High-performance anion-exchange chromatography of ultraviolet-absorbing constituents of human urine

A 100-μl urine sample was chromatographed on a column packed with a strongly basic macroreticular anion-exchange resin (Diaion CDR-10, 5– μm diameter with a nominal 35% cross linkage). The elution was performed with a linear acetate gradient from 0 to 6.0 M at an average flow-rate of 0.72 ml/min and at an average pressure of 104 kg/cm². The relative standard deviation of retention times and peak height was ± 4% or less. The properties of the macroreticular anion-exchange resin, the effect of the particle size, the pH of acetate buffers, and the effect of the flow-rate of the eluent on the separation were investigated. Thirty three components of urine were then resolved and named.     

Analysis of Nuclear Accumulation of Influenza Nucleoprotein Antigen in the Presence of p-Fluorophenylalanine

When p-fluorophenylalanine (FPA) was added to influenza virus RI/5+-infected cells 4 hr after infection, virus-specific proteins were synthesized but infectious progeny virus was not produced. In these cells, synthesis of viral RNA was strongly inhibited and nucleoprotein (NP) antigen was found predominantly in the nucleus in contrast to untreated cells in which NP antigen was distributed throughout the whole cell. The intracellular location and migration of NP were examined by isotope labeling followed by fractionation of infected cells. In untreated cells, a large portion of the NP was present in the cytoplasm and most of it was detected in the form of ribonucleoprotein (RNP). In contrast, in FPA-treated cells little viral RNP was detectable and NP was present predominantly in the nucleus in a nonassembled, soluble form. When FPA was removed from the culture, synthesis of viral RNA was soon restored and a large amount of viral RNP appeared in the cytoplasm; this was followed by the production of infectious virus. The results of the experiments suggest that the NP synthesized in the presence of FPA is not assembled into viral RNP because of the lack of available RNA, and such NP migrates readily into the nucleus and accumulates there.     

Molecular cloning of rabbit CARP cDNA and its regulated expression in adriamycin-cardiomyopathy.

A full-length rabbit cDNA of cardiac adriamycin responsive protein (CARP) has been cloned. It shows high levels of identity at the amino acid sequence level (>86%) with the rat, mouse and human homologues. CARP mRNA levels are highly regulated in adriamycin-cardiomyopathy in rabbits.     

Meal feeding schedule and ventromedial hypothalamic lesions do not affect rhythm of pineal serotonin N-acetyltransferase activity in rats

Effects of meal feeding schedule and bilateral lesions of the ventromedial hypothalamus (VMH) on the circadian rhythm of pineal serotonin N-acetyltransferase (SNAT) activity were examined in rats, under LD (12:12) condition. Neither meal feeding nor VMH lesions affected the phase of the circadian rhythm of pineal SNAT activity, but the VMH lesions reduced the level. Meal feeding caused a shift of the phases of the daily rhythms of phosphoenolpyruvate carboxykinase and tyrosine aminotransferase activities in the liver. These findings suggest that the circadian rhythm of pineal SNAT activity is not entrained by the food intake, and that the VMH does not function as a master oscillator of the rhythm.     

Analysis of Slow Hyperpolarizing Potentials in Frog Taste Cells Induced by Glossopharyngeal Nerve Stimulation

Chemical Senses, 29,     

Biosynthesis of monosulfogangliotriaosylceramide and GM2 by N-acetylgalactosaminyltransferase from rat brain

Some properties of the enzyme activity that catalyzes the transfer of N-acetylgalactosamine from UDP-N-acetylgalactosamine to exogenous lactosylceramide-II3-sulfate (SM3) and N-acetylneuraminosyllactosylceramide (GM3) were studied using the enzyme preparation solubilized from the 100,000 X g pellet of 6-day-old rat brain. The products from SM3 and GM3 were identified as gangliotriaosylceramide-II3-sulfate (SM2) and N-acetylneuraminosylgangliotriaosylceramide (GM2), respectively, by TLC-autoradiography. Optimal conditions for both activities were similar: pH (Hepes-NaOH), 7.0-7.5; detergent (heptylthioglucoside), 0.64% and Mn2+, 5-10 mM. The concentrations of the detergent optimal for both enzyme activities were also examined at various concentrations of the acceptors. The lower the amounts of acceptors, the less the amounts of detergent that were required, and vice versa, for the maximum activities. The acceptor-saturation curve for SM2 synthesis was triphasic, exhibiting a sigmoidal region at lower concentrations, a hyperbolic region and finally a descending region. For GM2 synthesis, the curve was biphasic without the descending region. The donor-saturation curves were classical hyperbolic ones for both syntheses. The Km values calculated for SM3 and GM3 were 0.37 and 0.19 mM, respectively, when the data corresponding to the hyperbolic regions were used for the double-reciprocal plots. The Km values for UDP-N-acetylgalactosamine in the SM2- and GM2-synthesis were 82 and 26 microM, respectively. SM3 and GM3 were the best acceptors for this enzyme preparation. From the results of the acceptor competition study, it was suggested that the two synthetic reactions are catalyzed by a single enzyme.     

Conformational change of bovine serum albumin by heat treatment

The thermal denaturation of bovine serum albumin (BSA) was studied at pH 2.8 and 7.0 in the range of 2–65°C. The relative proportions of -helix, -structure, and disordered structure in the protein conformation were determined as a function of temperature, by the curve-fitting method of circular dichroism spectra. With the rise of temperature at pH 7.0, the proportion of -helix decreased above 30°C and those of -structure and disordered structure increased in the same temperature range. The structural change was reversible in the temperature range below 45°C. However, the structural change was partially reversible upon cooling to room temperature subsequent to heating at 65°C. On the other hand, the structural change of BSA at pH 2.3 was completely reversible in the temperature range of 2–65°C, probably because the interactions between domains and between subdomains might disappear due to the acid expansion. The secondary structure of disulfide bridges-cleaved BSA remained unchanged during the heat treatment up to 65°C at pH 2.8 and 7.0.     

Synthesis of acetone glycerol acyl esters by immobilized lipase ofMucor miehei

Summary The applications of immobilized lipase ofMucor miehei for the synthesis of acetone glycerol acyl ester from acetone glycerol and fatty acid, which is the first step for monoglyceride production was investigated. With a high oleic acid to acetone glycerol ratio (O/A, mol/mol), a high catalytic activity was observed under low water content in the reaction mixture. By the combination of high O/A ratio (>3) and removal of water which was produced during the reaction, the conversion degree was increased to almost 100%. With the O/A ratio of 3, the approximate half-life of the immobilized lipase and productivity of ester was estimated to be 20 days and 869 g product/g immobilized enzyme per 2 half-lives, respectively.