+ Site Statistics
+ 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

A calorimetric and spectroscopic comparison of the effects of lathosterol and cholesterol on the thermotropic phase behavior and organization of dipalmitoylphosphatidylcholine bilayer membranes



A calorimetric and spectroscopic comparison of the effects of lathosterol and cholesterol on the thermotropic phase behavior and organization of dipalmitoylphosphatidylcholine bilayer membranes



Biochemistry 50(46): 9982-9997



We performed differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopic measurements to study the effects of lathosterol (Lath) on the thermotropic phase behavior and organization of dipalmitoylphosphatidylcholine (DPPC) bilayer membranes and compared our results with those previously reported for cholesterol (Chol)/DPPC binary mixtures. Lath is the penultimate intermediate in the biosynthesis of Chol in the Kandutsch-Russell pathway and differs from Chol only in the double bond position in ring B, which is between C7 and C8 in Lath and between C5 and C6 in Chol. Our DSC studies indicate that the incorporation of Lath is more effective than Chol in reducing the temperature and enthalpy of the DPPC pretransition. At lower sterol concentrations (≤10 mol %), incorporation of both Lath and Chol decreases the temperature, enthalpy, and cooperativity of the sharp component of the main phase transition of DPPC to a similar extent, but at higher sterol concentrations, Lath is more effective at decreasing the phase transition temperature, enthalpy, and cooperativity than Chol. These results indicate that at higher concentrations, Lath is more disruptive of DPPC gel-state bilayer packing than Chol is. Moreover, incorporation of Lath decreases the temperature of the broad component of the main phase transition of DPPC, whereas Chol increases it; this difference in the direction and magnitude of the temperature shift is accentuated at higher sterol concentrations. Although at sterol concentrations of ≤20 mol % Lath and Chol are almost equally effective at reducing the enthalpy and cooperativity of the broad component of the main phase transition, at higher sterol levels Lath is less effective than Chol in these regards and does not completely abolish the cooperative hydrocarbon chain melting phase transition at 50 mol %, as does Chol. These latter results indicate that Lath both is more disruptive with respect to the low-temperature state of the sterol-enriched domains of DPPC bilayers and has a lower lateral miscibility in DPPC bilayers than Chol. Our FTIR spectroscopic studies suggest that Lath incorporation produces a less tightly packed bilayer than does Chol at both low (gel state) and high (liquid-crystalline state) temperatures, which is characterized by increased H-bonding between water and the carbonyl groups of the fatty acyl chains in the DPPC bilayer. Overall, our studies indicate that Lath and Chol incorporation can have rather different effects on the thermotropic phase behavior and organization of DPPC bilayers and thus that the position of the double bond in ring B of a sterol molecule can have an appreciable effect on the physical properties of sterol molecules.

Please choose payment method:






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

Accession: 051083698

Download citation: RISBibTeXText

PMID: 21951051

DOI: 10.1021/bi200721j


Related references

A calorimetric and spectroscopic comparison of the effects of ergosterol and cholesterol on the thermotropic phase behavior and organization of dipalmitoylphosphatidylcholine bilayer membranes. Biochimica et Biophysica Acta 1798(3): 376-388, 2010

A calorimetric and spectroscopic comparison of the effects of cholesterol and its sulfur-containing analogs thiocholesterol and cholesterol sulfate on the thermotropic phase behavior and organization of dipalmitoylphosphatidylcholine bilayer membranes. Biochimica et Biophysica Acta 1858(2): 168-180, 2016

A calorimetric and spectroscopic comparison of the effects of cholesterol and its immediate biosynthetic precursors 7-dehydrocholesterol and desmosterol on the thermotropic phase behavior and organization of dipalmitoylphosphatidylcholine bilayer membranes. Chemistry and Physics of Lipids 191: 123-135, 2015

Comparative calorimetric and spectroscopic studies of the effects of lanosterol and cholesterol on the thermotropic phase behavior and organization of dipalmitoylphosphatidylcholine bilayer membranes. Biophysical Journal 91(9): 3327-3340, 2006

A comparative calorimetric and spectroscopic study of the effects of cholesterol and of the plant sterols β-sitosterol and stigmasterol on the thermotropic phase behavior and organization of dipalmitoylphosphatidylcholine bilayer membranes. Biochimica et Biophysica Acta 1848(8): 1629-1638, 2015

Comparative calorimetric and spectroscopic studies of the effects of cholesterol and epicholesterol on the thermotropic phase behaviour of dipalmitoylphosphatidylcholine bilayer membranes. Biochimica et Biophysica Acta 1778(10): 2191-2202, 2008

Calorimetric and spectroscopic studies of the effects of cholesterol on the thermotropic phase behavior and organization of a homologous series of linear saturated phosphatidylglycerol bilayer membranes. Biochimica et Biophysica Acta 1788(2): 345-357, 2009

A comparative calorimetric study of the effects of cholesterol and the plant sterols campesterol and brassicasterol on the thermotropic phase behavior of dipalmitoylphosphatidylcholine bilayer membranes. Biochimica et Biophysica Acta 1838(7): 1941-1949, 2014

Differential scanning calorimetric and Fourier transform infrared spectroscopic studies of the effects of cholesterol on the thermotropic phase behavior and organization of a homologous series of linear saturated phosphatidylserine bilayer membranes. Biophysical Journal 79(4): 2056-2065, 2000

A DSC and FTIR spectroscopic study of the effects of the epimeric cholestan-3-ols and cholestan-3-one on the thermotropic phase behavior and organization of dipalmitoylphosphatidylcholine bilayer membranes: Comparison with their 5-cholesten analogs. Chemistry and Physics of Lipids 187: 34-49, 2015

A DSC and FTIR spectroscopic study of the effects of the epimeric coprostan-3-ols and coprostan-3-one on the thermotropic phase behaviour and organization of dipalmitoylphosphatidylcholine bilayer membranes: Comparison with their 5-cholesten analogues. Chemistry and Physics of Lipids 188: 10-26, 2015

A DSC and FTIR spectroscopic study of the effects of the epimeric 4-cholesten-3-ols and 4-cholesten-3-one on the thermotropic phase behaviour and organization of dipalmitoylphosphatidylcholine bilayer membranes: comparison with their 5-cholesten analogues. Chemistry and Physics of Lipids 177: 71-90, 2014

A comparative differential scanning calorimetry study of the effects of cholesterol and various oxysterols on the thermotropic phase behavior of dipalmitoylphosphatidylcholine bilayer membranes. Chemistry and Physics of Lipids 195: 21-33, 2016

A DSC and FTIR spectroscopic study of the effects of the epimeric 4,6-cholestadien-3-ols and 4,6-cholestadien-3-one on the thermotropic phase behaviour and organization of dipalmitoylphosphatidylcholine bilayer membranes. Chemistry and Physics of Lipids 183: 142-158, 2014

Calorimetric spectroscopic studies of the effects of cholesterol on the thermotropic phase behavior and organization of a homologous series of linear saturated phosphatidylethanolamine bilayers. Biochimica et Biophysica Acta 1416(1-2): 119-134, 1999