The construction of chiral supramolecular systems with desirable handedness is of great importance in materials science, chemistry and biology. In their paper, Y. L. Zhao and co-workers show how achiral bipyridines could complex with L-phenylalanine derivatives to form unexpected right-handed helical nanostructures through the co-assembly of these simple molecular building blocks. This work ope...

Unnatural amino acid mutagenesis has been used to selectively substitute tyrosine 66 of green fluorescent protein (GFP) with five novel amino acids: p-amino-L-phenylalanine, p-methoxy-L-phenylalanine, p-iodo-L-phenylalanine, p-bromo-L-phenylalanine, and L-3-(2-naphthyl)alanine. The absorbance and emission maxima of the resulting mutant GFPs span the range from 375 to 435 nm and 428 to 498 nm, r...

An agar medium combining dulcitol fermentation, malonate utilization, and phenylalanine deamination was evaluated with 229 isolates representing 19 genera. All reactions agreed with those obtained on conventional media.

Enantioselective Michael addition of aldehydes to nitroalkenes was successfully carried out by asymmetric catalysis with L-phenylalanine lithium salt, giving gamma-nitroaldehydes in good yields with high enantioselectivity.

Phenylalanine hydroxylase has been obtained from rat liver in a form that is 85 to 95% pure. The enzyme exists as two electrophoretically distinguishable isozymes, each of which is capable of existing as a monomer (51,000 to 55,000 molecular weight), dimer (llO,OOO), and tetramer (210,000). The dimers of each isozyme will dissociate to the monomeric forms by dilution of the enzyme or by increas...

Tubular nanostructures are suggested to have a wide range of applications in nanotechnology. We report our observation of the self-assembly of a very short peptide, the Alzheimer's beta-amyloid diphenylalanine structural motif, into discrete and stiff nanotubes. Reduction of ionic silver within the nanotubes, followed by enzymatic degradation of the peptide backbone, resulted in the production ...

Phenylketonuria is caused by mutations in the enzyme phenylalanine hydroxylase gene, that can result in abnormal concentrations of phenylalanine on blood, resulting in metabolites that can cause brain damage. The treatment is based on dietary restriction of phenylalanine, and noncompliance with treatment may result in damage of the brain function. Brain abnormalities can be seen on magnetic res...

CLINICALCHEMISTRY,Vol. 25, No. 2, 1979 335 3. Woolf, L. I., Jakubovic, A., and ChanHenry, E., The non-enzymatichydroxylation of phenylalanine to tyrosine by 2-amino-4hydroxy-6,7-dimethyl-5,6,7,8-tetrahydropteridin. Biochem. J. 124, 569 (1971). 4. Ayling, J. E., Pierson, W. D., Al-Janabi, J. M., and Helfand, G. D., Kidney phenylalanine hydroxylase from man and rat. Comparison with the liver enzy...

A low molecular weight hydrogelator with a covalently appended imidazole moiety is reported. Capable of percolating water in the pH range of 6 to 8, it proves to be an efficient catalyst upon self-assembly, showing Michaelis-Menten type kinetics. Activities at different pH values correlated with dramatic structural changes were observed. It can hydrolyse p-nitrophenyl acetate (pNPA) as well as ...

N-Galactosyl aziridines were synthesized via BF3·OEt2 promoted addition of carbenes generated from diazocarbonyl compounds with O-pivaloylated β-D-galactosylimines in good yields and high diastereoselectivity. The ring-opening reactions with p-toluenethiol of the aziridines provided enantiometrically pure β-S-substituted phenylalanine derivatives in a highly regioselective manner.