Published in FEBS Letters
The recent crystal structures of the voltage-gated potassium channel KvAP and its isolated voltage-sensing ‘paddle’ (composed of segments S1–S4) challenge existing models of voltage gating and raise a number of questions about the structure of the physiologically relevant state. We investigate a possible gating mechanism based on the crystal struct...
Published in BBA - Biomembranes
The major outer membrane protein of Haemophilus influenzae type b (Hib) is porin ( M r 37,782; 341 amino acids). Porins were purified from Hib strains representative of the three outer membrane protein subtypes 1H, 2L and 6U, reconstituted into artificial planar bilayers, and tested for their voltage dependency. At membrane potentials of 50–80 mV, ...
Published in BBA - Biomembranes
A porin preparation from Escherichia coli 0111:B4 consisting of Omp F and Omp C (with Omp F in excess) was purified by salt extraction procedures and investigated in bilayer lipid membranes formed according to the Montal-Mueller technique. The porin preparation was added to the KCl electrolyte compartment of the Montal-Mueller cell which was connec...
Published in BBA - Biomembranes
Calcium-depleted human neutrophils are depolarised when suspended in calcium-free media containing sodium ions, and are repolarised by extracellular replenishment of Ca 2+. The depolarisation is due to a high inward sodium current, which is blocked by calcium and by several other divalent cations, but not by barium. Addition of calcium results in a...
Published in BBA - Biomembranes
Incorporation of Megatura crenulata hemocyanin into planar phospholipid bilayers results in the formation of ionic channels whose conductance can be directly measured. We have studied the effects of the pH on the electrical properties of these channels in the presence both of a K 2SO 4 solution, at high and low concentration, and of a KCl one. We h...
Published in BBA - Biomembranes
Incorporation of Megatura crenulata hemocyanin into phosphatidylcholine black lipid membranes results in the formation of ion channels. Channel properties depend on many factors, three of which are examined in this work: type and concentration of electrolyte and applied voltage. Eight cations at different concentrations have been used. Instantaneou...
