title: A yeast glycolipid biosurfactant, mannosylerythritol lipid, shows high binding affinity towards lectins on a self-assembled monolayer system.
abstract: Mannosylerythritol lipids (MEL), which are glycolipid biosurfactants secreted by the Pseudozyma yeasts, show not only excellent surface-active properties but also versatile biochemical actions including antitumor and cell-differentiation activities. In order to address the biochemical actions, interactions between MEL-A, the major component of MEL, and different lectins were investigated using the surface plasmon resonance spectroscopy. The monolayer of MEL-A showed high binding affinity to concanavalin A (ConA) and Maackia amurensis lectin-I (MAL-I). The observed affinity constants for ConA and MAL-I were estimated to be 9.48 +/- 1.31 x 10(6) and 3.13 +/- 0.274 x 10(6) M(-1), respectively; the value was comparable to that of Manalpha1-6(Manalpha1-3)Man, which is one of the most specific probe to ConA. Significantly, alpha-methyl-D-mannopyranoside (1 mM) exhibited no binding inhibition between MEL-A and ConA. MEL-A is thus likely to self-assemble to give a high affinity surface, where ConA binds to the hydrophilic headgroup in a different manner from that generally observed in lectin-saccharide interactions. The binding manner should be related with the biochemical actions of MEL toward mammalian cells via protein-carbohydrate interactions.
authors.affiliation: Research Institute for Innovation in Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Konishi
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Imura
authors.forename: Tokuma
authors.initials: T
authors.lastname: Fukuoka
authors.forename: Tomotake
authors.initials: T
authors.lastname: Morita
authors.forename: Dai
authors.initials: D
authors.lastname: Kitamoto
mesh_terms: D001665:Binding Sites; D006017:Glycolipids / Q000737:chemistry*; D037102:Lectins / Q000737:chemistry*; D008567:Membranes, Artificial; D046912:Multiprotein Complexes / Q000737:chemistry; D011485:Protein Binding; D013501:Surface-Active Agents / Q000737:chemistry*; D015003:Yeasts / Q000378:metabolism*
chemical_list: D006017:Glycolipids; D037102:Lectins; D008567:Membranes, Artificial; D046912:Multiprotein Complexes; D013501:Surface-Active Agents; C439671:mannosylerythritol lipid