We investigated the composition of free amino acids in walnut (Juglans regia L.) seeds (embryo and cotyledons). We also examined xylem transport of free amino acids in young seedlings grown in the absence of external nutrients. A relatively high concentration of free alanine was found in seed tissue, whereas a relatively high concentration of citrulline was detected in young seedlings. Citrulli...

The study of the regulation of the arginine biosynthesis in Chlumydomonas [ 1, 21 is complicated by the degradation of arginine. As we reported earlier [3], the first enzyme of the catabolic pathway is arginine deiminase (L-arginine imino hydrolase, EC 3.5.3.6.). This enzyme causes the breakdown of arginine to citrulline and ammonia. Citrulline is then further degraded. Two pathways for the deg...

Producers of fresh fruits and vegetables face increasing production costs and international market competition. Growers who can offer high-quality watermelons [Citrullus lanatus (Thumb.) Matsum. & Nakai] that are also highly nutritious will have better market opportunities. To accomplish that, germplasm must be identified that has enhanced phytonutrient levels. Surprisingly, there is little inf...

Brain NO (nitric oxide) synthase contains FAD, FMN, heme, and tetrahydrobiopterin as prosthetic groups and represents a multi-functional oxidoreductase catalyzing oxidation of L-arginine to NO and L-citrulline, formation of H2O2, and reduction of cytochrome c. We show that substrate analogues and inhibitors interacting with the heme block both the reductive activation of oxygen and the oxidatio...

Consuming carbohydrate- and antioxidant-rich fruits during exercise as a means of supporting and enhancing both performance and health is of interest to endurance athletes. Watermelon (WM) contains carbohydrate, lycopene, l-citrulline, and l-arginine. WM may support exercise performance, augment antioxidant capacity, and act as a countermeasure to exercise-induced inflammation and innate immune...

BACKGROUND AND PURPOSE final sigma-Receptor ligands ameliorate ischemic neuronal injury and modulate neuronal responses to N-methyl-D-aspartate (NMDA) receptor stimulation. Because NMDA-evoked synthesis of nitric oxide (NO) may play an important role in excitotoxic-mediated injury, we tested the hypothesis that final sigma-receptor ligands attenuate basal and NMDA-evoked NO production in the st...

OBJECTIVE We examined the effects of aspirin on basal and beta-adrenoceptor (beta-AR)-mediated nitric oxide synthase (NOS) activity in normal platelets. METHODS NOS activity was determined from the conversion of L-[3H]arginine to L-[3H]citrulline, both basally and following beta-AR stimulation, in platelets from healthy human subjects following both short- and long-term aspirin administration...

BACKGROUND Nitric oxide (NO) is a cell messenger with multiple actions in different biological systems, implicated in the control of follicle and oocyte function. NO is formed from L-arginine by isoforms of nitric oxide synthase (NOS) via NG-hydroxy-L-arginine, with L-citrulline as a byproduct. This study aimed to show how modulation of NO by manipulating NOS substrates would affect mouse folli...

Highly luminescent, manganese doped, zinc sulphide (ZnS:Mn) nanocrystals biofunctionalized with chitosan and various aminoacids such as L-citrulline, L-lysine, L-arginine, L-serine, L-histidine and glycine were synthesized by chemical capping co-precipitation method at room temperature, which is a simple and cost effective technique. The synthesized nanocrystals were structurally characterized ...