Maltase, from yeast

A convenient source of trehalase is bakers yeast. It is an a-n-glu-cosidase distinguishable from maltase by the damage suffered by the maltase on yeast storage. a,a-Trehalose added to bakers yeast is fermented (in aqueous suspension), but the a,a-trehalose stored within the yeast remains unaffected. Evidently, there is a spatial separation between yeast trehalase and its stored trehalose. The enzyme may be at the cell... 

Another derivative of conduritol B, 6-bromo-3,4,5-trihydroxycyclohex-1-ene (bromoconduritol), was found to be effective for covalent inhibition of glucosidases. It reacts rapidly with an a-glucosidase from yeast (maltase) at equimolar concentrations of enzyme and inhibitor. It also reacts with )3-glucosidases from Cicer arietum and Alocasia maxrorrhiza. ... 

Disaccharides resulting from a-glucosyl transfer from sucrose have been identified after the action of enzymes of several common microorganisms. Yasumura found two disaccharides in the partial hydrolyzates of sucrose produced by an enzyme from brewer s yeast. One was identified as turanose [0-a-D-glucopyranosyl-(i - 3)-D-fructofuranose] and the other as maltulose [0-a-D-glucopyranosyl-(i ->-4)-D-fructose]. Ishizawa, using isomaltose as the donor and a maltase from Takadiastase, obtained a new disaccharide which was tentatively identified as 0-a-D-glucopyranosyl-(i - i)-D-fructose on the basis of its optical rotation. 

Minute crystals from dil alcohol which retain 0.25 to 0.50 mol water after drying in vacuo. Indifferent taste. Dec 225. Shows mutarotation. [ejg1 +14.2 — +34.6 (15 hrs, c — 8). One gram dissolves in 8 ml water, in 1.5 ml boiling water almost insol in abs ale and ether. Reduces Fehling s soln. Hydrolysis with acid or emulsin yields 2 mols (-[)-glucose. Not fermented by brewers yeast, maltase, or in-vertase. 

Hill (1898) showed the reversal of hydrolysis with a maltase extracted from a brewer s yeast. He dried the organism to a powder, which he then heated to 100 °C while dry. The maltase was finally extracted from the yeast with 10 volumes of 0.1% (w/v) sodium hydroxide. The extract, which was neutral to litmus, not only hydrolysed maltose [a-o-Glc-(l - 4)-Glc (9)] to glucose, but also would synthesize a product from glucose which Hill believed, on the basis of a careful analytical study of the osazone, to be maltose. At a total sugar concentration of 40% (w/v) the reaction would approach its equilibrium position from either side (Table 1.4, Figure 1.2), and the synthesis was less effective at lower concentrations. Emmerling... 

To produce ethanol from starchy materials, such as cereal grains, the starch must first be converted into fermentable sugars, which are formed by starch degradation by amylases and maltases (see Section 4.5.6.1.3). For the production of beer, for example, yeast strains are selected that metabolise maltose and maltotriose (which... 

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