Disease relevance of N-Phospho-L-arginine

• AK activity was demonstrated in vivo by monitoring the decreases in PArg and ATP resonances during prolonged ischemia [1].
• Anoxia produced an expected decrease in peak intensities of ATP and arginine phosphate while the peak of intracellular Pi was enhanced and shifted to indicate intracellular acidification during anoxia [2].
• The extent of changes in arginine phosphate and inorganic phosphate was directly proportional to the magnitude of the imposed acidosis [3].

High impact information on N-Phospho-L-arginine

• The product of the AK enzyme, phosphoarginine (PArg), served as an MRS-visible reporter of AK expression [1].
• Differential up-regulation of Na+-Ca2+ exchange by phosphoarginine and ATP in dialysed squid axons [4].
• Arginine kinase catalyzes the reversible transphosphorylation between adenosine diphosphate (ADP) and phosphoarginine, which is involved in temporal and spatial adenosine triphosphate (ATP) buffering [5].
• Subjecting animals to acute thermal change at an average rate of 1 deg. h-1 led to significant Pi accumulation (equivalent to PLA breakdown) and decrements in the free energy of ATP hydrolysis (dG/dzeta) at both ends of the temperature window, starting at mean critical temperatures (Tc) of 7.0 and 26.8 degrees C, respectively [6].
• Previous studies have shown that arginine phosphate (AP) recovery in the anaerobic (light) fibers, which demonstrate a fiber size dependence on anaerobic processes following contraction, is too slow to be restricted by intracellular metabolite diffusive flux, in spite of the fiber's large size [7].

Chemical compound and disease context of N-Phospho-L-arginine

• Hypoxia alone induced no change in the adenylate energy charge (AEC), total adenylate (TAN), ATP/ADP ratio or in the equilibrium constant for adenylate kinase K'(ADEN), apparently due to protection of ATP levels by arginine phosphate [8].

Biological context of N-Phospho-L-arginine

• Muscular fatigue corresponds to a 60% breakdown of phosphoarginine, and a 45% increase of sugar phosphates [9].
• We have demonstrated that phosphoarginine supplies energy as a 'phosphagen' for ciliary beating in Paramecium caudatum, suggesting that phosphoarginine functions not only as a reservoir of energy but also as a transporter of energy in these continuously energy-consuming circumstances. http://www.biologists.com/JEB/movies/jeb3123.html[10]
• This non-invasive technique is ideal for examining cellular respiration since critical metabolite concentrations, including phosphoarginine ([PA]), inorganic phosphate ([P(i)]) and [ATP], and the arginine kinase (AK) rate constant, can be monitored in real time [11].
• Arginine kinase (AK) catalyzes the reversible phosphorylation of arginine by MgATP to form a high-energy compound phosphoarginine (Parg) and MgADP in forward reaction in invertebrates [12].
• Neither acclimation salinity nor salinity change had a significant effect on the concentrations of arginine phosphate, inorganic phosphate or ATP [13].

Anatomical context of N-Phospho-L-arginine

• Phosphoarginine, a structural analogue of PCr which possesses Ca(2+)-binding property similar to that of PCr did not exert any protective effect on ischemic myocardium [14].
• Mitochondria prepared from muscles of a crustacean, a fish and a bird have been shown oxidatively to synthesise phosphocreatine (crustacean) and phosphoarginine (fish and bird) provided they are supplied with the appropriate kinase and catalytic amounts of ATP [15].
• Mitochondria from heart, skeletal muscle and the liver of the rat have been shown to synthesise phosphoarginine through ATP if supplied with arginine and lobster arginine kinase [15].
• 2. In the hepatopancreas phosphoarginine was significantly higher on day 21 in the starved crayfish [16].
• The collagen contents of a selected group of animals have been determined and considered in relation to a hypothesis that animals which changed from phosphoarginine to other phosphagens had a selective advantage in converting arginine to proline for the synthesis of connective tissue [17].

Associations of N-Phospho-L-arginine with other chemical compounds

• The kinetic data support the proposal that arginine phosphate, not ATP or citrate, is the most likely regulator of adductor phosphofructokinase in vivo under aerobic, high tissue pH, conditions [18].
• The time evolution of the phosphometabolite concentrations reveals that the hydrolysis of phosphoarginine is a first-order reaction producing inorganic phosphate, whilst the adenosine triphosphate level remains constant for more than 10 h [19].
• Differential effects of arginine, glutamate and phosphoarginine on Ca(2+)-activation properties of muscle fibres from crayfish and rat [20].
• Studies on the apparent inhibition of the type-M pyruvate kinase from Carcinus maenas (the common shore crab) by phospho-L-arginine [proceedings] [21].
• Adenylate energy charge, arginine phosphate and ATPase activity in juvenile Homarus americanus during the molt cycle [22].

Gene context of N-Phospho-L-arginine

• 1. Further addition of protamine molecules leads to a precipitation of the protamine-DNA complexes for arginine-phosphate ratio > or = 1 [23].
• Arginine kinase, the enzyme responsible for phosphoarginine and ATP synthesis, also shows a differential activity in epimastigote and trypomastigote parasite stages [24].
• Muscle AEC did not change with molt stage, but levels of ATP (F = 8.050) and ADP (F = 4.130) were significantly higher in premolt (D3 pleopod stage 5.0-5.5) animals; while levels of arginine phosphate (F = 6.981) were significantly higher in post-molt animals [22].
• 2. Both forms were monomeric (mol. wt. approximately 42,000) and showed the same pH optimum (7.5-8.0) in the direction of phosphoarginine synthesis [25].

Analytical, diagnostic and therapeutic context of N-Phospho-L-arginine

• A rapid high-performance liquid chromatography method for the determination of phosphoarginine (PArg) in invertebrate tissue has been redeveloped and validated [26].
• The dissociation constant of magnesium arginine phosphate, determined by gel filtration, was 30.0 +/- 0.9 mM [27].

References