in recent years considerable interest has been focused on the plasma amino acid patterns as a possible index of protein malnutrition, in children. thus a change in the ratio of non-essential to essential amino acids is considered to be significant in the development of protein malnutrition. the present paper reports a simplified and rapid chromatographic procedure for the determination of this ...

Our previous findings [Hazelton & Lang (1978) Fed. Proc. Fed. Am. Soc. Exp. Biol. 37(6), 2378 (abstr.)] demonstrated a senescence-specific decrease in glutathione (GSH) concentration in the yellow-fever mosquito Aedes aegypti (Louisville)]. As a possible mechanism for this change, GSH biosynthesis was investigated in adult mosquitoes of different ages through the life-span. Biosynthesis was mea...

1. A neurotoxic protein similar to erabutoxins a and b of Laticauda semifasciata was isolated in crystalline form from the venoms of Laticauda laticaudata and Laticauda colubrina. The name ;laticotoxin a' is proposed. 2. Laticotoxin a is homogeneous by CM-cellulose column chromatography, disc electrophoresis and ultracentrifugation and by terminal amino acid analyses. 3. Laticotoxin a consists ...

The beta-lactam antibiotic penicillin is produced as an end product by some filamentous fungi only. It is synthesized from the amino acid precursors L-alpha-aminoadipic acid, L-cysteine, and L-valine. Previous data suggested that certain amino acids play a role in the regulation of its biosynthesis. Therefore, in this study the effects of externally added amino acids on both Aspergillus (Emeric...

the development of green approaches for the biosynthesis of silver nanoparticles (agnps) is of prime significance in the field of nanotechnology research. a fast and eco-friendly protocol for the biosynthesis of extracellular agnps using culture supernatant (cs) from the fungus cunninghamella phaeospora was studied in this work. this cs was proved as a potential new source for the extracellular...

Buchnera aphidicola, the obligate symbiont of aphids, has an extremely reduced genome, of which about 10% is devoted to the biosynthesis of essential amino acids needed by its hosts. Most regulatory genes for these pathways are absent, raising the question of whether and how transcription of these genes responds to the major shifts in dietary amino acid content encountered by aphids. Using full...

The function of serine protease EpiP in epidermin biosynthesis was investigated. Epidermin is synthesized as a 52-amino-acid precursor peptide, EpiA, which is posttranslationally modified and processed to the mature 22-amino-acid peptide antibiotic. epiP was expressed in Staphylococcus carnosus with xylose-regulated expression vector pCX15. The cleavage of the unmodified EpiA precursor peptide ...

The hypothesis that amino acids act as modifiers of phospholipid biosynthesis was tested in renal cortical cells from normal rats. The rate of [14C]-choline incorporation into phospholipid in cortical slices was enhanced by the addition of lysine or arginine to the incubation medium, and reduced by phenylalanine, aspartic acid, or four other amino acids. Lysine and aspartic acid appeared to mod...

Aminoacyl-tRNA synthetases guard the fidelity of cognate amino acid incorporation during protein biosynthesis; for example, phenylalanyl-tRNA synthetase (PheRS) activates and transfers only Phe to its tRNA. Since we are interested in using a computational protocol to identify nonnatural amino acids that are incorporated by wild-type PheRS, it is critical to understand the fidelity of PheRS in b...