Cell-free protein synthesis for analysis by NMR spectroscopy.

Cell-free protein synthesis offers fast and inexpensive access to selectively isotope labeled proteins that can be measured by NMR spectroscopy in the presence of all the unlabeled proteins in the reaction mixture. No chromatographic purification is required. Using an extract from Escherichia coli in a simple dialysis system, the target protein can be prepared at a typical concentration of about 1 mg/ml, which is sufficient for subsequent analysis by NMR.

Surface movement in water of splendipherin, the aquatic male sex pheromone of the tree frog Litoria splendida.

The aquatic sex pheromone splendipherin (GLVSSIGKALGGLLADVVKSKGQPA-OH) of the male green tree frog Litoria splendida moves across the surface of water to reach the female. Surface pressure and X-ray reflectometry measurements confirm that splendipherin is a surface-active molecule, and are consistent with it having an ordered structure, whereby the hydrophilic portion of the peptide interacts with the underlying water and the hydrophobic region is adjacent to the vapour phase. The movement of splendipherin over the surface of water is caused by a surface pressure gradient.

Cupiennin 1a, an antimicrobial peptide from the venom of the neotropical wandering spider Cupiennius salei, also inhibits the formation of nitric oxide by neuronal nitric oxide synthase.

Cupiennin 1a (GFGALFKFLAKKVAKTVAKQAAKQGAKYVVNKQME-NH2) is a potent venom component of the spider Cupiennius salei. Cupiennin 1a shows multifaceted activity. In addition to known antimicrobial and cytolytic properties, cupiennin 1a inhibits the formation of nitric oxide by neuronal nitric oxide synthase at an IC50 concentration of 1.

Host-defence peptides of Australian anurans: structure, mechanism of action and evolutionary significance.

Host-defence peptides secreted from the skin glands of Australian frogs and toads, are, with a few notable exceptions, different from those produced by anurans elsewhere. This review summarizes the current knowledge of the following classes of peptide isolated and characterized from Australian anurans: neuropeptides (including smooth muscle active peptides, and peptides that inhibit the production of nitric oxide from neuronal nitric oxide synthase), antimicrobial and anticancer active peptides, antifungal peptides and antimalarial peptides. Other topics covered include sex pheromones of anurans, and the application of peptide profiling to (i).