BETA-CYANOALANINE PRODUCT OF CYANIDE FIXATION AND INTERMEDIATE IN ASPARAGINE BIOSYNTHESIS IN CERTAIN SPECIES OF LATHYRUS AND VICIA

β-Cyanoalanine, in the form of γ-glutamyl-β-cyanoalanine, has been established as a major product of fixation of inorganic cyanide in Vicia sativa seedlings. In Lathyrus sylvestris W., in which asparagine is the chief product of cyanide fixation, β-cyanoalanine serves as an intermediate. It probably serves in this role also in L. odoratus and V. villosa judged by demonstrated conversions of cyanide and β-cyanoalanine into asparagine. Double labeling of nitrogen and carbon has shown cyanide to be incorporated into β-cyanoalanine as a unit with its carbon-nitrogen bond intact. In V. sativa, the β-cyanoalanine route to asparagine is not active. β-Cyanoalanine, like cyanide, accumulates as γ-glutamyl-β-cyanoalanine, and synthesis of asparagine from free aspartic acid is now enhanced. A number of other compounds, including asparagine, γ-glutamyl-β-cyanoalanine, formate, serine, valine, phenylalanine, tyrosine, and cystine, have been tested as precursors of β-cyanoalanine or asparagine. © 1969, American Chemical Society. All rights reserved.