Efficacy of Methionine Peptides as Determined by Chick Bioassay

Abstract
Chick growth assays were used to evaluate the efficacy of poly-l-methionine and dl/ld methionylmethionine (a 50:50 mixture of d-Met-l-Met and l-Met-d-Met). The polypeptide possessed no bioefficacy whatever, probably due to its extreme insolubility. The dipeptide of methionine exhibited growth-promoting ability equal to that of dl-methionine itself.