Studies on the interaction between linamarin and human serum albumin

Abstract

Human serum albumin (HSA) is a protein which makes up to 60% of the human plasma and as such is the most common protein in circulation. The protein is synthetized in the liver and possesses an array of functions, the main function being to reversibly bind a huge number of compounds thereby acting as a transporter. The binding increases the compounds solubility and helps in its distribution, except when the affinity is very high in which case larger dosses are needed to achieve the desired effect.

Linamarin (2-β-D-glucopyranosyloxy-2-methylpropanenitrile) is a cyanogenic glucoside found in Cassava, Manihot esculenta Crantz, a plant widely used as a food source in many developing countries for its nutritional values and its ability to endure harsh conditions. Upon ingestion it undergoes hydrolysis by a type of β-glucosidase called linamarase, produced by intestinal bacteria. The reaction yields glucose and acetonecyanohydrin, which later deteriorates into acetone and hydrogen cyanide. Since HCN is toxic to normal cells and the fact that these cells do not possess the gene for linamarase but has been discovered on some types of cancer cells, linamarin has been researched as a potential antitumor therapy. In the present study, fluorescence spectroscopy and molecular simulation were explored to study the interaction between linamarin and human serum albumin. To identify the binding site of linamarin on HSA, the displacement experiments were carried out using the site probes warfarin (site I) and ibuprofen (site II) as specific markers for distinct binding sites.