D-myo-inositol-1-phosphate

D-myo-inositol 1-phosphate <1> (<1> weak, above 0.1 mM, stimulates below... 

Trinquet, E. et al. 2006. D-myo-inositol 1-phosphate as a surrogate of D-myo-inositol 1,4,5-tris phosphate to monitor G protein-coupled receptor activation. Anal. Biochem. 358, 126-135. 

Eisenberg, F.J., 1967, d-myo inositol 1-phosphate as product of cyclization of glucose 6-phosphate and substrate for a specific phosphatase in rat testis. J. Biol. Chem. 242 1375-1382. 

Barnett, J.E., and Corina, D.L., 1968, The mechanism of glucose 6-phosphate-D-myo-inositol 1-phosphate cyclase of rat testis. The involvement of hydrogen atoms. Biochem. J. 108 125-129. 

Sherman, W.R., Leavitt, A.L., Honchar, M.P., Hallcher, L.M., Packman, P.M., and Phillips, B.E., 1981b, Evidence that lithium alters phosphoinositide metabolism Chronic administration elevates primarily D-myo-inositol-1-phosphate in cerebral cortex of the rat. J. Neurochem. 36 1947-1951. 

An analogue of phosphatidyl inositol 4,5-diphosphate has been prepared from chiral 1,4-di-O-benzyl-5,6-di-O-allyl-myo-inositol, and D-myo-inositol 1-phosphate, obtained from a resolved l,2 4,5-di-... 

The General myo-lnositol and scyllo-Inosamine Pathway. Two distinct cyclitol pathways, which we earlier called Ca (started by myo-inositolphos-phate synthase) and Cb (started by T-deoxy-i cy/to-inosose synthase), are used in the initiation of AGA pathways. Here we will describe the Ca route and the Cb pathway in the paragraph on NEOs (see Section 2.2.2.1.3). The cyclitol pathway in the biosynthetic pathways for STRs, but also for other AGAs such as SPCs, KAS, and FORs and also the mixed type antibiotic HYG-A (see Section 2.2.4.3.1), starts with the formation of myo-inositol in a two-step pathway (Ca) that is not encoded in the itrAtt-clusters. The first step in streptidine biosynthesis (and any other myo-inositol utilising pathway) is the formation of a myo-inositol monophosphate (D-myo-inositol-3-phosphate or L-myo-inositol-1-phosphate) via L-myo-inositol-1-phosphate synthase, which in actinomycetes... 

Formation of the Initial Cyclitol. The first steps of FOR production are the same as in the biosynthesis of STR in short, the first step in FOR biosynthesis is postulated to be the formation of a myo-inositol monophosphate (D-myo-inositol-3-phosphate or L-myo-inositol-1-phosphate) via the cellular l-myo-inositol-1-phosphate synthase as in the STR pathway (Ca pathway see Section 2.2.1.2). As in the itr-Att-clusters, no gene for this enzyme has been found in the/or-cluster. As a second step in FOR biosynthesis the dephosphorylation of D-myo-inositol-3-phosphate via an inositolmonophosphate phosphatase has to follow. A putative gene product with this activity is that of the ForA protein (cf. Tables 2.17 and 2.18). The cyclitol is postulated to be first converted via two enzymes, a cluster-encoded myo-inositol 3-dehydrogenase (ForG member of the GFO/IDH/MocA oxidoreductase family) and the L-glutamine icy//o-3-inosose 3-aminotransferase (ketocyclitol aminotransferase I ForS), to icy//o-inosamine (3-deoxy-3-amino- cy/to-mositol). 

This enzyme [EC 5.5.1.4] catalyzes the conversion of D-glucose 6-phosphate to iL-myo-inositol 1-phosphate. NAD+ is required as a cofactor. 

Also known as inositol-1,4-bisphosphate 1-phosphatase [EC 3.1.3.57], this enzyme catalyzes the hydrolysis of d-myo-inositol 1,4-bisphosphate to generate D-myo-inositol 4-phosphate and orthophosphate. This enzyme can also act on inositol 1,3,4-trisphosphate (forming inositol 3,4-bisphosphate). Inositol-1,4,5-trisphosphate 1-phos-... 

S ATP -I- 1-phosphatidyl-1 D-myo-inositol 3-phosphate <1> (<1>, poor substrate compared to 1-phosphatidyl-1 D-myo-inositol 5-phosphate [1]) (Reversibility <1> [1]) [1]... 

J. E. G. Barnett, A. Rasheed, and D. L. Corina, Partial reactions of D-glucose 6-phosphate-1-L-myo-inositol 1-phosphate cyclase, Biochem. J. 131 21 (1973). 

Miller et al. achieved selective functionalization of the enantiotopic hydroxyl groups of meso-inositols. In particular, they were able to convert myo-inositol 49 to either mono-phosphorylated D-myo-inositol-l-phosphate 50 or D-myo-inositol-3-phosphate mt-50 in high yield and with excellent ee (98%) (Scheme 13.25) [40, 41], This remarkable result was achieved by using the pentapeptides 51 or 52 as catalyst. These catalysts were identified from peptide libraries by a combinatorial approach. The peptides 51 and 52 are highly selective and complementary low-molecular-weight kinase mimics. It is also interesting to note that the opposite enantioselectivity of catalysts 51 and 52 could hardly have been predicted on the basis of the type and sequence of the amino acids involved. (Application of the Miller peptide catalysts to the kinetic resolution of racemic alcohols is discussed in Section 12.1.)... 

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. 

Jin, X., Foley, K.M., and Geiger, J.H., 2004, The structure of the lL-myo-inositol-1-phosphate synthase-NAD2+-deoxy-D-glucitol 6-(e)-vinylhomophosphonate complex demands a revision of the enzyme mechanism. J. Biol. Chem. 279 13889-13895. 

Keller, R., Brearley, C., Trethewey, R., and Muller-Rober, B., 1998, Reduced inositol content and altered morphology in transgenic potato plants inhibited for 1 D-myo-inositol 3-phosphate synthase. Plant J. 16 403 110. 

Inositol is synthesized by the same route in all cells. D-Glucose-6-phosphate (d-G-6-P) is converted to L-mvo-inositol-1 -phosphate (l-I- 1 -P), which can also be termed D-myo-inositol-3-phosphate. The L-I-l-P is then hydrolyzed to myoinositol by a relatively specific phosphatase. As we will see, enzymes that do these reactions in bacteria and archaea can have quite different characteristics from the eukaryotic enzymes. 

Loewus, M.W., 1977, Hydrogen isotope effects in the cyclization of D-glucose 6-phosphate by myo-inositol-1 -phosphate synthase. J. Biol. Chem. 252 7221-7223. 

Majumder, A.L., Johnson, M.D., and Henry, S.A., 1997, lL-myo-inositol-1 -phosphate synthase. Biochim. Biophys. Acta 1348 245-256. 

---