Maleimide conjugation

Figure 18.9 NHS-PEG4-maleimide conjugation reactions are carried out in two steps involving modification of an amine-containing molecule with the NHS ester end with subsequent coupling of the maleimide end with a thiol-containing molecule.

Immobilization of Maleimide-Conjugated Carbohydrates on Thiol-coated Class Slides... 

By means of one of these synthons, 4-(di-tert-butyl[ F]fluorosilyl)benzenethiol (Si[ F]FASH), prepared by isotopic exchange in 40-60% radiochemical yield and subsequent coupling to a maleimide conjugate of serum albumin, an overall radiochemical yield of 12% was obtained within in overall synthesis time of 20-30 min (Wangler et al. 2009b). 

Kawasaki, Y. Mihashi, K. Tanaka, H. Ohnuma, H. Fluorescence study of N-(3-pyrene)maleimide conjugated to rabbit skeletal F-actin and plasmodium actin polymers. Biochim. Biophys. Acta, Protein Struct. 1976,446,166-178. 

Liburdy, R. P. Rabbit immunoglobulin-N-(3-pyrene)-maleimide conjugate for fluorescent immunoassay. U.S. Patent 4207075,1980. 

Liburdy, R. P. Antibody induced fluorescence enhancement of an N-(3-pyrene)maleimide conjugate of rabbit anti-human immunoglobulin G quantitation of human IgG. J. Immunol. Methods 1979,28, 233-242. 

Pyridinium p-toluenesulfonylmethylide 91 has been used as a formyl anion equivalent for conjugate addition to N-substituted maleimides to give the enol ethers 92, which were readily deprotected to give the aldehydes 93 (80TL705). 

The aqueous Diels-Alder reaction has also been used for bioconjugate studies. A Diels-Alder reaction of diene oligonucleotides with maleimide dieneophiles was used to prepare oligonucleotide conjugates in aqueous media under mild conditions (Eq. 12.39).102 A Diels-Alder-type cycloaddition of an electronically matched pair of saccharide-linked conjugated dienes and a dienophile-equipped protein was the... 

Figure 1.88 The maleimide group of BMPA reacts with a thiol-containing molecule to result in a modification having a terminal carboxylate group. Amine-containing molecules then can be conjugated to the carboxylate using a carbodiimide reaction with EDC.

Figure 5.4 SMCC reacts with amine-containing molecules to form stable amide bonds. Its maleimide end then may be conjugated to a sulfhydryl-containing compound to create a thioether linkage.

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