Disease relevance of Maltoheptaose

• Moreover, RafY permits diffusion of the tetrasaccharide stachyose and of maltodextrins up to maltoheptaose through the outer membrane of E. coli [1].
• The maltodextrin (maltose through maltoheptaose) acceptor reactions of two Streptococcus mutans 6715 glucosyltransferases (GTF-I and GTF-S) were studied [2].

High impact information on Maltoheptaose

• Additional soaking of these crystals with maltoheptaose resulted in replacement of Tris in the active site with maltoheptaose, allowing the mapping of the -1 to +5 binding subsites [3].
• The 22-residue deletion mutant (Nd22) had overall kinetic properties similar to the WT enzyme, except that Nd22 was a better substrate for the protein kinase and the rate of phosphorylation was unaffected by maltoheptaose [4].
• We have determined the 2.0 and 2.5 A X-ray structures of E257A/D229A CGTase in complex with maltoheptaose and maltohexaose [5].
• D-enzyme was partially purified from wheat endosperm and shown to exhibit disproportionating activity in vitro by cleaving maltotriose to produce glucose as well as being able to use maltoheptaose as the donor for the addition of glucans to the outer chains of glycogen and amylopectin [6].
• SusC protein proved to be essential for utilization not only of starch but also of intermediate-sized maltooligosaccharides (maltose to maltoheptaose) [7].

Chemical compound and disease context of Maltoheptaose

• 1. Escherichia coli can accumulate 14C-labelled (alpha 1 leads to 4)-linked D-glucose oligomers up to maltoheptaose [8].
• The inability to transport dextrins larger than maltoheptaose is, therefore, due to the inability of E. coli to transfer large substrates from the binding protein to the cytoplasm and not to lack of access through the outer membrane [8].

Biological context of Maltoheptaose

• Increases in activation energy of maltoheptaose hydrolysis in most of the mutant glucoamylases suggested cleavage of individual hydrogen bonds in enzyme-substrate complexes [9].
• The maltoheptaose derivatives were attached by reductive amination or hydrosilation to amino- or SiH-terminated polystyrene (synthesized by anionic polymerization), respectively [10].

Anatomical context of Maltoheptaose

• The derivatization methodology was tested on maltoheptaose and three different human milk oligosaccharides [11].

Associations of Maltoheptaose with other chemical compounds

• The rate parameters measured for the hydrolysis of starch and various chain length malto-oligosaccharides shows high catalytic efficiency, calculated by the relationship V(cat)/K(m), for malto-oligosaccharides, such as maltotriose (873 mM(-1) min(-1)), or maltoheptose (698 mM(-1) min(-1)) [12].
• The The Glu180----Gln mutation drastically increased the KM and moderately decreased the kcat with maltose and maltoheptaose, but affected isomaltose hydrolysis less [13].
• 1H NMR spectroscopy assignments have been obtained for starch acetates using COSY and HOHAHA experiments by comparison with the spectra of amylose triacetate and of peracetylated malto-oligosaccharides (maltotriose, maltotetraose, maltoheptaose) [14].
• The purified recombinant enzyme exhibited optimum activity at 75 degrees C and pH 5 with citrate-phosphate buffer and retained 60% of residual activity after 72 h of incubation at 80 degrees C. The recombinant enzyme was active on maltooligosaccharides such as maltotriose, maltotetraose, maltopentaose and maltoheptaose [15].
• The main products for hydrolysis of maltoheptaose by the enzyme were maltotriose and maltotetraose [16].

Gene context of Maltoheptaose

• The hydrolysis of DP 4900-amylose, reduced (r) DP18-maltodextrin and maltoheptaose (catalysed by AMY1 and AMY2) was followed in the absence and in the presence of inhibitor [17].
• (a) Collisional activation of permethylated oligosaccharide molecular ions (MS2) as illustrated by maltoheptaose, produces abundant fragments from glycosidic bond cleavages which indicate composition and sequence, and weak cross-ring cleavage products which denote specific linkages within the oligosaccharide [18].
• Glycogen-enzyme interactions were modeled starting from the crystallographic AS: maltoheptaose complex, where two key oligosaccharide binding sites, OB1 and OB2, were identified [19].
• At a 40% digestion point of maltoheptaose (G7), for example, maltooligosaccharide products larger than maltodecaose (G10) amounted to approx. 60% of the total product from the mutant enzyme reaction, whereas no such large products were observed in the native enzyme reaction [20].
• In pH 10.0 buffers, tetrakis(4-sulfonatophenyl)porphyrin (TSPP) has been found to form complexes with malto-oligosaccharides from maltose to maltoheptaose and soluble starch [21].

Analytical, diagnostic and therapeutic context of Maltoheptaose

• The inactive E328Q amylosucrase variant has been co-crystallized with maltoheptaose, and the structure was determined by x-ray crystallography to 2.2 A resolution, revealing a maltoheptaose binding site in the B'-domain somewhat distant from the active site [3].
• Titration studies with two ligands, maltoheptaose and beta-cyclodextrin, show the existence of two binding sites [22].
• We used high-performance liquid chromatography (HPLC) to establish the action pattern of maltoheptaose under the test conditions: (A) the action pattern of alpha-amylase, (B) that of the combined action of alpha-amylase and alpha-glucosidase [23].
• The detection limit can also be decreased by simple on-line cartridge filtration to 200 attomol which is 10(5) times better than that of free maltoheptaose [24].

References