Biomolecular Interactions

Langmuir monolayers of insoluble bioactive molecules can be used to study interactions of drugs, peptides, nucleic acids and other biomolecules that interact at the interface. For more information, see the biomembranes and lipids section.

Most biochemical reactions in nature take place at membranes composed of phospholipid bilayers on or inside cells. The membrane affects protein folding and creates specific microenvironments where the reactions take place. To understand and mimic real biological systems, it is essential to study these interactions in an environment that closely mimics natural conditions. Langmuir monolayers of membrane phospholipids have been veri­fied as excellent model systems for biological membranes.

With LB and LS dipping it is possible to create immobilized biomolecular sensors and catalysts where biomolecules are embedded on a lipid layer to stabilize sensor molecule and prevent its denaturation. This can enhance the lifetime and activity of the molecules being studied.

For more information, see:

Immobilized proteins used as sensors

Immobilization of alcohol dehydrogenase in phospholipid Langmuir-Blodgett films to detect ethanol

Luciano Caseli, Angelo C. Perinotto, Tapani Viitala, Valtencir Zucolotto, and Osvaldo N. Oliveira, Jr.

Langmuir (2009), 25, 3057-3061

Alcohol dehydrogenase (ADH) mixed in dimyristoylphosphatidic acid (DMPA) monolayer exhibited enhanced transfer and detection ability towards ethanol compared to pure ADH layers. Studies proved that the ADH structure remained unchanged over one month in the mixed monolayer under storage conditions. A sensor array deposited on gold electrodes could detect alcohol down to 10 ppb concentration.

For more details of the study please check the original publication.

Enhanced activity of horseradish peroxidase in Langmuir–Blodgett films of phospholipids

Thais F. Schmidt, Luciano Caseli, Tapani Viitala, Osvaldo N. Oliveira Jr.

Biochimica et Biophysica Acta 1778 (2008), 2291–2297

Horseradish peroxidase (HRP) was immobilized into Dipalmitoylphosphatidylglycerol (DPPG) supported layers by LB-technique. PM-IRRAS studies confirmed that the HRP inserted into the monolayer and was transferred onto a support without denaturation of the protein. HRP exhibited higher activity towards peroxides when incorporated into a monolayer than when in solution.

For more details of the study please check the original publication.