SMPB-Modified PE Lipid Derivatives

Succinimidyl-4-(p-maleimidophenyl)butyrate (SMPB, Chapter 5, Section 1.6), is a heterobifunctional crosslinking agent that has an amine-reactive NHS ester on one end and a sulfhydryl-reactive maleimide group on the other. Conjugates formed using SMPB are linked by stable amide and thioether bonds. 

Prepare a liposome suspension, containing MPB-PE, at a total lipid concentration of 5 mg/ ml in 0.05 M sodium phosphate, 0.15 M NaCl, pH 7.2. Activation of DPPE with SMPB is 

Mix the protein solution with the liposome suspension in equal volume amounts. 

React overnight at room temperature with stirring. Maintain an atmosphere of nitrogen over the reaction to prevent lipid oxidation. 

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