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

Chemical Senses, 29,     

Purification of Protein Body-I of Rice Seed and its Polypeptide Composition

Protein body type one (PB-I) was isolated and purified fromdeveloping rice grain by a combination of sucrose density gradientcentrifugation and treatment with pepsin. SDS-PAGE analysisshowed that isolated PB-I contains several polypeptide groups,the largest having an apparent molecular size of 13 kDa andtwo smaller ones of 10 kDa and 16 kDa. The 13-kDa group wasfound to be composed of two polypeptides of slightly differentmolecular sizes, 13a (larger component) and 13b (smaller component).Most of the 13a and 13b polypeptides were shown to be largelyprolamins, although there were also some salt- and alcohol-insolublepolypeptides with an apparent molecular size of 13 kDa. It wasconcluded that PB-I is the accumulation site of rice prolamin.It was further estimated that the protein amount in PB-I accountedfor about 20% of the total protein of rice endosperm. (Received March 20, 1987; Accepted September 8, 1987)     

Measurement of Serine Acetyltransferase Activity in Crude Plant Extracts by a Coupled Assay System Using Cysteine Synthase

Serine acetyltransferase (SATase) (EC 2.3.1.30 [EC] ) catalyzes theformation of Oacetyl-L-serine (OAS) from L-serine in the presenceof acetyl-CoA. A novel assay method was developed for measuringthis enzyme activity in extracts from plant tissues. The assayconsists of a coupled system in which the OAS formed is convertedto cysteine by the addition of cysteine synthase (CSase) (EC4.2.99.8 [EC] ). Cysteine thus formed is determined colorimetricallyand serves as a measure for SATase activity. This method israpid, simple and sensitive, and can be readily adapted formeasurement of SATase activity in crude tissue extracts or homogenates. (Received January 14, 1987; Accepted April 27, 1987)     

Modification in Cell Shape Unrelated to Cellulose Microfibril Orientation in Growing Thallus Cells of Chaetomorpha moniligera

Cellulose microfibril orientation patterns in thallus cellsof Chaetomorpha moniligera were studied, and the relationshipbetween the microfibril and the peripheral microtubule arrangementsduring cell-shape modification by colchicine was examined. Inthe cuttings from growing thalli, linearly arranged cylindricalcells developed into cask-shaped cells during 4–6 daysof culture at 27?C. In the cylindrical cells, microfibrils formingthe innermost portion of the wall were arranged alternatelyin longitudinal and transverse directions, but peripheral microtubuleswere always arranged only in a longitudinal direction. Thesefeatures were also noted in the cask-shaped cells. Colchicineat 10^–3M and 3?10^–3M accelerated both cell expansionand wall thickening with matrix deposition, but the directionsin which both microfibrils and microtubules were arranged werethe same as those of the cylindrical cells. These results indicatethat (1) the microfibril and microtubule arrangements of Chaetomorphaare not necessarily correlated, (2) changes in cell shape ofChaetomorpha are not necessarily accompanied by changes in thearrangement of cell-wall microfibrils, and (3) colchicine playsa role in the loosening and thickening of cell walls by enhancingmatrix deposition. (Received June 2, 1986; Accepted February 13, 1987)     

Evolutionary relationships between laboratory mice and subspecies of Mus musculus based on the genetic study of pancreatic proteinase loci,Prt-1, Prt-2, Prt-3, and Prt-6

Various patterns of mouse pancreatic proteinase activity bands were observed on agarose gel electrophoresis. Prt-1 ^a and Prt-1 ^b genes control the positive (PRT-1A) and negative (PRT-1B) expression of tryptic band V, respectively; Prt-2 ^a and Prt-2 ^b correspond to chymotryptic bands II (PRT-2A) and III (PRT-2B); Prt-3 ^a and Prt-3 ^b control the low (PRT-3A) and high (PRT-3B) tryptic activities of band IV; the Prt-1 and Prt-3 loci are closely linked on the same chromosome; Prt-6 ^a and Prt-6 ^b correspond to tryptic bands I (PRT-6A) and I (PRT-6B). Twenty-four laboratory strains from the United States showed the phenotype PRT-1A, PRT-3A, and PRT-2A. Of laboratory strains established in Europe, 6 showed PRT-1A, PRT-3A, and PRT-2A, and 10 had PRT-1B, PRT-3A, and PRT-2A bands. Most wild mice around the world and their descendants showed the phenotype PRT-1B, PRT-3B, and PRT-2A. Only the phenotype of M. m. brevirostris was PRT-1A, PRT-3A, and PRT-2A, which was the same as most laboratory inbred strains. PRT-2B was observed mainly in Japanese (M. m. molossinus) and Korean (M. m. yamashinai) wild mice. PRT-6B was detected only in Mus spicilegus and Mus caroli, but all other mice including wild populations and laboratory strains showed PRT-6A. New biochemical phenotypes such as PRT-2C and PRT-3C were also found in this study.     

Di(2-ethylhexyl)phthalate enhances hepatic phospholipid synthesis in rats

The effects of di(2-ethylhexyl)phthalate, a typical peroxisomal proliferator, on the activities of key enzymes in the glycerophospholipid synthetic pathway and the incorporation of lipid precursors into liver lipids in vitro were studied periodically in rats. When di(2-ethylhexyl)phthalate was fed at the 1% level to rats, glycerol-3-phosphate acyltransferase activity increased 2-3-fold in liver homogenates and microsomes in 2-4 days. The specific activity of microsomal CTP:phosphocholine cytidylyltransferase increased by 1.5-fold, whereas the cytosolic activity was depressed. The microsomal CDPcholine:diacylglycerol cholinephosphotransferase specific activity decreased, whereas the activity in the homogenates increased, suggesting the proliferation of the hepatic endoplasmic reticulum in di(2-ethylhexyl)phthalate-treated rats. The incorporation of [1(3)-3H]glycerol or [1-14C]acetate into liver phospholipids in vitro increased in 2 days and stayed at a high level up to 12 days. The present study confirmed that di(2-ethylhexyl)phthalate induced an enhancement of phospholipid synthesis in the liver. The increase in hepatic phospholipid synthesis by this drug is presumably linked to the proliferation of peroxisomes and other intracellular membranes.