+ Site Statistics
References:
52,572,879
Abstracts:
28,705,754
PMIDs:
27,750,366
DOIs:
25,464,004
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Inverted micellar intermediates and the transitions between lamellar, cubic, and inverted hexagonal lipid phases. I. Mechanism of the L alpha----HII phase transitions



Inverted micellar intermediates and the transitions between lamellar, cubic, and inverted hexagonal lipid phases. I. Mechanism of the L alpha----HII phase transitions



Biophysical Journal 49(6): 1155-1170



A model for the thermotropic transitions between lamellar (L alpha) and inverted hexagonal (HII) phases is developed. According to this model, the first structures to form during the L alpha----HII transition are inverted micellar intermediates (IMI). The structure, formation rates, and half-lives of IMI ("lipidic particles") were described previously. IMI coalesce in the planes between apposed bilayers to form two types of HII phase precursors. The first is a monolayer-encapsulated HII tube (RMI), which forms via coalescence of IMI in pearl-string fashion. These structures have been proposed previously based on electron microscopic evidence. I show that if only RMI form, L alpha in equilibrium HII transitions cannot occur on observed time scales (faster than seconds). I propose that a second type of intermediate, a line defect (LD), forms as well. LD should form via IMI-IMI coalescence in significant numbers, and elongate rapidly into structures consisting of two apposed halves of HII tubes. Transitions via LD can occur in less than seconds, the time depending on the fraction of IMI-IMI coalescence events producing LD and the number of IMI per unit of bilayer area. Hysteresis in the phase transition temperature may be due to the difference in water content of the two phases and their low water permeabilities. The model is in qualitative agreement with morphological, NMR, and x-ray diffraction data on phospholipid systems. The results are relevant to IMI-mediated interactions between unilamellar bilayer vesicles, and to the structure of inverted cubic phases observed in some phospholipid systems. These will be discussed in subsequent publications (D. P. Siegel, manuscript in preparation).

Please choose payment method:






(PDF emailed within 0-6 h: $19.90)

Accession: 040500089

Download citation: RISBibTeXText

PMID: 3719074

DOI: 10.1016/s0006-3495(86)83744-4


Related references

Inverted micellar intermediates and the transitions between lamellar, cubic, and inverted hexagonal amphiphile phases. III. Isotropic and inverted cubic state formation via intermediates in transitions between L alpha and HII phases. Chemistry and Physics of Lipids 42(4): 279-302, 1986

Inverted micellar intermediates and the transitions between lamellar, cubic, and inverted hexagonal amphiphile phases. III. Isotropic and inverted cubic state formation via intermediates in transitions between Lα and HII phases. Chemistry and Physics of Lipids 42(4): 279-301, 1986

Inverted micellar intermediates and the transitions between lamellar cubic and inverted hexagonal amphiphile phases. Biophysical Journal 45(2 PART 2): 196A, 1984

Inverted micellar intermediates and the transitions between lamellar, cubic, and inverted hexagonal lipid phases. II. Implications for membrane-membrane interactions and membrane fusion. Biophysical Journal 49(6): 1171-1183, 1986

A stalk-mediated mechanism for lamellar/inverted cubic and lamellar/inverted hexagonal phase transitions. Biophysical Journal 66(2 PART 2): A174, 1994

Kinetics and mechanism of transitions involving the lamellar, cubic, inverted hexagonal, and fluid isotropic phases of hydrated monoacylglycerides monitored by time-resolved X-ray diffraction. Biochemistry 26(20): 6349-6363, 1987

Mechanism of the transitions between lamellar and inverted hexagonal phases. Biophysical Journal 47(2 PART 2): 250A, 1985

Lamellar inverted cubic l alpha iii phase transitions in n monomethylated dioleoylphosphatidylethanolamine dope me. Biophysical Journal 55(2 PART 2): 28A, 1989

The mechanism of lamellar-to-inverted hexagonal phase transitions in phosphatidylethanolamine: implications for membrane fusion mechanisms. Biophysical Journal 73(6): 3089-3111, 1997

Membrane membrane interactions via intermediates in lamellar to inverted hexagonal phase transitions. Sowers, A E (Ed ) Cell Fusion Xix+540p Plenum Press: New York, New York, Usa; London, England, Uk Illus 181-208, 1987

The mechanism of lamellar-to-inverted hexagonal phase transitions: A study using temperature-jump cryo-electron microscopy. Biophysical Journal 66(2 PART 1): 402-414, 1994

Calorimetric studies of the gel-fluid (L.beta.-L.alpha.) and lamellar-inverted hexagonal (L.alpha.-Hii) phase transitions in dialkyl- and diacylphosphatidylethanolamines. Biochemistry 22(5): 1280-1289, 1983

Formation of monolayers and bilayer foam films from lamellar, inverted hexagonal and cubic lipid phases. European Biophysics Journal 31(8): 626-632, 2003

Calorimetric studies of the gel fluid l beta l alpha and lamellar inverted hexagonal l alpha hii phase transitions in di alkylphosphatidyl ethanolamines and di acylphosphatidyl ethanolamines. Biochemistry 22(5): 1280-1289, 1983

Calorimetric studies of the gel-fluid (Lb-La) and lamellar-inverted hexagonal (La-HII) phase transitions in dialkyl- and diacylphosphatidylethanolamines. Biochemistry (American Chemical Society) 22: 80-9, 1983