Skip to main content
Biology LibreTexts

A5. Reactions of Lysine

  •  reacts with anhydride in a nucleophilic substitution reaction (acylation).
  • reacts reversibly with methylmaleic anhydride (also called citraconic anhydride) in a nucleophilic substitution reaction.
  • reacts with high specificity and yield toward ethylacetimidate in a nucleophilic substitution reaction (ethylacetimidate  is like ethylacetate only with a imido group replacing the carbonyl oxygen). Ethanol leaves as the amidino group forms. (has two N -i.e. din - attached to the C)

 

Figure:  LYSINE REACTIONS 2

  • reacts with O-methylisourea in a nucleophilic substitution reaction. with the expulsion of methanol to form a guanidino group (has 3 N attached to C, nidi)
  • reacts with fluorodintirobenzene (FDNB or Sanger's reagent) or trinitrobenzenesulfonate (TNBS, as we saw with the reaction with phosphatidylethanolamine) in a nucleophilic aromatic substitution reaction to form 2,4-DNP-lysine or TNB-lysine.
  • reacts with Dimethylaminonapthelenesulfonylchloride (Dansyl Chloride) in a nucleophilic substitution reaction.

Figure:  LYSINE REACTIONS 3

  • reacts with high specificity toward aldehydes to form imines (Schiff bases), which can be reduced with sodium borohydride or cyanoborohydride to form a secondary amine.