PURIFICATION AND CHARACTERIZATION OF β-(PYRAZOL-1-YL)-L-ALANINE SYNTHASE FROM CITRULLUS VULGARIS

Article abstract of DOI:10.1016/S0031-9422(00)82594-7

From seedlings of Citrullus vulgaris the enzyme β-(pyrazol-1-yl)-L-alanine synthase was purified 200-fold, when it showed electrophoretic homogeneity (MW 58000) and could be dissociated into identical subunits (MW 32000) each containing one molecule of pyridoxal 5'-phosphate.The K_m value was 2.5E-3 M for O-acetyl-L-serine and 7.4E-2 M for pyrazole.The enzyme did not catalyse the formation of related β-substituted alanines, such as mimosine and L-quisqualic acid, and significant differences were found between the β-(pyrazol-1-yl)-L-alanine synthase and β-substituted alanine synthases and cystein synthase from other sources.Key dex - Citrullus vulgaris; Cucurbitaceae; watermelon; β-(pyrazol-1-yl)-L-alanine synthase; enzyme purification; O-acetyl-L-serine; β-(pyrazol-1-yl)-L-alanine.