Identification of Phenylalanine 3-Hydroxylase formeta-Tyrosine Biosynthesis

Phenylalanine Hydroxylase, Tyrosine Hydroxylase, and Tryptophan Hydroxylase

Phenylalanine-Tyrosine Biosynthesis in NEUROSPORA CRASSA.

IOCHEMICAL investigations of the phenylalanine-tyrosine specific portion of the aromatic pathmway reveal a reaction sequence depicted in Figure 1. Although the organisms studied use similar intermediates to accomplish phenylalanine and tyrosine synthesis, some important functional differences exist. Aerobacter aerogenes and Escherichia coli W possess two molecular forms of chorismate mutase sep...

Immunocytochemical Identification of Phenylalanine Hydroxylase and Albumin

Rhodamine-conjugated antibodies specific for phenylalanine hydroxylase and serum albumin were employed as cytochemical probes to identify these two proteins in H4 hepatoma cells and in isolated rat hepatocytes . Each fluorescent antibody stained the cells specifically and in a distinctive manner . In both cell types, albumin staining was discretely localized in cytoplasmic "bundles," whereas, p...

Phenylketonuric Tetrahymena: phenylalanine hydroxylase mutants and other tyrosine auxotrophs.

Nineteen tyrosine auxotrophs of the ciliated protozoan Tetrahymena thermophila have been isolated and biochemically examined. These mutants are defective in the conversion of phenylalanine to tyrosine; this is analogous to the defect that causes phenylketonuria in humans. After nitrosoguanidine mutagenesis and self-fertilization, progeny clones were screened for tyrosine auxotrophy and positive...

Liver phenylalanine hydroxylase activity in relation to blood concentrations of tyrosine and phenylalanine in the rat.

The plasma concentration of phenylalanine and tyrosine decreases in normal rats during the first few postnatal days; subsequently, the concentration of phenylalanine remains more or less constant, whereas that of tyrosine exhibits a high peak on day 13. The basal concentrations of the two amino acids were not altered by injections of thyroxine or cortisol, except in 13-day-old rats, when an inj...