Disease relevance of C01742

• Klebsiella pneumoniae is presently unique among bacterial species in its ability to metabolize not only sucrose but also its five linkage-isomeric alpha-d-glucosyl-d-fructoses: trehalulose, turanose, maltulose, leucrose, and palatinose [1].
• Non-cariogenicity of the disaccharide palatinose in experimental dental caries of rats [2].
• When Streptococcus mutans was successively subcultured in a broth medium containing 1% palatinose, the strains belonging to serotype a, d, or g did not ferment palatinose, whereas the strains belonging to serotype b, c, e, or f did ferment palatinose [2].
• Here we describe for the first time the cloning and characterization of the palatinose (pal) genes from Erwinia rhapontici [3].
• Structural and functional analysis of a putative gene cluster for palatinose transport on the linear chromosome of Agrobacterium tumefaciens MAFF301001 [4].

High impact information on C01742

• Like Mal61p, Agt1p is a high-affinity, maltose/proton symporter, but Mal61p is capable of transporting only maltose and turanose, while Agt1p transports these two alpha-glucosides as well as several others including isomaltose, alpha-methylglucoside, maltotriose, palatinose, trehalose and melezitose [5].
• The induction of VvHT1 expression by both Suc and palatinose was confirmed in the homologous grape berry cell culture [6].
• MAPK activity was found to be strongly activated by turanose, palatinose, and fluoro-Suc, but not by Suc and Glc [7].
• Enzyme kinetics revealed different effects of palatinose on Suc synthase and invertase activities, implicating palatinose as an allosteric effector leading to an inhibition of Suc synthase and (surprisingly) to an activation of invertase in vitro [8].
• The caries-inducing activity of palatinose (isomaltulose, alpha-D-glucopyranosyl-1,6-fructose) was examined in in vitro and in vivo experiments, comparing it with other carbohydrates [2].

Chemical compound and disease context of C01742

• To explore the potential of transgenic plants as alternative production facilities for palatinose, a chimeric sucrose isomerase gene from Erwinia rhapontici under control of a tuber-specific promoter was introduced into potato plants [9].
• 13-Week oral toxicity study with isomaltulose (Palatinose) in rats [10].

Biological context of C01742

• Specific-pathogen-free rats which had been infected with S. mutans 6715 and fed a diet containing 56% palatinose did not develop significant dental caries [2].
• Cloning and characterization of the gene cluster for palatinose metabolism from the phytopathogenic bacterium Erwinia rhapontici [3].
• Homology searches of the deduced amino acid sequences revealed that the proteins belong to a cluster of gene products putatively responsible for the metabolism of isomaltulose (palatinose; 6-O-alpha-d-glucopyranosyl-d-fructose) [11].
• The study suggest that palatinose administered parenterally is metabolized by tissues and expected to be used as a source of fluid and energy supply [12].
• Effect of a novel palatinose-based liquid balanced formula (MHN-01) on glucose and lipid metabolism in male Sprague-Dawley rats after short- and long-term ingestion [13].

Anatomical context of C01742

• On the other hand, the direct stimulatory effect of insulin release from pancreatic B-cell was not observed when the palatinose was infused into the isolated perfused rat pancreas [12].
• These results suggest that the process of hydrolysis is the rate limiting step in digestion-absorption process of palatinose, GPS and GPM in small intestine [14].
• GPS and GPM were hydrolyzed in mucosal homogenate as well as in brush border membranes of rat small intestine at a slower rate than the rate of hydrolysis of palatinose (30%) and sucrose (6-7%) [14].
• 2. Part of ingested hydrogenated palatinose arrived unsplit at the caecum of the rat and underwent fermentation there; excretion in feces and urine are neglegible in man and rat [15].

Associations of C01742 with other chemical compounds

• Sucrose isomerase catalyses the reversible conversion of sucrose into palatinose, which is not further metabolizable by plant cells [16].
• We herein investigated the effects of a novel, palatinose-based liquid diet (Inslow, Meiji Dairy Products, Tokyo, Japan) on postprandial plasma glucose and insulin levels and on the rate of substrate oxidation in 7 healthy men [17].
• 15 subjects refrained from toothbrushing during 3 test periods and rinsed 15 x daily for 4 d with 10 ml of: (1) 50% palatinose, (2) 37.5% palatinose + 12.5% xylitol, or (3) 50% xylitol [18].
• In contrast, M-G catalysed the hydrolysis of starch, amylose and maltose with a Km of 3.12 mM, 7.59 mM and 3.52 mM respectively, and had no action on sucrose or palatinose [19].

Gene context of C01742

• We identified a putative pal gene cluster (palR, palE, palF, palG, palK, palA, and palB) in the plant-tumorigenic bacterium Agrobacterium tumefaciens MAFF301001; by sequencing analyses, this cluster was found to be involved in palatinose transport, and its functional importance was revealed by mutational analyses [4].
• Insertion mutations in the palK and palE genes showed the necessity of these genes for bacterial growth and chemotaxis with palatinose as the carbon source, but no inhibition of tumorigenesis was observed [4].
• Molecular characterization of the alpha-glucosidase activity in Enterobacter sakazakii reveals the presence of a putative gene cluster for palatinose metabolism [11].

Analytical, diagnostic and therapeutic context of C01742

• Based on our results we conclude that plants can efficiently be used as bioreactors for the production of palatinose [20].
• 3. Growth and maintenance of rats demonstrated 20--40 percent diminished caloric utilisation of diets containing 34.5 percent hydrogenated palatinose whereas indirect calorimetry in man showed about 50 percent caloric deficit [15].
• Consequently, repeated ingestion of DFAIII for 12 days was as safe as palatinose ingestion, especially with respect to abdominal symptoms and blood test results, and its high resistance to enterobacterial fermentation in humans was not impaired [21].
• We investigated the effect of palatinose on mental concentration using the Uchida-Kraepelin psycho diagnostic test [22].
• The determination of the three-dimensional structure of SmuA will provide a basis for rational protein-engineering studies in order to optimize the industrial production of palatinose [23].

References