Lipid conjugation reactions

The reaction is carried out in 0.2 M triethanolamine, pH 8.2. DMS should be the limiting reagent in the reaction to avoid blocking all amines on both molecules with only one end of the cross-linker, thus eliminating any conjugation. The amounts of total lipid and protein in solution may have to be adjusted to optimize each conjugation reaction and avoid precipitation of protein or aggregation of liposomes. 

To make scVEGF-lipid conjugate, add mPEG-DSPE-maleimide directly to deprotection reaction to a final molar protein-to-lipidratio of 1 2. Residual DTT will not affect modification reaction. Incubate lipidation reaction mixture at room temperature for 1 h. 

Kidneys are able to carry out extensive oxidation, reduction hydrolysis and conjugation reactions. The attractive hypothesis that cephaloridine is metabolized prior to producing nephrotoxicity [92] was not substantiated by experimental data. However, pretreatment of rats with 60 mg/kg cobalt chloride decreased cephaloridine-induced lipid peroxidation in renal cortical slices [31]. These results suggest that prior to producing nephrotoxicity, cephaloridine is taken up into renal cells, where, with the involvement of cytochrome P-450, it induces peroxidation of cell membrane lipids. 

Starting from biotin-A/-hydroxysuccinate 75, the biotin—lipid conjugates 76a—c were prepared by reaction with aminoalcohols at room temperature in DMF. Then, the phosphonate prodrugs 77a—c were obtained after reaction with (S)-HPMPC 55 in the presence of N,N-diisopropyle-thylamine (DIEA) and benzotriazol-l-yl-oxytripyrrolidinophosphonium hexafluorophosphate (PyBOP) in DMF at 45 °C. 

Liposome surface glyco-functionalizations were generally performed via direct formulations of controlled ratios of lipids and synthetic or naturally-derived glycolipids or chemical conjugation reactions of sugar ligands onto the surface of preformed liposomes carrying terminal... 

In this chapter, we have examined the use of cells and enzymes to chemically transform lipids. We have had to be selective and have predominantly focused attention on the transformation of sterols and steroids. We first explained why these compounds were commercially important and why they only occur in low concentrations in natural systems. We pointed out that a very large number of reaction types are possible, but those which have found greatest use include stereospedfic hydroxylations, alcohol/ketone interconversion, hydrolysis, conjugation and isomerisation. 

The chemical adducts formed by reaction of aldehydes with lysine residues form highly immunogenic epitopes, and antibodies have been prepared specific for malondialdehyde- and 4-hydroxynonenal-conjugated LDL (Gonen et al., 1987 Yla-Herttuala et al., 1989 Jurgens et al., 1990). These antibodies cross-react with material in atherosclerotic lesions but not normal tissue, thus supporting the central role of lipid peroxidation in the patho nesis of atherosclerosis (Yla-Herttuala et al., 1989, 1991). 

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