1. Microsomal fractions of lactating rabbit mammary gland incubated with UDP-glucose formed lipid-linked mono- and oligo-saccharides. The lipid-linked monosaccharide had chromatographic properties similar to those of dolichol phosphate mannose and yielded glucose on acid hydrolysis. 2. Incubation of the microsomal fraction with GDP-[U14C]-mannose yielded an oligosaccharide lipid of approximatel...

Incubation of mouse myeloma microsomes with GDP-[(14)C]mannose results in the biosynthesis of [(14)C]mannose phosphoryl dolichol [Baynes, J. W., Hsu, A.-F. & Heath, E. C. (1973) J. Biol. Chem. 248, 5693-5704] and a [(14)C]mannose- and N-acetylglucosamine (GlcNAc)-containing oligosaccharide derivative of dolichol. Thus, [(14)C]mannose phosphoryl dolichol and [(14)C]mannose-labeled oligosaccharid...

d-Galacturonic acid 1-phosphate was found to be one of the products formed during hydrolysis of the cell wall lipopolysaccharide of Xanthomonas campestris in 0.01 n acetic acid at pH 3.3. The molecule was shown to consist of equimolar amounts of d-galacturonic acid and phosphate. Resistance to borohydride reduction before, but not after, treatment with Escherichia coli alkaline phosphatase indi...

beta-Hexosaminidase B purified from human fibroblast secretions was used as a ligand to study phosphomannosyl-enzyme receptors in membranes from rat tissues. Enzyme binding to rat liver membranes was saturable, competitively inhibited by mannose 6-phosphate, not dependent on calcium, and destroyed by prior treatment of the hexosaminidase with either alkaline phosphatase or endoglycosidase H. Mo...

The antibiotic tunicamycin was separated into 16 different components using reversed-phase high performance liquid chromatography. The effect of the eight major tunicamycin homologues on protein glycosylation and protein biosynthesis was examined. All homologues tested inhibited lipid-mediated protein glycosylation in chick or mouse fibroblasts. These homologues also inhibited the transfer of N...

BALB/3T3 fibroblasts (3T3) were observed to secrete latent, pepsin-activatable forms of cathepsin B and cathepsin L as well as an active form of beta-glucuronidase when cultured in the absence of serum. The secretion of these proteins was stimulated by the cation ionophore monensin: cathepsin B, 4.3-fold; cathepsin L, 7.2-fold; and beta-glucuronidase, 3.1-fold. These increases were accompanied ...