Amygdalin, the gentiobioside derivative of mandelonitrile commonly referred to as Laetrile, is presently under intensive investigation as a potential cancer chemotherapeutic agent. Because of this interest, we investigated the activity of beta-glucosidases that cleave glucose from amygdalin and from prunasin (mandelonitrile monoglucoside) in tissues from germ-free rats and in normal and neoplas...

Background It is well known that in the yeast S. cerevisiae the sugars sucrose and maltose/maltotriose are metabolized by different pathways: sucrose is hydrolyzed by extracellular invertase (encoded by SUC genes), while maltose and maltotriose are actively transported into the cell and hydrolyzed by intracellular a-glucosidases (both proteins encoded by the MAL genes). Nevertheless, several re...

Product inhibition of β-glucosidases (BGs) by glucose is considered to be a limiting step in enzymatic technologies for plant-biomass saccharification. Remarkably, some β-glucosidases belonging to the GH1 family exhibit unusual properties, being tolerant to, or even stimulated by, high glucose concentrations. However, the structural basis for the glucose tolerance and stimulation of BGs is stil...

Intracellular alpha-and beta-glucosidases were induced in cell suspensions of Pseu-domonas maltophilia by maltose or cellobiose, and the synthesis of these enzymes was sensitive to apparent catabolite repression by alpha-ketoglutarate.

Using a pulse-chase approach combined with immunoprecipitation, we showed that newly synthesized influenza virus hemagglutinin (HA) and vesicular stomatitis virus G protein associate transiently during their folding with calnexin, a membrane-bound endoplasmic reticulum (ER) chaperone. Inhibitors of N-linked glycosylation (tunicamycin) and glucosidases I and II (castanospermine and 1-deoxynojiri...

Membrane associated alpha-glucosidase activity was investigated in a methanogenic bioreactor (MR) and a biosulfidogenic bioreactor (SR). Temperature and pH optima studies showed temperature optima of 50 degrees C and pH optima of 8.0 for the alpha-glucosidases from both the MR and SR. Sulfide (at a concentration of 150 mg l(-1)) resulted in the complete loss of all alpha-glucosidase activity in...

In addition to the previously identified 4-alpha-glucanotransferase gene mgtA and the alpha-amylase gene amyA of Thermotoga maritima strain MSB8 we have now isolated three further genes encoding amylolytic enzymes from a gene library of this ancestral bacterium. The genes code for the extremely thermostable enzymes pullulanase (pulA), maltodextrin phosphorylase (agpA) and alpha-glucosidase (agl...

Thermoanaerobic bacteria are of considerable interest as producers of thermostable amylolytic enzymes. The soluble amylolytic enzyme system of Thermoanaerobacterium thermosaccharolyticum DSM 571 was fractionated into a pullulanase, a glucoamylase, and an alpha-glucosidase. The enzymes were purified to homogeneity and their physical and catalytic properties were studied. The pullulanase, which c...