The formation of cell envelope components of Bifidobacterium bifidum subsp. pennsylvanicus was studied by measuring the incorporation of [(3)H]glycine, (14)C-labeled fatty acids, and N-benzoyl-[(14)C]glucosamine into the membrane protein, membrane lipids, and cell wall peptidoglycan, respectively. Inhibition of peptidoglycan synthesis by antibiotics (penicillin G, vancomycin, d-cycloserine, and...

Since the 1880s, concept of compartmentalizing through membranes has taken a firm place in cell physiology and defined objects, methods, goals physiologists’ research for decades. A huge mass biologists know about important role intra-membrane pumps, channels, lipids, various hypotheses origin life often begin with explanations how lipid membrane occurred, without which it is impossible to imag...

Mutation studies previously showed that the lentivirus lytic peptide (LLP2) sequence of the cytoplasmic C-terminal tail of the HIV-1 gp41 envelope protein inhibited viral-initiated T-cell death and T-cell syncytium formation, at which time in the HIV life cycle the gp41 protein is embedded in the T-cell membrane. In striking contrast, the mutants did not affect virion infectivity, during which ...

Bilayers are synthetically made cell membranes that are used to study cell membrane properties and make functional devices that incorporate inherent properties of the cell membranes. Lipids and proteins are two of the main components of a cell membrane. Lipids provide the structure of the membrane in the form of two leaflets or layers that are held together by the amphiphilic interaction betwee...

Patches (lateral heterogeneities) of cell surface membrane proteins and lipids have been imaged by a number of different microscopy techniques. This patchiness has been taken as evidence for the organization of membranes into domains whose composition differs from the average for the entire membrane. However, the mechanism and specificity of patch formation are not understood. Here we show how ...

Lipids, in particular phospholipids, are essential components of membrane systems, and the measurement of phospholipids and cholesterol in plasma and tissues is helpful in diagnosis. Phospholipids represent about 60 to 70% of total red cell (RBC) lipids, while about 25% is free cholesterol. Lipids in RBC are present in a dynamic state of equilibrium, and the RBC have the capacity for rapid exch...

G protein-coupled receptors (GPCRs) are the largest class of molecules involved in signal transduction across cell membranes and are major drug targets. Since GPCRs are integral membrane proteins, their structure and function are modulated by membrane lipids. In particular, membrane cholesterol is an important lipid in the context of GPCR function. Solubilization of integral membrane proteins i...

Pore-forming toxins (PFT) are water-soluble proteins that possess the remarkable ability to self-assemble on the membrane of target cells, where they form pores causing cell damage. Here, we elucidate the mechanism of action of the haemolytic protein fragaceatoxin C (FraC), a α-barrel PFT, by determining the crystal structures of FraC at four different stages of the lytic mechanism, namely the ...

Our view of the lateral organization of lipids and proteins in the plasma membrane has evolved substantially in the last few decades. It is widely accepted that many, if not all, plasma membrane proteins and lipids are organized in specific domains. These domains vary widely in size, composition, and stability, and they represent platforms governing diverse cell functions. The presynaptic plasm...