Cyanogen bromide activated agarose

Coupling of Protein to Cyanogen Bromide-Activated Agarose... 

If purchased, cyanogen bromide-activated agarose will be in a dried form in the presence of stabilizers and will require swelling and washing before use. The activated groups are liable to hydrolysis at alkaline pH and thus the swelling and washing is carried out at acid pH. 

Figure 7-5. Effect of pH on the amount of alanine covalently bound to cyanogen bromide activated agarose. [From P. Cu-atrecasas, J. Biol. Chem., 245 3059 (1970).]...

Axen R and Porath J. Preparation of cyanogen bromide-activated agarose gels. Nature 1966 210 367. 

Van Leemputten E and Horisberger M. Immobilization of enzymes on magnetic particles. Biotechnol. Bioeng. 1974 16 385-396. lost R, Miron T, and Wilchek M. The mode of adsorption of proteins to aliphatic and aromatic amines coupled to cyanogen bromide-activated agarose. Biochim. Biophys. Acta 1974 362 75-82. 

The most serious problem encoimtered with agarose is the formation of an unstable isourea function from the reaction of cyanogen bromide-activated agarose with primary amines. This isomea forms a positively charged derivative ... 

Until 1973 the ionogenic nature of cyanogen bromide-activated agarose was not known, and many early investigations using this method must be examined closely. Furthermore, it should be noted that cyanogen bromide is toxic and presents an explosion hazard when impure. 

The popularity of use of cyanogen bromide-activated agarose for the immobilization of enzymes, affinants, etc. has continued but further work on the mechanism of activity of the matrix has suggested that the derivative is an isourea rather than the heretofore assumed cyclic imidocarbonate. Since other references have claimed to have proved the existence of the cyclic imidocarbonate ring, the use of the term agarose cyclic imidocarbonate has been retained in this volume but readers should familiarize themselves with the underlying chemistry. - ... 

Covalent coupling of TBADH to cyanogen bromide-activated agarose and on Eu-pergit C was studied by Keinan et al., who reported 30% or 15% residual activity, re-... 

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