Arginine-Reactive and Photoreactive Cross-linkers

The ability to direct conjugation or modification specifically through arginine residues using this chemistry has been exploited in the availability of the only photoreactive glyoxal derivative, APG. 

APG has been used to inhibit bovine heart lactic dehydrogenase, egg white lysozyme, horse liver alcohol dehydrogenase, and yeast alcohol dehydrogenase (Ngo etal., 1981), in cross-linking RNA—protein interactions in . coli ribosomes (Politz et al., 1981), and in identifying regions of brome mosaic virus coat protein chemically cross-linked in situ to viral RNA (Sgro et al., 1986). 

A convenient molecule from which to build trifunctionals is the amino acid L-lysine. Its three functional groups, a-carboxy, a-amino, and e-amino, can be derivatized independently to contain three arms. Each arm can be designed to terminate in a complexing group able to participate in a particular type of conjugation reaction. 

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