Efficient Synthesis of Methanesulphonate-Derived Lipid Chains for Attachment of Proteins to Lipid Membranes
作者:Matthew R. Hicks、Atvinder K. Rullay、Rosa Pedrido、David H. Crout、Teresa J. T. Pinheiro
DOI:10.1080/00397910802213794
日期:2008.10.22
We have developed an easy and flexible synthetic methodology to obtain lipid chains containing methanothiosulfonate terminal groups with the aim to attach them to natural proteins as functional groups. There are many proteins found in nature that are modified by lipids, and this is a key part of their function. For example, the prion protein is attached to the plasma membrane via a glycosylphosphatidylinositol (GPI) anchor, and this protein is thought to be the causative agent in diseases such as bovine spongiform encephalopathy (BSE; mad cow disease) and the human equivalent Creutzfeldt-Jakob disease. However, production of large amounts of protein in bacteria results in proteins that lack these lipid modifications. The lipid chains containing methanothiosulfonate terminal groups that we have synthesized here can be attached to these proteins through the thiol contained in the side chain of the cysteine residue, which can be incorporated into the protein sequence at the desired position.
Carbohydrate–protein interactions at interfaces: synthesis of thiolactosyl glycolipids and design of a working model for surface plasmon resonance
作者:Peter Critchley、M. Nicolas Willand、Atvinder K. Rullay、David H. G. Crout
DOI:10.1039/b210672h
日期:2003.3.13
Thiolactosyl lipids designed for carbohydrate-protein binding studies have been synthesised. One representative was selected for binding studies with a plant lectin RCA120, the agglutinin from Ricinus communis. The interactions were measured quantitatively in real time using a BIAcore surface plasmon resonance instrument. Removal of much of the galactose from the thiolactosyl lipid in situ with β-galactosidase showed that the lectin binding was highly specific. A dissociation constant KD
= 8.77 à 10â8 M was measured for 1-2-[2-(2-[β-D-galactopyranosyl-(1 â 4)-1-thio-β-D-glucopyranosyl]ethoxy)ethoxy]ethoxy}octadecane 30 which is four orders of magnitude greater than that determined for binding to lactose in solution. A concentration of lactose of >80 mM was required to block the lectin binding to thiolactosyl lipid in a neomembrane.