The biosynthesis of galactofuranosyl residues in galactocarolose.
1. Cell-free extracts of Penicillium charlesii G. Smith were used in a study of the biosynthesis of the galactofuranose polymer, galactocarolose. 2. UDP-glucose and UDP-galactopyranose were precursors of galactocarolose and it was shown that the galactofuranose residues in the polymer were formed from glucose without fission of the hexose carbon chain. 3. A new nucleotide, UDP-alpha-d-galactofuranose, was formed by the system and was a major product when polymer synthesis was inhibited by F(-) or Zn(2+); the nucleotide was isolated and its structure determined. 4. UDP-alpha-d-galactofuranose was efficiently utilized for polymer synthesis and shown to be formed from the pyranose nucleotides. 5. A route for the biosynthesis of galactocarolose, involving a novel ring contraction of the hexose residue while still attached to the nucleotide, is proposed.
D002247:Carbon Isotopes; D002474:Cell-Free System; D002854:Chromatography, Paper; D005459:Fluorides / Q000494:pharmacology; D005685:Galactans; D005690:Galactose / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism; D008956:Models, Chemical; D010407:Penicillium / Q000254:growth & development / Q000378:metabolism; D011134:Polysaccharides / Q000096:biosynthesis*; D013053:Spectrophotometry; D014500:Uracil Nucleotides / Q000378:metabolism; D015032:Zinc / Q000494:pharmacology
D002247:Carbon Isotopes; D005685:Galactans; D011134:Polysaccharides; D014500:Uracil Nucleotides; C001269:galactocarolose; D005947:Glucose; D015032:Zinc; D005459:Fluorides; D005690:Galactose