Spontaneous formation of small unilamellar vesicles by pH jump: A pH gradient across the bilayer membrane as the driving force

Journal Article · Tue Mar 06 00:00:00 EST 1990 · Biochemistry; (USA)

DOI:https://doi.org/10.1021/bi00461a016· OSTI ID:7008906

Hauser, H ^[1]; Mantsch, H H; Casal, H L ^[2]

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1. Eidgenossische Technische Hochshule, Zurich (Switzerland)
2. National Research Council of Canada, Ottawa, Ontario (Canada)

{sup 31}P NMR and infrared spectroscopic methods have been used to study the formation of small unilamellar vesicles by the pH-jump method. It is shown that increasing the pH of different lamellar phospholipid dispersions (phosphatidic acids and phosphatidylserines) induces a pH gradient. This pH gradient is estimated to be 4 {plus minus} 1 pH units, and its direction is such that the inner monolayer of the vesicles is at lower pH. There is spectroscopic evidence for tighter packing of the lipid hydrocarbon chains in the inner monolayer, probably due to the constraints imposed by the high curvature of the small vesicles formed. These results are discussed in terms of the driving force of the spontaneous vesiculation.

• OSTI ID: 7008906
• Journal Information: Biochemistry; (USA), Vol. 29:9; ISSN 0006-2960
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
CELL MEMBRANES
NUCLEAR MAGNETIC RESONANCE
PHOSPHOLIPIDS
INFRARED SPECTRA
NMR SPECTRA
PH VALUE
PHOSPHORUS 31
CELL CONSTITUENTS
ESTERS
ISOTOPES
LIGHT NUCLEI
LIPIDS
MAGNETIC RESONANCE
MEMBRANES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
PHOSPHORUS ISOTOPES
RESONANCE
SPECTRA
STABLE ISOTOPES
550601* - Medicine- Unsealed Radionuclides in Diagnostics