THE ISOLATION OF LANTHIONINE FROM HUMAN HAIR, CHICKEN FEATHERS, AND LACTALBUMIN

Abstract

In a recent publication1 the authors described the isolation from wool of a new thio ether diamino acid, lanthionine, HOOC--CH(NH2).CH2. S .CH2. CH(NH2).COOH.The wool was first boiled for 1 hour with 2 per cent Na2C03 solution and the treated fiber was then hydrolyzed with 20 per cent HCl.The isolation of this amino acid raised the question whether other proteins than wool would yield lanthionine under similar treatment.We are now able to report that we have isolated lanthionine not only from the keratins, human hair and chicken feathers, but also from lactalbumin by following the same procedure as was used in the case of wool.It therefore seems probable that lanthionine may be similarly obtained from most proteins which yield cystine on acid hydrolysis.Another question of interest which presented itself was whether the reaction during pretreatment of the proteins with Na&03 represented a general alkali effect or was due to some influence peculiar to Na2C03.That it was due to alkali effect was shown by the isolation of lanthionine from wool that had been boiled for 1 hour with 0.1 N NaOH or with 2 per cent Na&3 previous to acid hydrolysis.It is of interest to note, however, that when higher concentrations of alkali were used, for example N NaOH solution, all the wool was dispersed and hydrolysis of the products yielded cystine instead of lanthionine.