The formation and cleavage of lysinoalanine crosslinks.
Treatment of lysinoalanine (LAL) with methyl iodide at pH-values above 8 leads to cleavage to dehydroalanine (DHA) and Nepsilon-di- or/and trimethyllysine, as was shown by ultraviolet spectra and amino acid analysis. This reaction is due to methylation of the crosslinking NH group of LAL to the quaternary ammonium compound; nucleophilic beta-elimination follows. By this reaction, the epsilon-amino groups of polylysine and its copolymers can be methylated to form di- and/or trimetryl-lysine residues. Chemically modified polypeptides containing Nepsilon-dimethyllysine can be made in this way.
D000409:Alanine / Q000031:analogs & derivatives* / Q000032:analysis; D055598:Chemical Phenomena; D002621:Chemistry; D006863:Hydrogen-Ion Concentration; D007454:Iodides; D007633:Keratins; D007700:Kinetics; D008239:Lysine / Q000031:analogs & derivatives* / Q000032:analysis; D008745:Methylation; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature
D007454:Iodides; D007633:Keratins; D008239:Lysine; D000409:Alanine