A protein-glucan intermediate during paramylon synthesis

Publisher Website
Google Scholar
Abstract
A sodium deoxycholate extract containing glucosyltransferase activity was obtained from a particulate preparation from Euglena gracilis. It transferred glucose from UDP-[14C]glucose into material that was precipitated by trichloroacetic acid. This material released .beta.-(1 .fwdarw. 3)-glucan oligosaccharides into solution on incubation with weak acid, weak alkali and .beta.-(1 .fwdarw. 3)-glucosidase. The products of the incubation of the deoxycholate extract with UDP-[14C]glucose were analyzed by sodium dodecyl sulfate/polyacrylamide-gel electrophoresis. Radioactive bands were obtained that had the properties of .beta.-(1 .fwdarw. 3)-glucan covalently linked to protein by a bond labile to weak acid. High MW material containing a .beta.-(1 .fwdarw. 3)-glucan was also shown to be present by gel filtration. The bond linking glucan to aglycone is possibly a pyrophosphate linkage. Possibly in E. gracilis .beta.-(1 .fwdarw. 3)-glucan (paramylon) is synthesized on a protein primer.