Risk Assessment of "Other Substances" – L-phenylalanine and DL-phenylalanine
نویسندگان
چکیده
منابع مشابه
The metabolism in vivo of dl-phenylalanine in thiamine deficiency.
It is well established that phenylalanine and tyrosine are incompletely metabolized in scorbutic guinea pigs (15-17) and by premature infants (9, 10). Closs and Fijlling (3) have reported that phenylpyruvic acid appeared in the urine of thia,mine-deficient rats when extra phenylalanine was fed. The evidence in support of the latter claim was not conclusive, but such a finding would not be incon...
متن کاملSynthesis of d‐ and l‐Phenylalanine Derivatives by Phenylalanine Ammonia Lyases: A Multienzymatic Cascade Process†
The synthesis of substituted d-phenylalanines in high yield and excellent optical purity, starting from inexpensive cinnamic acids, has been achieved with a novel one-pot approach by coupling phenylalanine ammonia lyase (PAL) amination with a chemoenzymatic deracemization (based on stereoselective oxidation and nonselective reduction). A simple high-throughput solid-phase screening method has a...
متن کاملTherapeutic implication of L-phenylalanine aggregation mechanism and its modulation by D-phenylalanine in phenylketonuria
Self-assembly of phenylalanine is linked to amyloid formation toxicity in phenylketonuria disease. We are demonstrating that L-phenylalanine self-assembles to amyloid fibrils at varying experimental conditions and transforms to a gel state at saturated concentration. Biophysical methods including nuclear magnetic resonance, resistance by alpha-phenylglycine to fibril formation and preference of...
متن کاملL-Phenylalanine inhibition of muscle pyruvate kinase.
The allosteric inhibition of M1-type pyruvate kinase from rabbit skeletal muscle by phenylalanine is reciprocally dependent on Mg2+ and phosphoenolpyruvate concentrations. At pH 8, phenylalanine acts as a competitive inhibitor with respect to Mg2+ and phosphoenolpyruvate, and vice versa. Phenylalanine introduces sigmoidicity into the dependence of the reaction velocity on [Mg2+]. In vitro kinet...
متن کاملMechanism of phenylalanine regulation of phenylalanine hydroxylase.
The mechanism of phenylalanine regulation of rat liver phenylalanine hydroxylase was studied. We show that phenylalanine "activates" phenylalanine hydroxylase, converting it from an inactive to active form, by binding at a true allosteric regulatory site. One phenylalanine molecule binds per enzyme subunit; it remains at this site during catalytic turnover and, while there, cannot be hydroxylat...
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ژورنال
عنوان ژورنال: European Journal of Nutrition & Food Safety
سال: 2020
ISSN: 2347-5641
DOI: 10.9734/ejnfs/2020/v12i330205