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Regular intake of fucosylated oligosaccharides has been associated with several benefits for human health, particularly for new-borns. Since these biologically active molecules can be found naturally in human milk, research efforts have been focused on the alternative synthetic routes leading to their production. In particular, utilization of fucosidases to perform stereoselective transglycosylation reactions has been widely investigated. Other reasons that bring these enzymes to the spotlight are their role in viral infections and cancer proliferation. Since their involvement in the pathogenesis of these diseases have been widely described, fucosidases have become a target in newly developed therapies. Finally, activity disorders of biologically important fucosidases can lead to health problems such as fucosidosis. What is common for both mechanisms is the interaction between the enzyme and substrates in and around the active site. Therefore, this review will analyse different substrate structures that have been tested in terms of their interaction with fucosidases active sites, either in synthesis or inhibition reactions. The published results will be compared from this perspective. [ABSTRACT FROM AUTHOR]

In recent years, the synthesis of human milk oligosaccharides, particularly fucooligosaccharides, has been investigated. These oligosaccharides provide protection against gastrointestinal diseases for newborns, among other functionalities. α-L-fucosidase from Thermotoga maritima of GH29 family has been reported to produce fucooligosaccharides by means of a transfucosylation reaction. However, the interaction between acceptor and donor substrates, and the enzyme has been little studied. For that reason, and due to the importance of fucooligosaccharides, the present study proposes a theoretical synthesis route employing α-L-fucosidase from T. maritima, lactose as acceptor substrate and pNP-fucose as fucosyl donor. A molecular docking study was carried out using crystallographic structure of α-L-fucosidase from Protein Data Bank. By simulating the theoretical synthesis with T. maritima fucosidase, it was observed that lactose interacts with the enzyme in regions other than the active site. However, it is approaching the active site when the fucose is in the position to form the enzyme-substrate complex. This finding may explain the transfucosylation yield documented in the literature when the proportion of fucosyl acceptor substrate increases concerning that of the donor substrate. [ABSTRACT FROM AUTHOR]

The effects of water activity (aw), pH, and temperature on transglycosylation activity of α-L-fucosidase from Thermotoga maritima in the synthesis of fucosylated oligosaccharides were evaluated using different water-organic cosolvent reaction systems. The optimum conditions of transglycosylation reaction were the pH range between 7 and 10 and temperature 90–95 °C. The addition of organic cosolvent decreased α-L-fucosidase transglycosylation activity in the following order: acetone > dimethyl sulfoxide (DMSO) > acetonitrile (0.51 > 0.42 > 0.18 mM/h). However, the presence of DMSO and acetone enhanced enzyme-catalyzed transglycosylation over hydrolysis as demonstrated by the obtained transglycosylation/hydrolysis rate (rT/H) values of 1.21 and 1.43, respectively. The lowest rT/H was calculated for acetonitrile (0.59), though all cosolvents tested improved the transglycosylation rate in comparison to a control assay (0.39). Overall, the study allowed the production of fucosylated oligosaccharides in water-organic cosolvent reaction media using α-L-fucosidase from T. maritima as biocatalyst. [ABSTRACT FROM AUTHOR]