Isolation and Identification of Lutein from Lemna paucicostata 381 as an Inhibitor of Benzoic Acid-induced Flowering in Lemna paucicostata 151

Efforts were made to isolate flower-inhibitory substances from extracts of the short-day plant Lemna paucicostata 381. Lemna paucicostata 151, which was used in the bioassay, exhibits poor flowering in response to the photoperiod, but flowers profusely in response to benzoic acid. Therefore, only those substances that inhibit benzoic acid-induced flowering were studied. Several fractions obtained by silica gel column chromatography exhibited flower-inhibitory activity when tested on L. paucicostata 151. After several purification steps, one of the active principles was identified as lutein by MS, UV and NMR spectroscopic analyses. Lutein and its isomer zeaxanthin inhibited benzoic acid-induced flowering in both L. paucicostata 151 and 381.     

Mutagenicity of Hydroperoxides of Fatty Acids and Some Hydrocarbons

Three phytotoxins named pyrenochaetic acids A, B and C were isolated from culture filtrates of Pyrenochaeta terrestris, and the structures were determined to be 4-crotonoyl-3-methoxy-5-methylbenzoic acid (I), 4-(3-hydroxybutyroyl)-3-methoxy-5-methylbenzoic acid (II) and 4-butyroyl-3-methoxy-5-methylbenzoic acid (III), respectively. Their phytotoxicities were demonstrated in bioassays.     

ESR spectral changes induced by chlorpromazine in spin-labeled erythrocyte ghost membranes

chlorpromazine interacted preferentially with membrane proteins rather than membrane lipids in the initial incorporation into human erythrocyte ghosts, as demonstrated by means of the fluorescence quenching and a maleimide spin label. In this state the membrane fluidity increased. At higher concentrations of chlorpromazine, the membrane fluidity decreased and a motionally restricted signal from fatty acid spin labels appeared predominantly. However, no such signal appeared in protein-free vesicles. The temperature and pH dependences of the outer hyperfine splitting of this restricted signal were very similar to those of bovine serum albumin. On the basis of sodium dodecyl sulfate-polyacrylamide gel electrophoresis of chlorpromazine-treated and -untreated ghosts, it was found that there was no significant difference in membrane proteins between both samples except for the changes of a few bands which were not directly concerned with the occurrence of this restricted signal. These results suggest that the fatty acid spin labels bind preferably to membrane proteins as the lipid domain becomes packed with chlorpromazine.     

Purification and characterization of the flagellar hook-basal body complex of Salmonella typhimurium.

The hook-basal body complex of Salmonella typhimurium, a major component of its flagellar apparatus, was subjected to detailed analysis by electron microscopy and gel electrophoresis. The study was facilitated by the development of an improved protocol for isolation of the complexes in high yield and purity. Nine proteins were identified with the structure. These proteins had apparent molecular weights of 65,000 (65K), 60K, 42K, 38K, 32K, 30K, 27K, 16K, and 14K. Small but reproducible shifts in the apparent molecular weights of specific proteins from conditionally nonflagellate mutants indicated the following gene-polypeptide correspondences: flaFV, 42K; flaFVI, 32K; flaFVII, 30K; flaFIX, 38K; flaAII.1, 65K. Several new morphological features of hook-basal body complexes were recognized, including a clawlike structure on the cytoplasm-proximal M ring and additional material at the cytoplasmic face of the M ring. Based on this study and the work of others, we suggest that the morphological features of the hook-basal body complex correspond to the following proteins: hook-filament junction, 60K; hook, 42K; rod, 30K and 32K; L ring and outer cylinder wall, 27K; P ring, 38K; S ring, unknown; M ring 65K.     

Stability and localization of biotin-labeled murine monoclonal antibody to human gastric cancer in normal mice and nude mice-human tumor models

We examined the tissue localization of biotin-labeled murine monoclonal antibody (MAb) S202 directed against the human scirrhous gastric carcinoma cell line MK-01 in normal and tumor-bearing mice after intravenous (IV) administration. The biotin-labeled MAb proved to be stable in vivo under normal conditions, antibody titer being 1:256 at 4 hr after IV injection. At 24 hr after injection, the tumor was stained by the avidin-biotin-peroxidase complex (ABC) method. Biotin-labeled MAb was found to be suitable for detection of the xenografted tumor of nude mice. This study provides new information concerning the dynamics of the distribution of biotin-labeled MAb in vivo.     

Distribution of IL-5 receptor-positive B cells. Expression of IL-5 receptor on Ly-1(CD5)+ B cells.

mAb to murine IL-5R were prepared by means of fusion between mouse myeloma cells and spleen cells from a rat immunized with membrane-enriched fractions of IL-5-dependent early B cell line (T88-M). Two mAb (H7 and T21) were selected for their competitive inhibition of receptor binding by 35S-labeled IL-5 and of IL-5 biologic activities. The number of binding sites recognized by the mAb on different cell lines correlated with IL-5 responsiveness. Most surface IgM+ peritoneal B cells were H7+ and more than 70% were also Ly-1(CD5)dull+, and responded to IL-5 for polyclonal IgM production in a high frequency. A significant proportion of splenic B cells reacted with these mAb, although lower number (one-log less) than peritoneal B cells and a small proportion of H7dull+ splenic B cells seems to be Ly-1(CD5)dull+, 1 of 200 splenic B cells responded to IL-5 for IgM production. These results suggest that IL-5R+ B cells may consist of a subpopulation of B cells. Intriguingly, lymphoid populations of bone marrow cells were stained with H7 and T21, whereas myeloid populations were brightly stained with only T21. Finally, both H7 and T21 mAb specifically precipitated a protein of a Mr 60,000 from 125I-labeled cell lysates of IL-5R+ T88-M cells. The IL-5R with similar size (Mr 55,000 to 60,000) was precipitated from the cell lysates of peritoneal B cells. T21 mAb but not H7 mAb precipitated a protein of a Mr 110,000 from the cell lysates of bone marrow cells.     

Selective Increase in S-100β Protein by Aging in Rat Cerebral Cortex

Changes in the concentrations of nervous tissue-related proteins and their isoproteins, such as S-100 proteins (S-100 alpha and S-100 beta), enolase isozymes (alpha-enolase and gamma-enolase), and GTP-binding proteins (Go alpha, Gi2 alpha, and beta-subunits), were determined in the CNS of male rats of various ages (from 2 to 30 months old) by means of enzyme immunoassay. The weights of brains and the concentrations of soluble proteins in the cerebral cortex, cerebellum, and brainstem were constant during the observation period. The concentration of S-100 beta protein, which is predominantly localized in glial cells, increased gradually in the cerebral cortex with age; levels in the 25-month-old rats increased to approximately 150% of the levels in the young (2-month-old) rats. However, the S-100 beta concentrations in the cerebellum and brainstem were relatively constant, showing similar values in rats 2-30 months old. Levels of other proteins, including both neuronal (gamma-enolase and Go alpha) and glial (alpha-enolase and S-100 alpha) marker proteins, did not change significantly with age in the cerebral cortex, cerebellum, and brainstem. These results suggest that there is a close relation between the age-dependent changes of the CNS function and S-100 beta protein levels in the cerebral cortex.     

Expression of the blasticidin S deaminase gene (bsr) in tobacco: Fungicide tolerance and a new selective marker for transgenic plants

Summary Blasticidin S (BS), a fungicide of microbial origin, is used for the practical control of rice blast disease. It has broad antimicrobial activity but occasionally exhibits adverse phytotoxic effects on some dicot plants. An inactivating enzyme, BS deaminase, was discovered in the BS resistant strain, Bacillus cereus K55-S1, and the structural gene, bsr, for the enzyme has been cloned. We introduced the bsr gene into tobacco plants using the Ti plasmid vector system and demonstrated that the bsr gene conferred a BS resistant phenotype to the plants. Thus the bsr gene could be useful as a selective marker for plant transformation and provides an example for a new approach to the solution of phytotoxicity problems associated with the use of some types of fungicide.     

ESR spectral changes induced by chlorpromazine in spin-labeled erythrocyte ghost membranes

Chlorpromazine interacted preferentially with membrane proteins rather than membrane lipids in the initial incorporation into human erythrocyte ghosts, as demonstrated by means of the fluorescence quenching and a maleimide spin label. In this state the membrane fluidity increased. At higher concentrations of chlorpromazine, the membrane fluidity decreased and a motionally restricted signal from fatty acid spin labels appeared predominantly. However, no such signal appeared in protein-free vesicles. The temperature and pH dependences of the outer hyperfine splitting of this restricted signal were very similar to those of bovine serum albumin. On the basis of sodium dodecyl sulfate-polyacrylamide gel electrophoresis of chlorpromazine-treated and -untreated ghosts, it was found that there was no significant difference in membrane proteins between both samples except for the changes of a few bands which were not directly concerned with the occurrence of this restricted signal. These results suggest that the fatty acid spin labels bind preferably to membrane proteins as the lipid domain becomes packed with chlorpromazine.