Thermodynamic properties of the lipid bilayer transition. Pseudocritical phenomena

Mitaku, Shigeki; Jippo, T.; Kataoka, Ryoichi

doi:10.1016/s0006-3495(83)84379-3

Cited by 81 publications

(61 citation statements)

References 34 publications

(41 reference statements)

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“…Such an inversion of the spectral shift has been interpreted as due to fluctuation between the different phases [30], with kinetics of about 25 ns, and imply per se the coexistence of separate phase domains. This result is in agreement with those obtained by the use of ultrasound techniques [33] and by the measurements of the rotational behavior of the fluorescent coronene [34], where phase fluctuations were found to occur in the range from 20 to 60 ns and from 20 to 200 ns, respectively. Laurdan lifetime measured over all the emission spectrum is 5.9 ns in the gel and 4.0 ns in the liquid-crystalline phase [32].…”

Section: Spectrasupporting

confidence: 91%

Membrane lipid domains and dynamics as detected by Laurdan fluorescence

1995

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(Laurdan) is a membrane probe of recent characterization, which shows high sensitivity to the polarity of its environment. Steady-state Laurdan excitation and emission spectra have different maxima and shape in the two phospholipid phases, due to differences in the polarity and in the amount of dipolar relaxation, ha bilayers composed of a mixture of gel and liquid-crystalline phases, the properties of Laurdan excitation and emission spectra are intermediate between those obtained in the pure phases. These spectral properties are analyzed using the generalized polarization (GP). The GP value can be used for the quantitation of each phase. The wavelength dependence of the GP value is used to ascertain the coexistence of different phase domains in the bilayer. Moreover, by following the evolution of Laurdan emission vs. time after excitation, the kinetics of phase fluctuation in phospholipid vesicles composed of coexisting gel and liquid-crystalline phases was determined. GP measurements performed in several cell lines did not give indications of coexistence of phase domains in their membranes. In natural membranes, Laurdan parameters indicate a homogeneously fluid environment, with restricted molecular motion in comparison with the phospholipid liquid-crystalline phase. The influence of cholesterol on the phase properties of the two phospholipid phases is proposed to be the cause of the phase behavior observed in na~u'al membranes. In bilayers composed of different phospholipids and various cholesterol concentrations, Laurdan response is very similar to that arising from cell membranes. In the absence of cholesterol, from the steady-state and time-resolved measurements of Laurdan in phospholipid vesicles, the condition for the occurrence of separate coexisting domains in the bilayer has been determined: the molecular ratio between the two phases must be in the range between 30% and 70%. Below and above this range, a single homogeneous phase is observed, with the properties of the more concentrated phase, slightly modified by the presence of the other. Moreover, in this concentration range, the calculated dimension of the domains is very small, between 20 and 50 A.

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Section: Spectrasupporting

confidence: 91%

Membrane lipid domains and dynamics as detected by Laurdan fluorescence

1995

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“…So we can treat the precritical system over the swelling region as a critical system [7,8]. The fact that the system does not "know" a priori the order of the transition it will undergo when it swells critically is the base for the theory of critical unbinding of membranes [14], which means the d-spacing can diverge.…”

Section: Determination Of Tcmentioning

confidence: 99%

“…The corresponding critical temperature T c would lie at a temperature just below that of T m , and so is "hidden" by the main transition. Critical behavior is also seen in liposomes by nuclear magnetic resonance (NMR) [7] and ultrasonic absorption [8]. This behavior in phosphatidylcholine membranes, a major component of cell membranes, is believed to be of physiological importance, because small temperature changes change the thickness of the membrane drastically and thus can easily affect protein functions [9,10].…”

Section: Introductionmentioning

confidence: 99%

Sterols sense swelling in lipid bilayers

1999

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In the mimetic membrane system of phosphatidylcholine bilayers, thickening ("pre-critical behavior", "anomalous swelling") of the bilayers is observed, in the vicinity of the main transition, which is nonlinear with temperature. The sterols cholesterol and androsten are used as sensors in a time-resolved simultaneous small-and wide angle x-ray diffraction study to investigate the cause of the thickening. We observe precritical behavior in the pure lipid system, as well as with sterol concentrations less than 15%. To describe the precritical behavior we introduce a theory of precritical phenomena. The good temperature resolution of the data shows that a theory of the influence of fluctuations needs modification. The main cause of the critical behavior appears to be a changing hydration of the bilayer.

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“…12 The idea that the cell membrane may exploit features of critical phenomena is not new, [13][14][15][16] and studies on both biological and model membranes have examined critical behaviors for insight into biological membrane functions. [16][17][18][19][20][21][22] Critical fluctuations in lipid composition have been linked to enzyme function 15,23 and to an anomalous increase in ion permeability. 13 The singular behavior of the diffusion coefficient has been associated with protein mobility 16 and environmental sensitivity.…”

Section: Introductionmentioning

confidence: 99%

Precise and millidegree stable temperature control for fluorescence imaging: Application to phase transitions in lipid membranes

Farkas

Webb

2010

Review of Scientific Instruments

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We present the design of a custom temperature-controlled chamber suitable for water or oil immersion fluorescence microscopy and its application to phase behavior in lipid bilayer vesicles. The apparatus is self-contained and portable, suitable for multiuser microscopy facilities. It offers a higher temperature resolution and stability than any comparable commercial apparatus, on the order of millidegrees. We demonstrate the utility of the system in the study of miscibility transitions in model membranes. The temperature-dependent phase behavior of model membrane systems that display liquid-ordered ͑L o ͒ phase coexistence with the liquid-disordered ͑L d ͒ phase is relevant to understanding the existence of heterogeneities in biological cell plasma membranes, ubiquitously termed "lipid rafts."

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Thermodynamic properties of the lipid bilayer transition. Pseudocritical phenomena

Cited by 81 publications

References 34 publications

Membrane lipid domains and dynamics as detected by Laurdan fluorescence

Membrane lipid domains and dynamics as detected by Laurdan fluorescence

Sterols sense swelling in lipid bilayers

Precise and millidegree stable temperature control for fluorescence imaging: Application to phase transitions in lipid membranes

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