Sucrose is a natural product occurs widely in nature. In living organisms such as plants, sucrose phosphate synthase (SPS) is the key rate-limiting enzyme for sucrose synthesis. SPS catalyzes the synthesis of sucrose-6-phosphate, which is further hydrolyzed by sucrose phosphatase to form sucrose. Researches on SPS in recent decades have been focused on the determination of enzymatic activity of SPS, the identification of the inhibitors and activators of SPS, the covalent modification of SPS, the carbohydrate distribution in plants regulated by SPS, the mechanism for promoting plant growth by SPS, the sweetness of fruit controlled by SPS, and many others. A systematic review of these aspects as well as the crystal structure and catalytic mechanism of SPS are presented.
Carbohydrate Metabolism ; Glucosyltransferases/metabolism* ; Plants/metabolism* ; Sucrose

In anesthetized normocapnic and normotensive dogs, the effect of arterial hypoxemia on cerebral blood flow and oxidative carbohydrate metabolism was studied. The results are as follows: 1) The hypoxic vasodilatory effect on cerevral vessels is intact even at profound systemic hypoxemia(Pao2 30 torr) if Paco2 is controlled within normal limits. 2) CMRO2 did not significantly increase above the normal even during profound arterial hopoxemis, indicating that CMRO2 levels are poor indices of hypoxia. 3) A disporportinately high glycolysis at Pao2 of 50 torr suggested early cerebral metabolic changes which became more marked with further decrease in Pao2. 4) One hour after restitution of normoxia, however, carebral blood flow and metabolism manifested complete recovery. 6) It is concluded that a transient(20 minutes) profoun systemic arterial hypoxemia does not produce prolonged disorder of cerebral blood flow and oxidative carbohydrate metabolism provided that the cerebral perfusion pressure is kept normal.
Animals ; Anoxia* ; Carbohydrate Metabolism ; Cerebrovascular Circulation* ; Dogs ; Glycolysis ; Metabolism*

Papaya, which is mainly cultivated in the southeastern region of China, is one of the four famous fruits in Lingnan. It is favored by people because of its edible and medicinal value. Fructose-6-phosphate, 2-kinase/fructose-2, 6-bisphosphatase (F2KP) is a unique bifunctional enzyme with a kinase domain and an esterase domain that catalyzes the synthesis and degradation of fructose-2, 6-bisphosphate (Fru-2, 6-P₂), an important regulator of glucose metabolism in organisms. In order to study the function of the gene CpF2KP encoding the enzyme in papaya, it is particularly important to obtain the target protein. In this study, the coding sequence (CDS) of CpF2KP, with a full-length of 2 274 bp, was got from the papaya genome. The amplified sequence of full-length CDS was cloned into the vector PGEX-4T-1 which was double digested with EcoR I and BamH I. The amplified sequence was constructed into a prokaryotic expression vector by genetic recombination. After exploring the induction conditions, the results of SDS-PAGE showed that the size of the recombinant GST-CpF2KP protein was about 110 kDa. The optimum IPTG concentration and temperature for CpF2KP induction were 0.5 mmol/L and 28 ℃, respectively. The purified sin[A1] gle target protein was obtained after purifying the induced CpF2KP protein. In addition, the expression level of this gene was detected in different tissues, and showed that the gene was expressed at the highest level in seeds and the lowest in pulp. This study provides an important basis for further revealing the function of CpF2KP protein and studying the involved biological processes of this gene in papaya.
Humans ; Carica/genetics* ; Recombinant Proteins ; Carbohydrate Metabolism ; Cloning, Molecular ; China

Child ; Humans ; Carbohydrate Metabolism, Inborn Errors ; Microcephaly ; Psychomotor Disorders ; Seizures

Liver X receptors (LXRs) are members of the nuclear receptor superfamily and are activated by oxysterols and intermediates in the cholesterol synthetic pathway. The pivotal role of LXRs in the metabolic conversion of cholesterol to bile acids has been well established. Furthermore, insulin induces LXRa in hepatocytes, resulting in the suppression of key enzymes in gluconeogenesis, including phosphoenolpyruvate carboxykinase, glucose-6-phosphatase, and fructose-1, 6-bisphosphatase (FBPase). LXRs also play an important role in fatty acid metabolism by activating the sterol regulatory element-bing protein 1c gene (SREBP1c). This articles reviews the molecular mechanisms by which LXRs act to influence the lipid and carbohydrate metabolism.
Animals ; Carbohydrate Metabolism ; Humans ; Lipid Metabolism ; Liver X Receptors ; Orphan Nuclear Receptors ; physiology

Enzymatic conversion is very important to produce functional rare sugars, but the conversion rate of single enzymes is generally low. To increase the conversion rate, a dual-enzyme coupled reaction system was developed. Dual-enzyme coupled reaction system was constructed using D-psicose-3-epimerase (DPE) and L-rhamnose isomerase (L-RhI), and used to convert D-fructose to D-psicose and D-allose. The ratio of DPE and L-RhI was 1:10 (W/W), and the concentration of DPE was 0.05 mg/mL. The optimum temperature was 60 degrees C and pH was 9.0. When the concentration of D-fructose was 2%, the reaction reached its equilibrium after 10 h, and the yield of D-psicose and D-allose was 5.12 and 2.04 g/L, respectively. Using the dual-enzymes coupled system developed in the current study, we could obtain sugar syrup containing functional rare sugar from fructose-rich raw material, such as high fructose corn syrup.
Aldose-Ketose Isomerases ; metabolism ; Carbohydrate Epimerases ; metabolism ; Fructose ; chemistry ; Glucose ; chemistry ; Hydrogen-Ion Concentration ; Temperature

Polysaccharides with multiple biological activities are usually considered as one of the major bioactive compounds in Chinese medicines (CMs). At present, the development of drug and functional foods related to polysaccharides have attracted a great deal of attention due to their great potential effects and diverse action mechanisms. However, quality control of polysaccharides is the bottleneck and a challenge due to their complexity and chemical diversity. Actually, the bioactivities of polysaccharides are closely related to their molecular structures. In order to ensure their safety and efficacy, the development of novel approaches based on the molecular structures for the improvement of quality control of polysaccharides is significantly important. Therefore, in this article, the relationship between biological activities and chemical structures, as well as the action mechanisms of polysaccharides from CMs were summarized first. Furthermore, saccharide mapping, a novel strategy for quality control of bioactive polysaccharides from CMs, was introduced and the application and perspectives were also discussed.
Carbohydrate Sequence ; Drugs, Chinese Herbal ; chemistry ; Molecular Sequence Data ; Polysaccharides ; chemistry ; Quality Control

BACKGROUND: 1-8D gene is a member of human 1-8 interferon inducible gene family and was shown to be overexpressed in fresh colon cancer tissues. Three peptides 1-6, 3-5 and 3-7 derived from human 1-8D gene were shown to have immunogenicity against colon cancer. METHODS: To study tumor immunotherapy of three peptides we established an active immunization model using HHD mice. D(b-/-) x beta2 microglobulin (beta2 m) null mice transgenic for a chimeric HLA-A2.1/D(b-)beta2 m single chain (HHD mice) were challenged with B16/HHD/1-8D tumor cells and were immunized with irradiated peptide-loaded RMA- S/HHD/B7.1 transfectants. In therapy model tumor growth was retarded in HHD mice that were injected with 3-5 peptide-loaded RMA-S/HHD/B7.1. In survival test vaccination with 1-8D-derived peptide protects HHD mice from tumor progression after tumor challenge. RESULTS: These studies show that peptide 3-5 derived from 1-8D gene can be the most effective candidate for the vaccine of immunotherapy against colon cancer and highlight 1-8D gene as putative colon carcinoma associated antigens. CONCLUSION: We demonstrated that RMA-S/HHD/ B7.1 loaded with 1-8D peptides, especially 3-5, immunization generates potent antitumor immunity against tumor cells in HHD mice and designed active immunization as proper immunotherapeutic protocols.
Animals ; Antigens, Tumor-Associated, Carbohydrate ; Colon* ; Colonic Neoplasms* ; Humans ; Immunization ; Immunotherapy ; Interferons ; Mice* ; Peptides ; Vaccination*

Werniche's encephalopathy is clinically characterized by the acute onset of global confusion, ataxia, gaze paresis, and nystagmus. It result from a deficiency in thiamine, an essential coenzyme in intermediate carbohydrate metabolism. The prompt use of thiamine prevents progression of the disease and reverses those lesions that have not yet progressed to the point of fixed structural change. We experienced a case of Wemiches encephalopathy associated with hyperemesis gravidarum, which happens to the patient who are injected only dextrose without thiamine. Therefore, we emphasize the need of thiamine replacement in hyperemesis gravidarum.
Ataxia ; Carbohydrate Metabolism ; Female ; Glucose ; Humans ; Hyperemesis Gravidarum ; Paresis ; Pregnancy ; Thiamine

The ketogenic diet (KD) is an established, effective, nonpharmacologic treatment for children with pharmacoresistant epilepsy. Although the KD is the most well-established dietary therapy for epilepsy, it is too restrictive and is associated with serious complications; therefore, alternative lower-fat diets, including a modified Atkins diet and low-glycemic index diet, have been developed. Recent ongoing clinical evidence suggests that other dietary therapies have an efficacy almost comparable to that of the KD. In addition, a diet rich in polyunsaturated fatty acids appears to increase the efficacy of diet therapy and reduce the complications of a high-fat diet. Here, we review the systematic information about lower-fat diets and better-quality dietary therapies and the current clinical status of each of these dietary approaches.
Child ; Diet ; Diet, Carbohydrate-Restricted ; Diet, High-Fat ; Epilepsy ; Fatty Acids, Unsaturated ; Humans ; Ketogenic Diet