
%0 Journal Article
%A Mascara, T 
%A Fincher, GB 
%T Biosynthesis of Arabinogalactan-Protein in <I>Lolium multiflorum</I> (Ryegrass) Endosperm Cells. II. <I>In vitro</I> Incorporation of Galactosyl Residues From UDPgalactose Into Polymeric Products
%J Functional Plant Biology
%D 1982/02/01
%V 9
%N 1
%P 31-45
%K 
%R https://doi.org/10.1071/PP9820031
%U https://www.publish.csiro.au/paper/PP9820031 
%X When mixed-membrane fractions from suspension-cultured Lolium multiflorum endosperm cells are incubated in vitro with UDP-[14C]galactose, 66% ethanol-insoluble products of apparent molecular weight greater than 60 000 are labelled in both galactosyl and glucosyl residues, suggesting that an active UDPgalactose 4-epimerase is present on the membrane fraction. The epimerase can be inhibited with ADPribose, to produce polymeric material in which [14C]galactosyl residues pre-dominate. While some of these residues appear to be associated with glycoproteins, affinity chromatography of the products on mouse myeloma protein J539-Sepharose provides evidence that &#946;-galactans containing 1,6-linkages are amongst the products.    Monosaccharide analyses and methylation data indicate that the mixed-membrane preparations contain associated polysaccharide of structure analogous to the 1,3;1,4-&#946;-glucans, arabinoxylans and arabino-3,6-galactans normally found in cell walls or secreted into the medium. 
