Title

Polymerization Of A Cysteinyl Peptidolipid Langmuir Film

Abstract

The surface pressure-area isotherm of a cysteinyl peptidolipid on a pure water subphase (pH 5.8) was compared with that on a water subphase saturated with oxygen and buffered with ammonium bicarbonate (pH 7.8). A reduction of the limiting molecular area was observed for the isotherm measured on the subphase saturated with oxygen. Hysteresis in the compression-decompression cycles of the Langmuir film was also observed. Taking into consideration the chemical structure of the peptidolipid, we rationalized that the free sulfhydryl groups of the peptidolipid were oxidized in the presence of oxygen in the alkaline subphase to form intermolecular disulfide bonds at the air-water interface. The surface topography of the peptidolipid Langmuir film was observed by epi-fluorescence microscopy and the Langmuir-Blodgett film by environmental scanning electron microscopy (ESEM). The micrographs showed evidence of the polymerization of the cysteinyl peptidolipid at the air-water interface. Furthermore, the XPS spectra of the Langmuir-Blodgett films also proved the existence of disulfide bonds. The control peptidolipid C 18-Ser-Gly-Ser-OH showed identical surface pressure-area isotherms in the presence or absence of an oxygen-saturated subphase. © 2006 American Chemical Society.

Publication Date

1-3-2006

Publication Title

Langmuir

Volume

22

Issue

1

Number of Pages

181-186

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1021/la0527700

Socpus ID

30344470492 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/30344470492

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