7-azatryptophan and 3-fluorophenylalanine

Amino acid-requiring mutants capable of producing derepressed levels of aspartate transcarbamylase (carbamoylphosphate:L-aspartate carbamoyltransferase, EC 2.1.3.2) were obtained and used for the incorporation in this enzyme of eight different amino acid analogs. These amino acid replacements enabled the biosynthesis of a series of modified aspartate transcarbamylases altered in their catalytic or regulatory properties. The enzyme in which phenylalanine was rereplaced by 2-fluorophenylalanine was purified to homogeneity and appeared to have the same specific activity as normal asparate transcarbamylase but lacking both homotropic and heterotropic interactions.

Topics: Alanine; Amino Acids; Aspartate Carbamoyltransferase; Escherichia coli; Ethionine; Macromolecular Substances; Methylhistidines; p-Fluorophenylalanine; Phenylalanine; Triazoles; Tryptophan