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)     

An 83-kDa embryonic-type nuclear antigen is detected within the germinal vesicles of oocytes of the ascidianHalocynthia roretzi

Summary Monoclonal antibodies were raised against germinal vesicles which were isolated from fully grown oocytes of the ascidianHalocynthia roretzi. Immunoblot analyses revealed that one of the antibodies, designated Hgv-2, recognized a single band with a molecular weight of about 83 kDa. The antibody, visualized by indirect immunohistochemistry, reacted only with the germinal vesicles of oocytes and did not react with test cells, follicle cells, and other somatic cells of the gonad. During embryogenesis the antigenicity was found in interphase nuclei of all embryonic cells. The antibody did not react with chromosomes or the mitotic apparatus. The antigenicity was retained by interphase nuclei of larval cells, but it disappeared from nuclei of juveniles about 7 days after metamorphosis.     

Regional localization of the LCA oncogene to human chromosome region 2q14----q21

A novel human oncogene, LCA, was assigned to region 2q14----q21 by in situ molecular hybridization. The present regional mapping substantiates the previous assignment that was performed by Southern blot analyses of DNAs from flow-sorted human chromosomes and human-mouse somatic cell hybrids.     

A new model of counterion condensation in polyelectrolyte solutions. III. Theoretical predictions of competitive condensation between counterions of different valences

Our model has been extended for theoretical estimation of competitive condensation of counterions of different valences onto polyelectrolytes in solution. The estimations are compared with those obtained from Manning theory and with experimental data on counterion activity coefficients. The agreement with the data for sodium polystyrenesulfonate/MgCl2, CaCl2 is satisfactory.     

Atropine inhibits the degranulation of Paneth cells in ex-germ-free mice

Summary Previous studies have shown that the secretory products of Paneth cells contain antibacterial agents (lysozyme, IgA) that are affected by the bacterial milieu in the intestine. To investigate whether Paneth-cell secretion is controlled via cholinergic mechanisms, the ultrastructure of Paneth cells was studied in four animal groups: (1) germfree (GF) control mice (Jcl: ICR [GN], male, 13 weeks old), (2) GF mice injected subcutaneously with atropine sulfate (200 mg/kg body weight, dissolved in physiological saline 20 mg/ml), (3) ex-GF mice inoculated with feces from specific-pathogen-free (SPF) mice, and (4) ex-GF mice injected with atropine and inoculated with feces from SPF mice. In ex-GF mice inoculated with feces, 70–90% of the Paneth cells showed fewer secretory granules than those from GF mice (p<0.01). Approximately 30% of the Paneth cells had a large vacuole (3–10 m diameter) in the apical cytoplasm. Exocytosed electron-dense material from secretory granules was observed in a few crypt lumens. In ex-GF mice inoculated with feces and given atropine, about 90% of the Paneth cells contained numerous secretory granules, like those in GF control mice, but vacuolated Paneth cells and exocytotic figures were rare; thus the secretion of Paneth cells was blocked by atropine. It is therefore possible that the bacterial milieu in the intestine affects the secretory activity of Paneth cells via cholinergic mechanisms.     

Isolation and Characterization of a Photosystem II Core Complex Depleted in the 43 kDa-Chlorophyll-Binding Subunit

The photosystem II core complex purified from digitonin extractsof spinach chloroplasts was resolved into two chlorophyll-proteincomplexes by digitonin polyacrylamide gel electrophoresis aftertreatment with 1 M potassium thiocyanate. One of the chlorophyll-proteincomplexes resolved consisted of 47, 32, 30 and 9 kDa polypeptidesand the other was complementally composed of only the 43 kDapolypeptide. The former complex was highly active in the photoreductionof 2, 6-dichlorophenol indophenol by 1,5-diphenylcarbazide andretained all of the components responsible for the electrontransport from the secondary electron donor (Z) to the primaryelectron acceptor (Q_A). EPR signal II_fast and II_slow were alsopreserved in this complex although their hyperfine structureswere largely modified. The complex was estimated to contain1.8 molecules of plastoquinone A as well as 1.5, 3.7 and 3.9molecules of cytochrome b559, pheophytin and ß-carotene,respectively, per Q_A. These results indicate that potassiumthiocyanate specifically removes the 43 kDa polypeptide fromthe PS II core complex leaving the electron transport systemin an almost intact state. (Received June 17, 1987; Accepted October 23, 1987)     

Ion Effects on the H+-Translocating Adenosine Triphosphatase and Pyrophosphatase Associated with the Tonoplast of Chora corallina

H⁺-translocating ATPase and pyrophosphatase (PPase) associatedwith the tonoplast of Chara corallina were isolated with theaid of a perfusion technique, and the effects of ions on theiractivities were studied. All the alkali metal cations testedstimulated the ATPase and ATPdependent H⁺ pumping activitiesonly by 10 to 40%. Anions, on the other hand, strongly affectedthe activities. Potassium salts of Cl^- and Br^- stimulated them,while F^- and NO₃^- inhibited them. By contrast, the H⁺-translocatingPPase was insensitive to anions but sensitive to cations. Theorder of cation stimulation was Rb⁺=K⁺>Cs⁺>Na⁺=Li⁺>choline⁺.NO₃^- (50 mil), thought to be a specific inhibitor of the tonoplast-typeH⁺-ATPase, inhibited the ATPdependent H⁺ pumping almost completelybut the ATPase activity by only about 50%. Na⁺ inhibited thePP₁-dependent H⁺ pumping (I_5O=5OmM) in the presence of 50 mMKCl but not the ATP-dependent one. The PPase was more sensitiveto F^- (I₅₀=400µM) than the ATPase. Both the H⁺-ATPaseand the H⁺-PPase required Mg²⁺ for their activities, althoughan excess was inhibitory to both. The different sensitivitiesof the PP₁-dependent and the ATP-dependent H⁺- pumping enzymesto ions correspond to the tonoplast enzymes of higher plantsand may be used as "markers" to distinguish between these enzymesin characean cells (Received October 2, 1987; Accepted May 18, 1988)     

Chromosomal location of genes conditioning low amylose content of endosperm starches in rice,Oryza sativa L.

Summary Eight dull mutants that lower the amylose content of rice endosperm as well as waxy mutant and a cultivar with common grains were crossed in a diallele manner. The amylose content of F₁ and F₂ seeds was determined on the basis of single grain analysis. It was concluded that the low amylose content of dull mutants is under monogenic recessive control. Alleles for low amylose content are located at five loci designated as du-1, du-2, du-3, du-4 and du-5. These loci are independent of wx locus located on chromosome 6. The five du loci have an additive effect in lowering the amylose content. Two loci, du-1 and du-4, were found to be located on chromosomes 7 and 4, respectively.