Biomaterial Database

The C-5 hydrogen isotope-effect in myo-inositol 1-phosphate synthase as evidence for the myo-inositol oxidation-pathway. 1980

M W Loewus, and F A Loewus

The hydrogen isotope-effect that occurs in vitro during myo-inositol1-phosphate synthase-catalyzed conversion of D-[5-3H]glucose 6-phosphate into myo[2-3H]inositol 1-phosphate has been used to compare the functional role of the nucleotide sugar oxidation-pathway with that of the myo-inositol oxidation-pathway in germinating lily pollen. Results reveal a significant difference between the 3H/14C ratios of glucosyl and galactosyluronic residues from pectinase-amyloglucosidase hydrolyzates of the 70% ethanol-insoluble fraction of D-[5-3H, 1-14C]glucose-labeled, germinating lily pollen. This isotope effect at C-5 of D-glucose that occurred during its conversion into D-galactosyluronic residues of pectic substance is not explained by loss of 3H when UDP-D-[5-3H, 1-14C]glucose is oxidized by UDP-D-glucose dehydrogenase from germinating lily pollen. The evidence obtained from this study favors a functional role for the myo-inositol oxidation-pathway during in vivo conversion of glucose into galactosyluronic residues of pectin in germinating lily pollen.

UI	MeSH Term	Description	Entries
D007296	Myo-Inositol-1-Phosphate Synthase	An enzyme that catalyzes the formation of myo-inositol-1-phosphate from glucose-6-phosphate in the presence of NAD. EC 5.5.1.4.	Cycloaldolase,Inositol Cyclase,Inositol-1-Phosphate Synthase,Cyclase, Inositol,Inositol 1 Phosphate Synthase,Myo Inositol 1 Phosphate Synthase,Synthase, Inositol-1-Phosphate,Synthase, Myo-Inositol-1-Phosphate
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D010944	Plants	Multicellular, eukaryotic life forms of kingdom Plantae. Plants acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations. It is a non-taxonomical term most often referring to LAND PLANTS. In broad sense it includes RHODOPHYTA and GLAUCOPHYTA along with VIRIDIPLANTAE.	Plant
D011058	Pollen	The fertilizing element of plants that contains the male GAMETOPHYTES.	Male Gametes, Plant,Male Gametophytes,Microspores, Plant,Plant Microspores,Pollen Grains,Gamete, Plant Male,Gametes, Plant Male,Gametophyte, Male,Gametophytes, Male,Grain, Pollen,Grains, Pollen,Male Gamete, Plant,Male Gametophyte,Microspore, Plant,Plant Male Gamete,Plant Male Gametes,Plant Microspore,Pollen Grain
D011865	Radioisotope Dilution Technique	Method for assessing flow through a system by injection of a known quantity of radionuclide into the system and monitoring its concentration over time at a specific point in the system. (From Dorland, 28th ed)	Radioisotope Dilution Technic,Dilution Technic, Radioisotope,Dilution Technics, Radioisotope,Dilution Technique, Radioisotope,Dilution Techniques, Radioisotope,Radioisotope Dilution Technics,Radioisotope Dilution Techniques,Technic, Radioisotope Dilution,Technics, Radioisotope Dilution,Technique, Radioisotope Dilution,Techniques, Radioisotope Dilution
D002238	Carbohydrate Epimerases	Enzymes that catalyze the epimerization of chiral centers within carbohydrates or their derivatives. EC 5.1.3.	Carbohydrate Isomerases,Epimerases, Carbohydrate,Isomerases, Carbohydrate
D002250	Carbon Radioisotopes	Unstable isotopes of carbon that decay or disintegrate emitting radiation. C atoms with atomic weights 10, 11, and 14-16 are radioactive carbon isotopes.	Radioisotopes, Carbon
D014316	Tritium	The radioactive isotope of hydrogen also known as hydrogen-3. It contains two NEUTRONS and one PROTON in its nucleus and decays to produce low energy BETA PARTICLES.	Hydrogen-3,Hydrogen 3