Maltotetraose-producing amylases

Naltotetraose-producing Amylases. An exo-acting amylase that produces predominantly maltotetraose from starch was demonstrated in culture fluid from Pseudomonas stutzeri by Robyt and Ackerman... 

Anomeric form of the hvdrolvzed products. The action pattern of the purified amylase was found to be an exotype as shown above. Exo-amylases such as glucoamylase and beta-amylase are known to produce saccharides with beta configuration. However, results indicate that both maltohexaose produced from amylose and maltotetraose produced from maltohexaose are in alpha configuration as shown in Figure 11. Therefore, this enzyme must be considered to belong a unique group(ll-15) of alpha-... 

Pullulan is hydrolyzed by pullulanase at the a-(l - 6) bonds, producing maltotriose plus some maltotetraose. Salivary alpha amylase cleaves at the maltotetraosyl units, when the a-(1 -> 4) linkage next to the a-(1 -> 6) bond and towards the reducing end of the maltotetraose unit is split (dotted arrow marked A in 108). The size of units released by alpha amylase, as judged... 

The enzyme is readily prepared, in an apparently pure form, from the culture filtrates of this pseudomonad, and has a specific activity comparable to that of crystalline, sweet-potato befa-amylase. The exo action of the enzyme is analogous to that of heta-amylase, but maltotetraose residues, not maltose residues, are removed. The action of the enzyme is halted by branch points, so that limit dextrins are produced from glycogen and amylopectin. The specificity of the enzyme for linkages in the region of branch points has not yet been ascertained. Some applications of this enzyme will be discussed later (see p. 318). 

Takasaki, Y. 1983. An Amylase Producing Maltotetraose and Maltopentaose from Bacillus Circulans. Agricultural and Biological Chemistry 47 2193-2199. 

There is an exo-acting bacterial a-amylase, elaborated by Pseudomonas stutzeri, that exclusively produces maltotetraose from starch [10]. The enzyme hydrolyzes maltotetraose units from the nonreducing ends of the starch chains, and, like P-amylase, it will not bypass the a-1 6 branch linkages of amy-... 

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