Infrared reflection–absorption spectroscopy: Principles and applications to lipid–protein interaction in Langmuir films

• Published in: Biochimica et biophysica acta Vol. 1798; no. 4; pp. 788 - 800
• Main Authors: Mendelsohn, Richard, Mao, Guangru, Flach, Carol R.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.04.2010
• Subjects: Aqueous monolayers; Infrared spectroscopy; Langmuir films; Lipid conformation; Membrane Lipids - chemistry; Membrane Lipids - metabolism; Membrane Proteins - chemistry; Membrane Proteins - metabolism; Membranes, Artificial; Molecular Structure; Protein Binding; Protein secondary structure; Pulmonary surfactant; Spectrophotometry, Infrared - methods; Surface Properties; Water - chemistry; Infrared spectroscopy; Aqueous monolayers; Langmuir films; Protein secondary structure; Pulmonary surfactant; Lipid conformation
• ISSN: 0005-2736; 0006-3002; 1879-2642
• DOI: 10.1016/j.bbamem.2009.11.024

Infrared reflection–absorption spectroscopy (IRRAS) of lipid/protein monolayer films in situ at the air/water interface provides unique molecular structure and orientation information from the film constituents. The technique is thus well suited for studies of lipid/protein interaction in a physiologically relevant environment. Initially, the nature of the IRRAS experiment is described and the molecular structure information that may be obtained is recapitulated. Subsequently, several types of applications, including the determination of lipid chain conformation and tilt as well as elucidation of protein secondary structure are reviewed. The current article attempts to provide the reader with an understanding of the current capabilities of IRRAS instrumentation and the type of results that have been achieved to date from IRRAS studies of lipids, proteins, and lipid/protein films of progressively increasing complexity. Finally, possible extensions of the technology are briefly considered.