Biochemical synthesis of the medicinal sugar l-gulose using fungal alditol oxidase.

Some rare sugars can be potently medicinal, such as l-gulose. In this study, we present a novel alditol oxidase (fAldOx) from the soil fungus Penicillium sp. KU-1, and its application for the effective production of l-gulose. To the best of our knowledge, this is the first report of a successful direct conversion of d-sorbitol to l-gulose. We further purified it to homogeneity with a ∼108-fold purification and an overall yield of 3.26%, and also determined the effectors of fAldOx. The enzyme possessed broad substrate specificity for alditols such as erythritol (k _cat /K _M , 355 m ^-1  s ^-1 ), thus implying that the effective production of multiple rare sugars for medicinal applications may be possible.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have influenced the work reported in this paper.
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