Affordable Access

Publisher Website

Adsorption of bovine serum albumin (BSA) onto lecithin studied by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy

Authors
Journal
International Journal of Pharmaceutics
0378-5173
Publisher
Elsevier
Publication Date
Volume
337
Identifiers
DOI: 10.1016/j.ijpharm.2006.12.021
Keywords
  • Atr-Ftir
  • Protein Adsorption
  • Phospholipid
  • Nacl And Cacl2
Disciplines
  • Biology
  • Physics

Abstract

Abstract The adsorption of bovine serum albumin (BSA) to lecithin was investigated by ATR-FTIR spectroscopy. Lecithin films were prepared by casting aliquots of 3.2 μg lecithin in methanol onto ZnSe ATR prisms. Surface morphology and the thickness of the films were investigated by laser scanning confocal electron microscopy and scanning electron microscopy and the thickness of the films used for adsorption studies was estimated to be 40 Å. The dependency of the C O peak area on the lecithin mass in the calibration curve confirms that the thickness of the film is below the penetration depth of the infrared evanescent wave. Size exclusion HPLC and fluorescence spectroscopy show that BSA conformation in up to 1 M NaCl and CaCl 2 solutions is similar to that in water with no aggregation or changes in protein conformation seen over 4 h. The kinetics of BSA adsorption on the lecithin film from water, NaCl and CaCl 2 solutions demonstrates that ions promote the protein adsorption. BSA bound more in the presence of NaCl compared to CaCl 2 at equivalent concentrations. The adsorption appeared greatest at a 0.1 M concentration for both NaCl and CaCl 2. The results are explained in terms of absorptive reactivity of BSA and lecithin surfaces upon salt addition.

There are no comments yet on this publication. Be the first to share your thoughts.