Comparative Characterization of Hydrolysis and Transglycosylation Catalyzed by beta-1,3-Glucanases from Various Sources

V. V. Sova,^1,2 T. N. Zvyagintseva,¹ T. G. Svetasheva,¹ Yu. V. Burtseva,¹ and L. A. Elyakova¹

¹Pacific Institute of Bioorganic Chemistry, Far-Eastern Branch, Russian Academy of Sciences, pr. 100-letiya Vladivostoka 159, Vladivostok, 690022 Russia; fax: (4232) 31-4050; E-mail: elyakov@piboc.marine.su

²To whom correspondence should be addressed.

Submitted May 15, 1997.

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Hydrolytic and transglycosylating activities of endo-beta-1,3-glucanase and exo-beta-1,3-glucanase isolated from marine and terrestrial invertebrates, marine bacteria, and higher plants were comparatively studied. The effects of structural features of substrates on hydrolysis and transglycosylation catalyzed by these enzymes were investigated. Endo-beta-1,3-glucanases had equal hydrolytic activities but differed in transglycosylation abilities. Endo-beta-1,3-glucanases from marine mollusks and marine bacteria displayed the highest transglycosylating activities, whereas plant endo-beta-1,3-glucanases had the lowest transglycosylating activities. The enzymes studied in this work had different rates of hydrolysis of 1,3;1,6-beta-D-glucans with various contents of beta-1,6 linkages. Endo-beta-1,3-glucanase from chitons and exo-beta-1,3-glucanase LII from the terrestrial mollusk were the most structure-sensitive in hydrolysis reactions, whereas endo-beta-1,3-glucanases LIII and LIV from marine mollusks were the least sensitive. In contrast, the rates of transglycosylation reactions mediated by endo-beta-1,3-glucanases LO and LIV strongly depended on the substrate structure and sharply decreased with a decrease in their contents of beta-1,6-linked glucose residues. Laminaran from Laminaria cichorioides was found to have an optimal structure for all enzymes studied, both in hydrolysis and transglycosylation reactions.

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KEY WORDS: beta-1,3-glucanase, hydrolysis, transglycosylation.

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