Some Properties of the Arginine Decarboxylase in Vicia faba Leaves

Growth of Vicia faba seedlings is accompanied by a rapid increasein arginine decarboxylase (EC 4.1.1.19 [EC] ) in the leaves and epicotyl.Increased enzyme activity was observed under saline conditionsin the presence of NaCl and with osmotic stress by mannitol.The partially purified enzyme (about 86-fold) readily decarboxylatedL-arginine, while D-arginine, L-homoarginine, L-ornithine andL-lysine were decarboxylated very slowly, and L-citrulline andL-glutamic acid were not decarboxylated. The K_m value was 5.8?10^–4M for L-arginine. The optimal pH and temperature for activitywere 8.5 and 45?C, respectively. p-Chloromercuribenzoate andN-ethylmaleimide were effective inhibitors of the enzyme. Inhibitionby spermidine, putrescine and agmatine suggested a possiblefeed-back mechanism in the pathway of polyamine biosynthesis. (Received October 11, 1983; Accepted February 24, 1984)     

In vivo and in vitro studies on the appearance of LHRH neurons in the hypothalamus of perinatal rats

Summary Ontogenetic development of LHRH-containing neurons was studied by fluorescence and enzyme immunohistochemistry in rats. In in vitro studies, the tissues of the septal-chiasmatic and mediobasal hypothalamic areas of fetal rats on day 16.5 or 18.5 of gestation were trypsinized separately for dissociation of the neural cells, and cultured for several days. Immunopositive reaction against LHRH was first detected in nerve cells derived from both areas of the hypothalamus of the fetuses on days 16.5 and 18.5 of gestation, after 8 and 6 days culture, respectively. The cells were small, and seemed to be bipolar in morphology indicating an axon and arborized dendrites. Immunopositive material occurred in the cell soma as well as in the cellular processes. In in vivo studies, immunopositive material, possibly deposited in nerve fibers, appeared first in OVLT and simultaneously in the external layer of the median eminence of fetuses on day 20.5 of gestation. The immunoreactive fibers increased in number in both parts with development, especially after birth in the median eminence. No immunopositive material was detected within any neural cell bodies nor in the cytoplasm of any ependymal cells.This work was financed by the Ministry of Education, Japan. No. 257008. We would like to thank Dr. Katsuhiko Saito (Department of Surgery, Tokushima University) for his kind advice on the preparation of the antibody used for the immunofluorescence study.     

Immunological study of the regulation of cellular arylsulfatase synthesis in Klebsiella aerogenes.

Regulation of cellular arylsulfatase synthesis in Klebsiella aerogenes was analyzed by immunological techniques. Antibody directed against the purified arylsulfatase from K. aerogenes W70 was obtained from rabbits and characterized by immunoelectrophoresis, double-diffusion, quantitative precipitation, and enzyme neutralization tests. Arylsulfatase was located in the periplasmic space when the wild-type strain was cultured with methionine or with inorganic sulfate plus tyramine, but not with inorganic sulfate without tyramine, as the sole sulfur source. Tyramine oxidase was retained in the membrane fraction prepared from cells grown in the presence of tyramine. Arylsulfatase protein was not synthesized in the presence of tyramine and inorganic sulfate by mutant K611, which is deficient in tyramine oxidase (tynA). We conclude that the expression of the arylsulfatase gene (atsA) is regulated by the expression of tynA and that inorganic sulfate serves as a corepressor. In addition, strains mutated in the atsA gene were analyzed by using antibody.     

Correlation between effects of 24 different cytochalasins on cellular structures and cellular events and those on actin in vitro

To compare the effects of cytochalasins on the cellular level with those on the molecular level, 24 cytochalasins, 20 natural compounds and 4 derivatives, were used. The following effects were tested for each of 24 cytochalasins; (a) four high dose (2-20 muM) effects on the cellular level: rounding up of fibroblastic cells, contraction of actin cables, formation of hairy filaments containing actin, and inhibition of lymphocyte capping; (b) a low dose (0.2-2 muM) effect: inhibition of membrane ruffling; and (c) two in vitro effects: an inhibition of actin filament elongation (the high affinity effect [low dose effect] in vitro) and an effect on viscosity of actin filaments(the low affinity effect [high dose effect] in vitro). These results indicated that there are almost the same hierarchic orders of relative effectiveness of different cytochalasins between low and high dose effects and between cellular and molecular effects. From the data obtained with the 24 cytochalasins, we have calculated correlation coefficients of 0.87 and 0.79 between an effect in vivo, inhibition of capping, and an effect in vitro, inhibition of actin filament elongation, as well as between inhibition of capping and another effect in vitro, effect on viscosity of actin filaments, respectively. Furthermore, a correlation coefficient between the high affinity effect and the low affinity effect determined in vitro was calculated to be 0.90 from the data obtained in this study. The strong positive correlation among low and high dose effects in vivo and those in vitro suggests that most of the effects caused by a cytochalasin, irrespective of doses or affected phenomena, might be attributed to the interaction between the drug and the common target protein, actin. In the course of the immunofluorescence microscope study on cytochalasin-treated cells using actin antibody, we have found that aspochalasin D, a 10-isopropylcytochalasin, strongly induced the formation of rodlets containing actin in the cytoplasm of the treated fibroblasts. In contrast, the other cytochalasins, including cytochalasin B, cytochalasin C, cytochalasin D, and cytochalasin H, were found to induce the formation of nuclear rodlets. Both cytoplasmic and nuclear rodlets found in the cytochalasin-treated cells were similar in ultrastructures to those induced by 5 to 10 percent (vol/vol) dimethyl sulfoxide in the same type of cells.     

Internal ultrastructure of spores of microsporidans isolated from the Silkworm,Bombyx mori

Nosema bombycis, two Nosema spp., and a Pleistophora sp. were propagated in the silkworm and the fine structures of their spores were studied. The morphology of the polaroplast, the appearance of the nucleus, and the number of coils in the polar filament differed among the spores of the four species. The spores of the three Nosema species, however, had several identical components; e.g., the polaroplast was made up of two parts, they had two nuclei, and the ribosome arrangement was similar. On the other hand, the spore of Pleistophora sp. had a polaroplast composed of three parts, a single nucleus, and ribosomes arranged around the polar filament. Thus the fine structures of the spore differentiate microsporidan species.     

Volatile components of Artemisia capillaris

Terpenoid and acetylenic components not reported previously in Artemisia capillaris have been identified, including p-cymene, 5-phenyl-1, 3-diyne, dehydrofalcarinone and dehydrofalcarinol. The distribution of volatile components in different parts of the plant is described.     

Studies on antiviral glycosides. II. Mode of action for virucidal effects on Sendai virus

Treatment of Sendai virus with $\text{p-(sec-}\text{butyl)-phenyl-6-chloro-6-deoxy-β-}\text{d}\text{-glucopyranoside}$, followed by freezing and thawing resulted in a loss of hemolytic and cell fusion activities as well as infectivity without affecting hemagglutinating and neuraminidase activities. The anti-hemolytic activity of this compound was reversed by the addition of phosphatidyl choline to the virus samples. $\text{p-}\text{Azidophenyl-6-chloro-6-deoxy-β-}\text{d}\text{-[}{}^3\text{H]glucopyranoside}$ was successfully used for photoaffinity labeling of a specific virion site, and we confirmed the affected site of the glucoside to be the lipid components in the viral envelopes.     

A specific concanavalin A-mediated binding of bovine serum α-mannosidase to cultured human skin fibroblasts

A specific elevation of cell-associated α-mannosidase was observed in human skin fibroblasts cultured with concanavalin A for 12–72 hours. There was a latency of several hours before the increase of the enzyme activity occurred. When the cells were washed with α-methylmannoside, α-mannosidase activity was not increased. Other lysosomal enzymes including β-mannosidase showed a slight decrease in activity. It was concluded that the elevation of this enzyme activity was the result of a specific binding to the cell surface mediated by concanavalin A.     

A search for the indianapolis-variant of human alcohol dehydrogenase in liver autopsy samples from North Germany and Japan

Summary Human liver alcohol dehydrogenase (ADH) variants were screened in random autopsy specimens from 53 North German and 34 Japanese individuals. Based on pH-activity profile and electrophoretic pattern, only ADH₂ and ADH₃ variants were detected. In relatively fresh specimens, an anodic band or -ADH band was also observed. The recently reported new molecular forms collectively called ADH_Indianapolis (Bosron et al. 1980) could not be demonstrated and therefore may be confined hitherto only to the American black population.This paper is dedicated to Professor Dr. Dr. H. Baitsch on his 60th birthday     

Culture of chlorophyllous tobacco-cells not requiring any organic additives except sucrose in the medium I. Effects of light and temperature on the growth of the cells

1. In the dark, HNG (habituated Nicotiana glutinosa) and NG cellsscarcely grew at 15?C, and the difference between the growthrates of HNG and NG was small at both 15?C and 25?C.
2. The stimulatoryeffect of light (4000 lux) on the cell growthrate was higherat 25?C than at 15?C for both HNG and NG.
3. Light exerted muchmore effect on the growth rate of HNG thanof NG.
4. The thermaleffect was higher in the light than in the darkfor both HNGand NG, and was somewhat greater on NG than onHNG.
5. The synergisticeffect of light and temperature on cell growthwas greater onHNG than on NG.
6. HNG contained more chlorophyll than NG.
7. Inaddition, there was little difference between the friabilitiesof cell groups of HNG and NG.

(Received December 3, 1976; )