Membrane Deformation by Neolectins with Engineered Glycolipid Binding Sites

Abstract

Lectins are glycan-binding proteins that are involved in the recognition of glycoconjugates at the cell surface. When binding to glycolipids, multivalent lectins can affect their distribution and alter membrane shapes. Neolectins have now been designed with controlled number and position of binding sites to decipher the role of multivalency on avidity to a glycosylated surface and on membrane dynamics of glycolipids. A monomeric hexavalent neolectin has been first engineered from a trimeric hexavalent bacterial lectin, From this neolectin template, 13 different neolectins with a valency ranging from 0 to 6 were designed, produced, and analyzed for their ability to bind fucose in solution, to attach to a glycosylated surface and to invaginate glycolipid-containing giant liposomes. Whereas the avidity only depends on the presence of at least two binding sites, the ability to bend and invaginate membranes critically depends on the distance between two adjacent binding sites.

Computational design of a symmetrical β-trefoil lectin with cancer cell binding activity

“…For example, a hexavalent β -propeller neolectin was designed to bind glycolipids, and it was found that at least two binding sites are required for avidity. The distance between two adjacent binding sites strongly affects the ability of the protein to bend and invaginate membranes 11 . Although lectins are well-known for their medical properties, many are too toxic to be of clinical use.…”

2-Hydroxy Fatty Acid Enantiomers of Gb 3 Impact Shiga Toxin Binding and Membrane Organization

“…Proteins such as Shiga and cholera toxin B subunits as well as capsid lectins from SV40 and norovirus with multivalent binding sites are capable of clustering glycosphingolipids, resulting in the formation of membrane invaginations (1)(2)(3)(4). The B subunit of Shiga toxin (STxB) produced by Shigaella dysenteriae can bind up to 15 molecules of the globoside Gb 3 , thereby driving curvature changes of cellular and artificial membranes (1,5).…”

Plasma membrane reorganization: A glycolipid gateway for microbes

“…Reducing the valency from six to three by engineering one of the two binding sites per monomer resulted in a trimeric trivalent lectin that lost the capacity to induce membrane invaginations in GUVs [94]. A further step forward to control the number and the position of each of the binding sites in order to decipher the role of multivalency on membrane dynamics of glycolipids was the design of neolectins [95,96]. Starting from the trimeric hexavalent bacterial lectin RSL, a monomeric hexavalent neolectin was engineered with similar functional properties by introducing appropriate linkers.…”