P 1/2 = 1 bar) or apparent phase transition temperatures obtained from the equivalence plots for the two probes are not equal. Differences appear to arise due to the very disparate fluorescence lifetime values of the two probes, which result in rotational sensitivity of coronene to gel lipid volume fluctuations occurring during the extended time window provided by coronene fluorescence.
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REFERENCES
A. W. M. Rietveld and S. T. Ferreira (1996) Biochemistry 35, 7743–7751.
S. Dallet and M.-D. Legoy (1996) Biochim. Biophys. Acta 1294, 15–24.
J. L. Silva (1993) Annu. Rev. Phys. Chem. 44, 89–113.
L. Erijman, A. A. Paladini, G. H. Lorimer, and G. Weber (1993) J. Biol. Chem. 268, 25914–25919.
P. L.-G. Chong and G. Weber (1983) Biochemistry 22, 5544–5550.
P. L.-G. Chong, B. W. van der Meer, and T. E. Thompson (1985) Biochim. Biophys. Acta 813, 253–265.
M. Sassaroli, M. Vauhkonen, P. Somerharju, and S. Scarlata (1993) Biophys. J. 64, 137–149.
C. R. Mateo, P. Tauc, and J.-C. Brochon, (1993) Biophys. J. 65, 2248–2260.
L. Davenport and P. Targowski (1996) Biophys. J. 71, 1837–1852.
L. Davenport, J. R. Knutson, and L. Brand (1986) Biochemistry 25, 1811–1816.
L. A. Chen, R. E. Dale, S. Roth, and L. Brand (1977) J. Biol. Chem. 252, 7500–7510.
L. Davenport (1997) in L. Brand and M. L. Johnson (Eds), Methods in Enzymology, Vol. 278, Academic Press, New York, pp. 487–512.
C. W. F. McClare (1971) Anal. Biochem. 39, 527–530.
A. A. Paladini and G. Weber (1981) Rev. Sci. Instrum. 52, 419–429.
P. Targowski and L. Davenport (1998) Analytical Biochemistry, submitted for publication.
R. F. Chen and R. L. Bowman (1963) Science 147, 729–732.
B. R. Lentz, Y. Barenholz, and T. E. Thompson (1976) Biochemistry 15, 4529–4537.
S. Fischkoff and J. M. Vanderkooi (1975) J. Gen. Physiol. 65, 663–676.
A. K. Tan and R. Ramsey (1993) Biochemistry 32, 2137–2143.
L. Davenport, J. R. Knutson, and L. Brand, (1986) Biochemistry 25, 1811–1816.
L. Davenport and P. Targowski (1995) J. Fluoresc. 5, 9–18.
L. Davenport, J. Z. Wang, and J. R. Knutson (1989) in A. Butterfield (Ed.), Biological and Synthetic Membranes, Alan R. Liss, New York, pp. 97–106.
J. F. Nagle and J. L. Scott, Jr. (1978) Biochim. Biophys. Acta 513, 236–243.
D. Hoekstra (1982) Biochemistry 21, 2833–2840.
N.-I. Liu and R. L. Kay (1977) Biochemistry 16, 3484–3486.
S. Mabrey and J. M. Sturtevant (1976) Proc. Natl. Acad. Sci. USA 73, 3862–3866.
B. DeKruiff, R. A. Demel, A. J. Slotboom, L. L. M. VanDeenen, and A. F. Rosenthal (1973) Biochim. Biophys. Acta 307, 1–19.
L. Davenport, P. Targowski, and J. R. Knutson (1995) Biophys. J. 68, A303.
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Targowski, P., Davenport, L. Pressure Effects on Submicrosecond Phospholipid Dynamics Using a Long-Lived Fluorescence Probe. Journal of Fluorescence 8, 121–128 (1998). https://doi.org/10.1023/A:1022594224866
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DOI: https://doi.org/10.1023/A:1022594224866