Isomalto-dextranase, dextran hydrolysi

Mutation Studies of Isomalto-dextranase for Dextran Hydrolysis. 362... 

Fig. 16 a Chemical structures of dextran immobilized on a QCM plate through an avidin-biotin linkage, and b hydrolysis schemes of the dextran on the QCM plate catalyzed by isomalto-dextranase (wUd type, D198N, D266N, and D313N) and kinetic parameters obtained in this work... 

Table 5 Kinetic parameters of the wild type and mutants of isomalto-dextranase for the hydrolysis of the dextran immobilized on the 27-MHz QCM , and relative enzyme activ- ...

Both and H n.m.r. measurements on a bacterial dextran and its acetylated derivative and on a synthetic tri-O-benzyldextran have revealed the main features of their linear a-(l - 6)-linked structures. Bacterial dextrans from Streptococcus viridans B-1351, Streptobacterium dextranicum B-1254, and four strains of Leuconostoc mesenteroides have been subjected to methylation analysis.They differed with respect to the ease of methylation and subsequent hydrolysis of the methylated polysaccharides, owing to significant differences in the frequency and type of chain-branching. An enzymic approach has been used to obtain information on the frequency and distribution of chain-branching in dextrans. Thus, B-512 native dextran was treated with an endo-dextranase (from Pseudomonas UQM 733) and the products were examined by quantitative t.l.c. The relative amount of each oligosaccharide (i.e. linear isomalto-oligosaccharides of DP 2-5... 

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