Biosynthesis of the sulfonolipid 2-amino-3-hydroxy-15-methylhexadecane-1-sulfonic acid in the gliding bacterium Cytophaga johnsonae

Abstract

The biosynthesis of the sulfonolipid 2-amino-3-hydroxy-15-methylhexadecane-1-sulfonic acid (capnine) was studied by measuring the incorporation of possible precursors into the lipid by cells grown in the presence of precursors which were labeled with stable isotopes. Cells grown on yeast extract in the presence of DL-[3,3-2H2]serine contained 40.1 mol% of the protein-bound serine and 5.0 mol% of the protein-bound cysteine derived from the labeled serine. Cells grown in the presence of DL-[3,3-2H2]cystine acid contained 86.4 mol% of the molecules that had two deuteriums. These results are consistent with the possibility that biosynthesis of capnine occurs by the condensation of 13-methylmyristoyl-coenzyme A with cysteic acid, in a reaction analogous to the condensation of a palmitoyl-coenzyme A with serine to form 3-keto-sphinganine during the biosynthesis of sphingolipids.