Synthesis of the antibiotic cortalcerone from d-glucose using pyranose 2-oxidase and a novel fungal enzyme, aldos-2-ulose dehydratase
摘要:
Using two enzymes purified from the white-Tot fungus, PoLyporus obtusus, 5% solutions Of D-glucose have been quantitatively converted in vitro into D-arabino-hexos-2-ulose (D-glucosone) and subsequently into a compound having antimicrobial activity. The antibiotic has been shown by nuclear magnetic resonance and mass spectroscopy to be chemically identical to a previously described fungal metabolite known as cortalcerone. Based on kinetic analysis of the synthetic process, a pathway for the biosynthesis of cortalcerone is proposed, involving both chemical rearrangement and enzymically catalyzed steps. Two enzymes, pyranose 2-oxidase and a previously uncharacterized D-arabino-hexos-2-ulose-utilizing enzyme, may be sufficient for the biosynthesis of cortalcerone from glucose in vivo. The D-arabino-hexos-2-ulose-utilizing enzyme dehydrates certain aldosuloses and has been named aldos-2-ulose dehydratase. The enzyme, which appears to be a dimer of 95-kDa subunits, has been purified 450-fold. Additional properties of aldos-2-ulose dehydratase are described, including its apparent ability to catalyze two different steps in the proposed biosynthetic pathway for cortalcerone.
Synthesis of the antibiotic cortalcerone from d-glucose using pyranose 2-oxidase and a novel fungal enzyme, aldos-2-ulose dehydratase
摘要:
Using two enzymes purified from the white-Tot fungus, PoLyporus obtusus, 5% solutions Of D-glucose have been quantitatively converted in vitro into D-arabino-hexos-2-ulose (D-glucosone) and subsequently into a compound having antimicrobial activity. The antibiotic has been shown by nuclear magnetic resonance and mass spectroscopy to be chemically identical to a previously described fungal metabolite known as cortalcerone. Based on kinetic analysis of the synthetic process, a pathway for the biosynthesis of cortalcerone is proposed, involving both chemical rearrangement and enzymically catalyzed steps. Two enzymes, pyranose 2-oxidase and a previously uncharacterized D-arabino-hexos-2-ulose-utilizing enzyme, may be sufficient for the biosynthesis of cortalcerone from glucose in vivo. The D-arabino-hexos-2-ulose-utilizing enzyme dehydrates certain aldosuloses and has been named aldos-2-ulose dehydratase. The enzyme, which appears to be a dimer of 95-kDa subunits, has been purified 450-fold. Additional properties of aldos-2-ulose dehydratase are described, including its apparent ability to catalyze two different steps in the proposed biosynthetic pathway for cortalcerone.
The invention provides a synthetic
C. difficile
PS-II cell wall saccharide. The invention also provides a process for purifying
C. difficile
PS-II saccharide from
C. difficile
bacterial cells resulting in reduced contamination. The saccharides may be used in vaccines, particularly as conjugates with carrier proteins.
purified and crude material obtained directly from the enzymaticoxidation, subjected to filtration and lyophilization only. High selectivities towards D-fructose were observed for both starting materials over a Ru/C catalyst. Hydrogenation of the crude D-glucosone was, however, inhibited by the impurities resulting from the enzymaticoxidation process. Catalyst deactivation was observed in the case
The invention provides a synthetic C. difficile PS-II cell wall saccharide. The invention also provides a process for purifying C. difficile PS-II saccharide from C. difficile bacterial cells resulting in reduced contamination. The saccharides may be used in vaccines, particularly as conjugates with carrier proteins.
Synthesis of the antibiotic cortalcerone from d-glucose using pyranose 2-oxidase and a novel fungal enzyme, aldos-2-ulose dehydratase
Using two enzymes purified from the white-Tot fungus, PoLyporus obtusus, 5% solutions Of D-glucose have been quantitatively converted in vitro into D-arabino-hexos-2-ulose (D-glucosone) and subsequently into a compound having antimicrobial activity. The antibiotic has been shown by nuclear magnetic resonance and mass spectroscopy to be chemically identical to a previously described fungal metabolite known as cortalcerone. Based on kinetic analysis of the synthetic process, a pathway for the biosynthesis of cortalcerone is proposed, involving both chemical rearrangement and enzymically catalyzed steps. Two enzymes, pyranose 2-oxidase and a previously uncharacterized D-arabino-hexos-2-ulose-utilizing enzyme, may be sufficient for the biosynthesis of cortalcerone from glucose in vivo. The D-arabino-hexos-2-ulose-utilizing enzyme dehydrates certain aldosuloses and has been named aldos-2-ulose dehydratase. The enzyme, which appears to be a dimer of 95-kDa subunits, has been purified 450-fold. Additional properties of aldos-2-ulose dehydratase are described, including its apparent ability to catalyze two different steps in the proposed biosynthetic pathway for cortalcerone.