Chitin, the major structural polysaccharide of arthropods, is an important constituent of the insect extracellular structures, cuticle and gut peritrophic matrix. Synthesis of cuticular chitin is strictly coordinated with the ecdysone-regulated molting cycle of insect development (the term "ecdysone" is used in this paper instead of "ecdysteroids" since the exact ratio of various hormonal forms...

Since the discovery by Leloir and coworkers of uridine diphosphate glucose as the coenzyme in the “galacto-Walden&se” reaction (2), nucleotide-linked sugars have been shown to act as glycosyl donors in the synthesis of trehalose (3), sucrose (4), glucuronides (5), various disaccharides (6)) and hyaluronic acid (7). In the present communication, evidence will be presented that uridine diphosphat...

Staining with calcofluor white (CFW), which is known to bind chitin-rich areas of the cell wall, revealed a difference in the fluorescence intensity at the hyphal tip between Candida albicans hyphal cells that were grown in modified Lee (M-Lee) and SPG media. The fluorescence intensity at the tip increased with the addition of salts and sugar to SPG. The chitin levels per dry cell weight in cel...

The interaction between inhibitors of components of the fungal cell wall, glucan and chitin, was studied in vitro with the respective synthase enzyme inhibitors LY 303366 and nikkomycin Z. With Aspergillus fumigatus synergy was noted for inhibition and killing, and synergistic activity was also noted for some isolates of other species presently regarded as difficult to treat.

The non-reducing disaccharide trehalose is widely distributed among various organisms. It plays a crucial role as an instant source of energy, being the major blood sugar in insects. In addition, it helps countering abiotic stresses. Trehalose synthesis in insects and other invertebrates is thought to occur via the trehalose-6-phosphate synthase (TPS) and trehalose-6-phosphate phosphatase (TPP)...

To ascertain the directionality of chitin synthesis by yeast plasma membranes, the external surface of Saccharomyces cerevisiae protoplasts was labeled with ferritin--concanavalin A. After protoplast lysis, plasma membranes were isolated and treated with trypsin to activate chitin synthase (UDP-2-acetamido-2-deoxy-D-glucose:chitin 4-beta-acetamidodeoxy-D-glucosyl-transferase, EC 2.4.1.16). The ...

Development requires fertilization by a single sperm. In Caenorhabditis elegans, fertilization occurs in a sperm-filled spermatheca, implying the barrier to polyspermy is generated in this compartment. Eggshell chitin synthesis is initiated at fertilization, and chitin is deposited before the zygote exits the spermatheca. Whereas polyspermy is very rare in wild-type, here we report an incidence...

A bioinformatics search of the genome of the red flour beetle, Tribolium castaneum, resulted in the identification of two genes encoding proteins closely related to UDP-N-acetylglucosamine pyrophosphorylases (UAPs), which provide the activated precursor, UDP-N-acetylglucosamine, for the synthesis of chitin, glycoproteins and glycosylphosphoinositide (GPI) anchors of some membrane proteins as we...

De novo construction of a chitinous cell wall accompanies Blastocladiella emersonii zoospore germination. At least an order of magnitude increase in total hexosamine occurs during germination. This increase is into polymer (chitin) and occurs on schedule in the presence of cycloheximide. Uridine-5'-diphospho-N-acetylglucosamine (UDPGlcNAc), both the end product of hexosamine biosynthesis and a ...

In the course of search for potent inhibitors of chitin synthase II from natural resources, seven tannins and related compounds were isolated from the aerial part of Euphorbia pekinensis and identified as gallic acid (1), methyl gallate (2), 3-O-galloyl-(-)-shikimic acid (3), corilagin (4), geraniin (5), quercetin-3-O-(2"-O-galloyl)-beta-D-glucoside (6), and kaempferol-3-O-(2"-O-galloyl)-beta-D...