23 research outputs found
Changes in polygalacturonase, pectin lyase and cellulase in tomato plants, associated withFusarium inoculation
Interference between velvetleaf (Abutilon theophrasti Medic.) and soybean (Glycine max (L.) Merr.) I. Growth
DATURA STRAMONIUM ALLELOCHEMICALS: LONGEVITY IN SOIL, AND ULTRASTRUCTURAL EFFECTS ON ROOT TIP CELLS OF HELIANTHUS ANNUUS L.
A tree-ring study of Norway spruce infected with the wood-destroying fungus Armillaria mellea
Modification of flower sex and acid phosphatase activity by phthalimides in female plants of Morus nigra L.
Biochemical changes in pigeonpea (Cajanus cajan (L.) Millsp.) leaves in relation to resistance against sterility mosaic disease
Effect of short-chain primary alcohols on fluidity and activity of sarcoplasmic reticulum membranes
Intramolecular excimer formation with the fluorescent probe 1,3-di( 1 -pyrenyl)propane, differential
scanning calorimetry, and X-ray diffraction were used to assess the effect of ethanol, 1-butanol, and 1-hexanol
on the bilayer organization in model membranes, sarcoplasmic reticulum (SR) lipids and native SR
membranes. These alcohols have fluidizing effects on membranes and lower the main transition temperature
of dimyristoylphosphatidylcholine (DMPC), but only 1-hexanol alters the cooperativity of the phase transition
and significantly increases the thickness of DMPC bilayers. The interaction of the three alcohols with the
SR Ca2+ pump was also investigated. Hydrolysis of ATP and coupled Ca2+ uptake are differently sensitive
to the three alcohols. Whereas ethanol and I-butanol inhibited the Ca2+ uptake, I-hexanol stimulated it.
Nevertheless, the energetic efficiency of the pump (Ca2+/ATP) is not significantly affected by ethanol or
1-hexanol, but uncoupling was observed with 1-butanol at high concentrations. The different effects of alcohols
on the activity of SR membranes rule out an unitary mechanism of action on the basis of fluidity changes
induced in the lipid bilayer. Depending on the chain length, the alcohols interact with the SR membranes
in different domains, perturbing differently the Ca2+-pump activity