Purification and phosphorylation of initiation factor eIF-2 from rabbit skeletal muscle

Core particle DNA unfolding and refolding are followed by stopped-flow circular dichroism technique. When core particles are dissociated in the stopped-flow cuvette, the high CD deviation corresponding to the dissociated state is reached in the first millisecond, which means that the dissociation process is completed within the dead time of the apparatus which is ～1 ms. The same conclusion can be drawn when core particles are reassociated, since the low CD value, typical of the associated state, is immediately reached. Similarly histone release from chromatin is a very fast process. We also include some points of discussion about core particle assembly process.     

Peptide-receptor protein relationships: importance in estradiol feedback

Aspartate, glutamate, serine and glycine all permeate the inner membrane of mitochondria isolated from both etiolated and green plant tissues. No significant difference was found in the transport characteristics shown by mitochondria from either tissue. Influx of each amino acid appears diffusional because substrate saturation was not observed and there was no indication of specific inhibition or a requirement for a compensatory or counter ion for uptake. In contrast, uptake of the keto acid pyruvate did appear saturable. Inhibition by α-cyano-4-hydroxycinnamate, mersalyl and FCCP, but not valinomycin, suggests a carrier and a ΔpH mediate pyruvate transport into the matrix.     

The induction of sensitivity to gibberellin in aleurone tissue of developing wheat grains

Aleurone tissue from undried immature developing wheat grains (Triticum aestivum L. cv. Sappo), normally insensitive to gibberellic acid, can be made to respond to the hormone by a series of temperature treatments. Incubation of the de-embryoed grains at temperatures above 27° C for at least 8 h causes the tissue to become sensitive. Prolonged incubation at temperatures below 27° C does not effect a change in sensitivity. In addition to the requirement for exposure to an elevated temperature for a period of several hours the tissue must also subsequently be subjected to a period at a lower temperature for just a few seconds for the response to be observed. Once sensitized, the tissue remains responsive to gibberellic acid for substantial periods of time. Exposure of the tissue to temperatures which induce sensitivity to gibberellic acid also results in an increased leakage of amino acids. It is suggested that the increase in sensitivity to gibberellin requires two separate processes to take place. One could be a homeoviscous adaptation of the cell membranes in response to elevated temperature, the other a subsequent, permanent change in conformation of membrane components.     

Steroid hormone effects on growth and apical dominance of sunflower

External application of estradiol-17β increased shoot growth but decreased root growth of sunflower seedlings. It completely inhibited cotyledonary axillary bud development in decapitated plants at the concentration of 1 μg/plant. Concentrations lower than this promoted cotyledonary axillary bud formation. Testosterone on the other hand inhibited both shoot and root growth and promoted cotyledonary axillary bud formation at all the concentrations used. Progesterone at high (0.25,μg/plant) concentration promoted shoot growth but inhibited root growth. A low concentration (0.1 μg/plant) of progesterone produced the opposite effect.     

Essential oil and terpenoids of Mikania micrantha

Twenty-seven mainly terpenoid constituents were identified in the essential oil of Mikania micrantha whole plant. Higher terpenoids present in the same plant included two kaurene derivatives and taraxasterol.     

The sterol composition of mushrooms

Sterols were isolated from ten mushrooms, Hygrocybe punicea, Lampteromyces japonicus, Leucopaxillus giganteus, Lentinus edodes, Flammulina velutipes, Amanita caesarea, Coprinus atramentarius, Russula foetens, R. nigricans and R. senecis. The compositions of the sterol fractions were determined by GLC, combined GC/MS, and ¹H NMR. Ergosterol was present in all the mushrooms. Other sterols found were 5α-cholest-7-en-3β-ol and ergosta-5,7-dien-3β-ol. Ergosta-5,8,22-trien-3β-ol was isolated from F. velutipes.     

Chirality of the acyl group of β-hydroxy-β-methylglutarylhydroxyabscisic acid

The β-carbon of the acyl group of β-hydroxy-β-methylglutarylhydroxyabscisic acid was shown to possess R-configuration by HPLC analysis of the reduced product.