Effect of benzyl alcohol and ethanol on cold-shock response ofBacillus subtilis

Benzyl alcohol and ethanol were found to exhibit an opposite effect on cold adaptation ofBacillus subtilis. The growth lag induced in bacteria by temperature shift-down was reduced in the presence of benzyl alcohol from 80 to 58 min, whereas ethanol prolonged this interval up to 102 min. In parallel, the physical state of the cytoplasmic membrane in intact bacteria was examined with the help of steady-state fluorescence anisotropy of diphenylhexatriene. Benzyl alcohol decreased the anisotropy as a consequence of membrane fluidization whereas ethanol increased its value, suggesting membrane rigidization. The correlation of growth and fluorescence data indicates that the control of membrane structure represents an important part of bacterial adaptation to cold. Dedicated to Professor C. John on the occasion of the his 75th birthday     

Rapid electrotransfer of proteins from polyacrylamide gel to nitrocellulose membrane using surface-conductive glass as anode

A new type of inexpensive horizontal apparatus for the electrophoretic transfer of proteins from a gel to an immobilization membrane has been developed. In this system, gel and membrane were directly pressed between two flat electrodes. A surface-conductive glass was used as anode and a stainless-steel plate as cathode. Proteins could be transferred from polyacrylamide gel to nitrocellulose sheet, with a yield of at least 90% in 60-90 min, without overheating, using a voltage gradient of 30-40 V/cm. Moderate volumes of separate anodic (with 20% methanol) and cathodic (with 0.1% sodium dodecyl sulfate) buffers were suited for optimal transfer of proteins with relative molecular mass (Mr) in the 14,000-94,000 range.     

A stage in glycolysis controls the metabolic adjustments of vertebrate rod photoreceptors upon illumination

The factors affecting the metabolic adjustments of toad rod photoreceptors were studied by monitoring the oxygen utilization of excised retinas and by measuring rod outer segment ATP and GTP concentrations. Respiratory adjustments upon illumination were observed when glucose or fructose was provided in the perfusate, but not when a glycolytic inhibitor was added to the perfusate containing glucose and pyruvate, or when a substrate beyond glycolysis or from a later stage of glycolysis was substituted for glucose. The amplitudes of the respiratory adjustments to illumination were dependent on the concentration of glucose in the perfusate. The ATP and GTP concentration changes were dependent on respiratory adjustments, including glycolytic effects, and on the levels of illumination. The data suggest a control point within glycolysis for light-induced adjustments of respiration, possibly at phosphofructokinase.