The biochemical lesion associated with mental deficiency in phenylpyruvic oligophrenia is a failure of an enzyme system in these individuals to hydroxylate phenylalanine to tyrosine (Jervis, 1953). The biochemical ramifications of this single genetic loss are vast, but as yet no direct evidence has been forthcoming which specifically relates the appearance of the biochemical abnormality to the ...

The phenylalanine biosynthetic pathway in the yeast Rhodotorula glutinis was examined, and the following results were obtained. (i) 3-Deoxy-D-arabinoheptulosonate-7-phosphate (DAHP) synthase in crude extracts was partially inhibited by tyrosine, tryptophan, or phenylalanine. In the presence of all three aromatic amino acids an additive pattern of enzyme inhibition was observed, suggesting the e...

The bifunctional P protein (chorismate mutase : prephenate dehydratase) from Acinetobacter calcoaceticus has been purified. It was homogeneous in polyacrylamide gels and was more than 95% pure on the basis of the immunostaining of purified P protein with the antibodies raised against the P protein. The native enzyme is a homodimer ( M , = 91 000) composed of 45-kDa subunits. A twofold increase ...

The transporter protein Large-neutral Amino Acid Transporter 1 (LAT-1, SLC7A5) is responsible for transporting amino acids such as tyrosine and phenylalanine as well as thyroid hormones, and it has been exploited as a drug delivery mechanism. Recently its role in cancer has become increasingly appreciated, as it has been found to be up-regulated in many different tumor types, and its expression...

The conversion of prephenic acid to tyrosine can occur by two different routes: (a) oxidative decarboxylation (prephenate dehydrogenase) followed by transamination (aromatic aminotransferase); (b) transamination of prephenate forming the non-aromatic amino acid arogenic acid (prephenate aminotransferase) followed by oxidative decarboxylation (arogenate dehydrogenase). High activity of arogenate...

Despite being an anabolic hormone in skeletal muscle, insulin's anticatabolic mechanism in humans remains controversial, with contradictory reports showing either stimulation of protein synthesis (PS) or inhibition of protein breakdown (PB) by insulin. Earlier measurements of muscle PS and PB in humans have relied on different surrogate measures of aminoacyl-tRNA and intracellular pools. We rep...

The purpose of the current research is investigating the phenylalanine removal by using magnetic nanoparticles (Fe3O4) from water samples. The effect of pH, contact time and phenylalanine concentration on phenylalanine adsorption efficiency by magnetite nanoparticles are studied in a batch system. Transmission electron microscopy (TEM), X-ray Diffraction Patterns (XRD) and...

The facts described by Happold &'Hoyle [1936] and Evans et al. [1941] can be concisely stated as follows: (1) In a complex medium (e.g. bouillon, casein-digest, etc.) in which the presence of glucose in sufficient amount inhibits completely the production of indole by B. coli, the complete tryptophanase system is absent from the cells. (2) With a simple salt medium as used by Fildes, glucose on...

AND LILLIAN K. SCHNEIDER..................................... 181 The Consequences of Mutation during the Growth of Biochemical Mutants of Escherichia coli. III. The Inhibition of Histidine-independent Bacteria by Histidineless I3acteria in Aerated Cultures. FRANCIS ,J. RYAN AND LILLIAN K. SCHUCHARDT ................................... 191 The Consequences of Mutation during the Growth of Bioch...

Carboxypeptidase T (CPT; EC 3.4.17.18) from Thermoactinomyces vulgaris is a distant homolog of the highly specific pancreatic carboxypeptidase B; but has broad substrate specificity; source which remains unclear. A previous study structural bases specificity CPT using stable sulfamoyl analogs transition state elimination leucine; phenylalanine; arginine; and glutamic acid; showed that binding C...