The role of phospholipids in the activity of UDP-D-galactose: D-xylose galactosyltransferase (galactosyltransferase I) from embryonic chick cartilage was investigated. Phospholipase C treatment of particulate galactosyltransferase I caused inactivation of this enzyme to the extent of 60 to 70% as well as hydrolysis of 75 to 80% of the membrane phospholipids. Addition of phospholipid restored ac...

The role of phospholipids in the activity of UDP-D-galactose:D-xylose galactosyltransferase (galactosyltransferase I) from embryonic chick cartilage was investigated. Phospholipase C treatment of particulate galactosyltransferase I caused inactivation of this enzyme to the extent of 60 to 70% as well as hydrolysis of 75 to 80% of the membrane phospholipids. Addition of phospholipid restored act...

BACKGROUND Candida species, in conditions of microbiota imbalance or decreased immune defenses, may be one of the main human fungal pathogens. Virulence factors constitute the mechanisms used by the fungus to avoid host defenses. AIMS This study aimed to investigate the in vitro production of virulence factors, such as hemolytic activity, and deoxyribonuclease (DNase), proteinase, and phospho...

The polymeric Ig receptor (pIgR) transcytoses its ligand, dimeric IgA (dIgA), from the basolateral to the apical surface of epithelial cells. Although the pIgR is constitutively transcytosed in the absence of ligand, binding of dIgA stimulates transcytosis of the pIgR. We recently reported that dIgA binding to the pIgR induces translocation of protein kinase C, production of inositol triphospha...

We have examined the effects of phospholipase C pretreatment on Ca2+ transport in highly purified canine cardiac sarcolemmal vesicles. Na+-Ca2+ exchange, measured as Nai+-dependent Ca2+ uptake, is stimulated when 10-70% of the membrane phospholipid has been hydrolyzed. Although the phospholipase C treatment also increases sarcolemmal passive Ca2+ flux, the membrane maintains a sufficient permea...

The response of several Escherichia coli membranous enzymes to hydrolysis of up to 95 % of membrane phospholipid has been investigated. Purified phospholipase C of Bacillus cereus was utilized in these studies. The rate and extent of digestion of E. coli phospholipids was independent of whether the lipid was associated with membrane protein or extracted from membranes and sonically dispersed. P...

Recently we isolated a protein growth factor of 34 kDa from trophoblastic membranes of human placenta. A fraction (approximately equal to 50%) of the membrane-associated 34-kDa protein is peripherally associated--i.e., it can be released by high salt treatment. The remainder shows the characteristics of an integral membrane protein--i.e., its release requires detergent treatment. Here we report...