Growth of Aerobacter aerogenes PRL-R3 on the unnatural hexose l-mannose as a sole carbon source is dependent upon the selection of a mutant. Growth of the mutant on l-mannose did not require the synthesis of novel enzymes for the degradation of l-mannose, since enzymes of the l-rhamnose degradative pathway could serve this function. However, unlike most other apparent gain mutations that have b...

A novel alpha-mannosidase has been identified in rat liver endoplasmic reticulum (ER) which at neutral pH processes the Man9GlcNAc oligosaccharide of glycoproteins by specifically cleaving the terminal mannose residue of the alpha 1,6-linked chain to yield Man8GlcNAc, isomer C. This enzyme accounted for about half of the total ER alpha-mannosidase activity and was fully active at the concentrat...

Recent work demonstrated that a mannose receptor is involved in the phagocytosis of rod outer segments by the rat retinal pigment epithelium (RPE). In this study the binding of soluble mannose-containing ligands by human RPE explants is described. In addition, the authors report the isolation of a mannose receptor from human RPE and describe its relationship to the macrophage mannose receptor. ...

Acanthamoeba keratitis is a sight-threatening corneal infection. In a recent study, the saccharide mannose has been shown to inhibit the binding of Acanthamoeba organisms to the epithelium of the cornea (L. D. Morton, G. L. McLaughlin, and H. E. Whiteley, Infect. Immun. 59:3819-3822, 1991). In an attempt to determine the molecular mechanism by which acanthamoebae adhere to the surface of the co...

The lipopolysaccharide structure of the nitrogen-fixing bacterium Rhizobium leguminosarum differs from that of Escherichia coli in several ways, one of which is the sugar composition of the core. The E. coli inner core consists of 3-deoxy-D-manno-octulosonic acid (Kdo) and L-glycero-D-manno-heptose (heptose), while the inner core of R. leguminosarum contains 2-keto-3-deoxy-D-manno-octulosonic a...