A New Preparative Synthesis of 1-D-6-O-(2-Amino-2-Deoxy-D-glycopyranosyl)-chiro-Inositol 1-Phosphate and 1,2-Cyclic Phosphate

Author(s):  
Manuel Martín-Lomas ◽  
María Flores-Mosquera ◽  
Noureddine Khiar
1980 ◽  
Vol 45 (2) ◽  
pp. 611-616 ◽  
Author(s):  
Antonina P. Kavunenko ◽  
Antonín Holý

Preparative synthesis of dinucleoside monophosphates, catalyzed by ribonuclease A, is described. Uridine 2',3' -cyclic phosphate was used as a donor, the acceptors being uridine (Ia), N3-methyl-uridine (Ib), 5-methyluridine (Ic), 6-methyluridine (Id), 3-(β-D-ribofuranosyl)uracil (IIa), 1-methyl-3-(β-D-ribofuranosyl)uracil (IIb), 6-azauridine (III) and 6-methyl-2'-deoxyuridine (IV). The obtained compounds of the type UpN (where N is the nucleoside moiety I-IV) were characterized by paper chromatography, electrophoresis and UV-spectra.


1972 ◽  
Vol 130 (1) ◽  
pp. 229-238 ◽  
Author(s):  
N. Clarke ◽  
R. M. C. Dawson

1. On subcellular fractionation of rat kidney homogenates by differential and density-gradient centrifugation, the bulk of the inositol 1:2-cyclic phosphate 2-phosphohydrolase activity remains with the alkaline phosphatase activity, suggesting localization in the brush borders of the proximal tubules. 2. Histochemical studies with a medium containing inositol 1:2-cyclic phosphate and Escherichia coli phosphomonoesterase show Gomori staining around the brush borders of the proximal tubules in the outer cortex only. 3. Serial sections across the kidney from cortex perimeter to papilla suggest that the inositol 1:2-cyclic phosphate 2-phosphohydrolase has a limited distribution along the proximal tubule of the nephron, probably being limited to the pars convoluta, whereas the alkaline phosphatase extends along the pars recta.


1987 ◽  
Vol 243 (1) ◽  
pp. 211-218 ◽  
Author(s):  
P T Hawkins ◽  
C P Berrie ◽  
A J Morris ◽  
C P Downes

We have employed a neutral-pH extraction technique to look for inositol 1,2-cyclic phosphate derivatives in [3H]inositol-labelled parotid gland slices stimulated with carbachol. The incubations were terminated by adding cold chloroform/methanol (1:2, v/v), the samples were dried under vacuum and inositol phosphates were extracted from the dried residues by phenol/chloroform/water partitioning. Water-soluble inositol metabolites were separated by h.p.l.c. at pH 3.7. 32P-labelled inositol phosphate standards (inositol 1-phosphate, inositol 1,2-cyclic phosphate, inositol 1,4,5-trisphosphate and inositol 1,2-cyclic 4,5-trisphosphate) were quantitively recovered through both extraction and chromatography steps. Treatment of inositol cyclic phosphate standards with 5% (w/v) HClO4 for 10 min prior to chromatography resulted in formation of the expected non-cyclic compounds. [3H]Inositol 1-phosphate and [3H]inositol 1,4,5-trisphosphate were both present in parotid gland slices and both increased during stimulation with 1 mM-carbachol. There was no evidence for significant quantities of [3H]inositol 1,2-cyclic phosphate or [3H]inositol 1,2-cyclic 4,5-trisphosphate in control or carbachol-stimulated glands. Parotid gland homogenates rapidly converted inositol 1,4,5-trisphosphate to inositol bisphosphate and inositol tetrakisphosphate, but metabolism of the inositol cyclic trisphosphate was much slower. The results suggest that inositol 1,4,5-trisphosphate, but not inositol 1,2-cyclic 4,5-trisphosphate, is the water-soluble product of muscarinic receptor-stimulated phospholipase C in rat parotid glands.


1987 ◽  
Vol 248 (1) ◽  
pp. 203-208 ◽  
Author(s):  
I M Bird ◽  
A D Smith ◽  
D Schulster

[3H]Inositol-prelabelled isolated rat adrenal glomerulosa cells were stimulated with 25 nM-AII ([Asp1, Ile5]-angiotensin II) in the presence of 10 mM-Li+, and the resulting inositol monophosphate isomers were separated successfully by using a recently developed h.p.l.c. methodology. Two major peaks of radioactivity were detected which showed the same retention characteristics on h.p.l.c. as inositol 4-phosphate and inositol 1-phosphate and which increased 5-fold and 8-fold respectively on stimulation with AII. In addition, a relatively small peak with the retention characteristics of inositol 1:2-cyclic phosphate was seen to undergo a 1.5-fold increase on stimulation. This was not considered sufficient to suggest that cyclic phosphoinositols were a major product of AII-stimulated phosphoinositide turnover. No peaks of radioactive material were detected in the regions expected for inositol 2-phosphate (an acid hydrolysis product of inositol 1:2-cyclic phosphate) or inositol 5-phosphate. These results establish the identity of the major inositol phosphate products in AII-stimulated glomerulosa cells and confirm and extend the previous observations of Balla, Baukal, Guillemette, Morgan & Catt [(1986) Proc. Natl. Acad. Sci. 83, 9323-9327].


1983 ◽  
Vol 212 (2) ◽  
pp. 473-482 ◽  
Author(s):  
M J Berridge ◽  
R M C Dawson ◽  
C P Downes ◽  
J P Heslop ◽  
R F Irvine

The formation of inositol phosphates in response to agonists was studied in brain slices, parotid gland fragments and in the insect salivary gland. The tissues were first incubated with [3H]inositol, which was incorporated into the phosphoinositides. All the tissues were found to contain glycerophosphoinositol, inositol 1-phosphate, inositol 1,4-bisphosphate and inositol 1,4,5-trisphosphate, which were identified by using anion-exchange and high-resolution anion-exchange chromatography, high-voltage paper ionophoresis and paper chromatography. There was no evidence for the existence of inositol 1:2-cyclic phosphate. A simple anion-exchange chromatographic method was developed for separating these inositol phosphates for quantitative analysis. Stimulation caused no change in the levels of glycerophosphoinositol in any of the tissues. The most prominent change concerned inositol 1,4-bisphosphate, which increased enormously in the insect salivary gland and parotid gland after stimulation with 5-hydroxytryptamine and carbachol respectively. Carbachol also induced a large increase in the level of inositol 1,4,5-trisphosphate in the parotid. Stimulation of brain slices with carbachol induced modest increase in the bis- and tris-phosphate. In all the tissues studied, there was a significant agonist-dependent increase in the level of inositol 1-phosphate. The latter may be derived from inositol 1,4-bisphosphate, because homogenates of the insect salivary gland contain a bisphosphatase in addition to a trisphosphatase. These results suggest that the earliest event in the stimulus-response pathway is the hydrolysis of polyphosphoinositides by a phosphodiesterase to yield inositol 1,4,5-trisphosphate and inositol 1,4-bisphosphate, which are subsequently hydrolysed to inositol 1-phosphate and inositol. The absence of inositol 1:2-cyclic phosphate could indicate that, at very short times after stimulation, phosphatidylinositol is not catabolized by its specific phosphodiesterase, or that any cyclic derivative liberated is rapidly hydrolysed by inositol 1:2-cyclic phosphate 2-phosphohydrolase.


1974 ◽  
Vol 142 (3) ◽  
pp. 591-597 ◽  
Author(s):  
David Allan ◽  
Robert H. Michell

Phosphatidylinositol breakdown by subcellular preparations of small lymphocytes from pig mesenteric lymph nodes was investigated. Activity was higher than in preparations from the tissues studied previously; it was recovered largely in the soluble fraction, which showed pH optima at both 5.4–5.6 and 7.0–7.3. As in other tissues, phosphatidylinositol cleavage produced 1,2-diacylglycerol and a mixture of myo-inositol 1:2-cyclic phosphate and myo-inositol 1-phosphate. It was stimulated by addition of CaCl2 and, less effectively, by MgCl2. On sucrose-density-gradient ultracentrifugation at pH7.0 two peaks of activity were observed (approx. sedimentation coefficients 8S and 10S); the activity profiles on the gradients were similar when assayed at pH7.0 and 5.5. Activity at pH7.0 (and 0.4mm-CaCl2) was decreased by agents, such as salts and lipophilic cations, which tend to neutralize the negative charge of phosphatidylinositol; at pH5.5 these agents slightly stimulated activity. It is suggested that the same enzyme(s) may be responsible for activity at both pH optima and that previous workers may have underestimated the pH7.0 activity because of the inhibitory influence of cations under the usual assay conditions.


1973 ◽  
Vol 134 (1) ◽  
pp. 59-67 ◽  
Author(s):  
R. M. C. Dawson ◽  
N. G. Clarke

1. The ability to hydrolyse various phosphodiesterase substrates was examined in subcellular fractions of rat kidney and in serial slices of the kidneys of mouse, rat, guinea pig and ox cut from the cortex perimeter inwards. 2. d-Inositol 1:2-cyclic phosphate 2-phosphohydrolase could be clearly distinguished from phosphodiesterases which hydrolyse 2′:3′- and 3′:5′-cyclic AMP and p-nitrophenyl thymidine 5′-phosphate (phosphodiesterase I). The hydrolysis of sn-glycero-3-phosphorylcholine showed a distribution identical with that of particle-bound d-inositol 1:2-cyclic phosphate 2-phosphodiesterase, but there was a 30-fold difference in the ratio of enzyme activities between the rat and guinea pig. 3. In rat and mouse kidney, d-inositol 1:2-cyclic phosphate 2-phosphohydrolase is virtually all membrane bound and in the outer cortex, whereas in guinea-pig kidney the enzyme is almost entirely soluble and located throughout the kidney tissue. Some properties of the soluble enzyme are described. 4. Distribution and histochemical studies indicated that in the rat and mouse, phosphodiesterase I is associated with the brush borders of the straight portion (pars recta) of the proximal tubule, whereas inositol 1:2-cyclic phosphate 2-phosphohydrolase and probably glycerylphosphorylcholine diesterase are associated with the brush borders of the convoluted part of the tubule (pars convoluta).


Sign in / Sign up

Export Citation Format

Share Document