Inositol 4,5-diphosphate

Fig. 8-99. Gradient elution of inositol phosphate isomers. — Separator column IonPac AS5A eluent (A) water, (B) 0.15 mol/L NaOH gradient 8% B isocratically for 10 min, then 11% B isocratically for 3 min, then 52% B isocratically for 12 min, then 75% B isocratically for 35 min flow rate 1 mL/min detection suppressed conductivity injection volume 50 pL solute concentrations 30 mg/L inositol-2-phosphate (1), inositol-1-phosphate (2), inositol-4-phosphate (3), 10 mg/L inositol-1,4-diphosphate (4), inositol-2,4-diphosphate (5), inositol-4,5-diphosphate (6), inositol-1,3,4-triphosphate (7), and inositol-1,4,5-triphosphate (8).

Inositol L-form 1,2,3,5-Tetra-O-angeloyl, 1-28 -Inositol L-form 1,2,4,5-Tetra-O-angeloyl, 1-28 -Inositol l,2 3,4-Di-0-cyclohexylidene, 5-benzoyl, 1-30 wyo-Inositol 1,4-Diphosphate, 1-32 wyo-Inositol 1-0-p-D-Glucopyranoside, nona-Me, 1-32 wyo-Inositol hexakis(phosphate), 1-32 wyo-Inositol monoorthoformate, 1-32 wyo-Inositol 1,2,3,4,5-Pentaphosphate, 1-32 wyo-Inositol 1,2,3,4,6-Pentaphosphate, 1-32 myo-Inositol 1,2,3,5,6-Pentaphosphate, 1-32 myo-Inositol 1,2,4,5,6-Pentaphosphate, 1-32 myo-Inositol 1,3,4,5,6-Pentaphosphate, 1-32 myo-Inositol 2,3,4,5,6-Pentaphosphate, 1-32 myo-Inositol 1-Phosphate, ( ), 1-32 myo-Inositol 4-Phosphate, ( ), 1-32 myo-Inositol 1-Phosphate, 1-32 myo-Inositol 2-Phosphate, 1-32 myo-Inositol 3-Phosphate, 1-32 myo-Inositol 4-Phosphate, 1-32 myo-Inositol 5-Phosphate, 1-32 myo-Inositol 6-Phosphate, 1-32 myo-Inositol 3,4,5,6-Tetra-Ac, 1-32 myo-Inositol 2,3,5,6-Tetrabenzyl, 1-32 myo-Inositol 1,3,4,5-Tetraphosphate, 1-32 myo-Inositol 1,3,5,6-Tetraphosphate, 1-32 myo-Inositol 1,4,5,6-Tetraphosphate, 1-32 myo-Inositol 3,4,5,6-Tetraphosphate, 1-32 myo-Inositol 2,4,6-TVibenzyl, 1,3,5-0-methylidyne, 1-32 myo-Inositol 2,3,5-Tribenzyl, 1-32 myo-Inositol 1,2,3-Triphosphate, 1-32 myo-Inositol 1,3,4-Triphosphate, 1-32 myo-Inositol 1,4,5-Triphosphate, 1-32 myo-Inositol 1,4,6-Triphosphate, 1-32 myo-Inositol 2,4,5-Triphosphate, 1-32 myo -Inositol-1,2,6-triphosphate, 1-32 fl//o-Inositol, 1-27 i -Inositol, 1-28 /-Inositol, 1-28 cw-Inositol, 1-29 ep/-Inositol, 1-30 mwco-Inositol, 1-31... 

Oositol 1-monophosphate, (6) unknown, (7) carbonate, (8) sulfate, (9) unknown, (10) inositol-1,4-diphosphate, (11) orthophosphate, (12) inositol-4,5-diphosphate, (13) inositol-1,5,6-tri-Phosphate, (14) inositol-1,2,5,6-tetraphos-Phate, (15) inosltol-1,4,5-triphosphate, and (16) inositol-1,3,4,5-tetraphosphate. 

Mvo-inositol 1,4-diphosphate (38), the racemate of a metabolite of second messenger myo-inositol 1,4,5-triphosphate and its diphosphorothioate analogue (39) have been synthesised from f 1 -1 2.4 S-di-O-isopropylidene-mvo-inositol by way of phosphite intermediates. Similarly, (-mvo-inositol 1,3,4-triphosphate has been obtained from f W2.4.S-tri-O-benzyl-myo-inositol Phosphite chemistry was also employed in the preparation of diphosphorylated and diphosphonylated Lipid A monosaccharide analogues (40). Related Lipid A components are mentioned in Chapter 9. Methyl 3-deoxv-a-D-manno-oct-2-ulopyranosidonic acid 4-phosphate has been synthesised and its chemical stability studied. ... 

In addition to ATP and GTP, other phosphate metabolites that are found in the RBCs of species such as Amazon fishes include DPG, IP2 (inositol diphosphate), IPP, and IHP. In general the effects of these compounds on fish Hb functions decrease in the following order IHP, IPP, GTP, ATP, DPG. At this time, unfortunately, there is very little information on details of the evolution of these interesting Hb modulators. Why an air-breathing fish such as Arapaima should utilize IPP, while another air breather, a catfish (which uses its stomach as a gas exchange organ), stores DPG in its RBCs and still other species rely only upon NTPs, are issues that remain poorly or not at all understood (Val, 1996). 

As yeast contains only a single InsPg-kinase (mammals contain three isoforms), much of what we know regarding the functional roles of inositol diphosphates is the result of... 

York SJ, Armbruster BN, Greenwell P, Petes TD, York JD. Inositol diphosphate signaling regulates telomere length. J. Biol. Chem. 2005 280 4264 269. 

FIGURE 10.43 Adrenal glomerulosa cells were incubated in a medium of salts and other nutrients. Inositol was added to the medium. The inositol was radioactive to allow the researcher to determine if metabolism resulted in its incorporation into phospholipids or its modification by phosphorylation. Incubation of [ H]inositol with the cells resulted in its incorporation as phosphatidylpH]inositol diphosphate pH is called tritium). (Redrawn with permission from Balia et al, 1988.)... 

Liquid Chromatography. - Diasteriomeric phosphonodipeptides have been separated by ion exchange column chromatography.267 H.p.l.c. has been used for the analysis of a variety of biologically active phosphorus compounds, such as aminoacid phosphate esters,26 phosphinothrycin,269 inositol triphosphate,270 fructose diphosphate,271 pyridoxal phosphate,272 and ATP.273... 

Inositol triphosphate (IP3)-gated channels are also associated with membrane-bound receptors for hormones and neurotransmitters. In this case, binding of a given substance to its receptor causes activation of another membrane-bound protein, phospholipase C. This enzyme promotes hydrolysis of phosphatidylinositol 4,5-diphosphate (PIP2) to IP3. The IP3 then diffuses to the sarcoplasmic reticulum and opens its calcium channels to release Ca++ ions from this intracellular storage site. 

VASP, vasodilator stimulated phosphoprotein hsp27, heat shock protein hsp27 LASP, LIM and SH3 domain containing protein Tx, thromboxane IP3, inositol triphosphate ADP, adenosine 5 -diphosphate. Adapted from Refs. [44] and [116]. 

Afyo-inositol-4-phosphate Afyo-inositol-4,5-diphosphate... 

Cleavage of inositol-containing phospholipids by phospholipase C is of particular regulatory importance. Phospholipase C catalyzes the release of diacyl glycerol and inositol-l,4,5-triphosphate from phosphatidyl inositol-4,5-diphosphate, a phospholipid... 

ATP + 1-phosphatidyl-lD-myo-inositol-4-phosphate = ADP -I- 1-phosphatidyl-lo-myo-inositol 3,4-diphosphate... 

On hydrolysis of the phosphatides, myo-inositol monophosphate—and, from a brain phosphatide, a diphosphate—is obtained but, these products have, in most cases, not been adequately characterized, and it is not yet known whether all phospholipids contain the same myo-inositol phosphate. It has been shown169-170 that the phosphate obtained by hydrolysis of liver phosphatide171 or soybean phosphatide172 is a mixture of myo-inositol 1- and 2-phosphates. A myo-inositol phosphate, of unknown constitution, was isolated173 from liver without previous hydrolysis apparently it occurs in the free state. 

Fig. 1. A compact visual summary of the signaling of cytoplasmic/nuclear and cell surface receptors. ER, endoplasmic reticulum M, mitochondrion PIP2, phosphatidylinositol-4,5-diphosphate IP3, inositol triphosphate PK, protein kinase, second messenger.

Loewus, M.W., and Loewus, F.A., 1974, myo-inositol 1-phosphate synthase inhibition and control of uridine diphosphate-D-glucuronic acid biosynthesis. Plant Physiol. 54 367-371. 

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