An arachidonic acid-specific lipoxygenase from the gorgonian coralPseudoplexaura porosa

Summary A novel lipoxygenase was partially purified from the gorgonian coralPseudoplexaura porosa and was found to be specific for arachidonic acid. This soluble enzyme catalyzed the formation of 15-hydroperoxy-eicosatetraenoic acid (15-HPETE) from arachidonic acid.This investigation was supported by PHS grant No. CA32395 awarded by the National Cancer Institute and by PHS Research Carreer Development Award No. ES00120 to MDC awarded by the National Institute of Environmental Health Sciences, DHHS. The authors acknowledge Ms M. A. Russell and Dr D. G. Anderson of the University of Miami for assistance in the collection of gorgonian corals. Preliminary work was conducted at the University of Miami School of Marine and Atmospheric Science. This is journal series No. 3638 from the Florida Agricultural Experiment Station.     

Naphthoquinones in defensive secretion of an opilionid

Summary The defensive secretion of the opilionidPhalangium opilio contains 1,4-naphthoquinone and 6-methyl-1,4-naphthoquinone. Naphthoquinones are of rate occurrence in arthropods, having previously been reported only from certain tenebrionid beetles.Paper No. 60 of the series: Defense Mechanisms of Arthropods.Acknowledgments. Partial support by the National Institutes of Health (grant Nos. AI-12020 and AI-02908, and fellowship award CA 05646 to D.F.W.) and the National Science Foundation (grant No. BMS 74-15084) is gratefully acknowledged. We thank Dr W.A. Shear for identifying the opilionid, and S. Daniels, K. Dodge, M. Guzewich and C. Smith for helping collect the specimens..     

Binding of actinomycin D and divalent cations to lipopolysaccharides ofAgrobacterium tumefaciens as studied by fluorescence spectroscopy

Summary The binding of actinomycin D and divalent cations to lipopolysaccharides ofA. tumefaciens was studied. Fluorimetric titrations revealed 2 binding sites (low and high affinity sites) for divalent cations, and 1 high-affinity site for actinomycin D.Acknowledgment. This project was financed by the Department of Science and Technology, Govt. of India (grant No. D.O. No.11 (19)/77-SERC). To whom reprint requests should be addressed.     

Growth promotion by extracts from Wilms' tumor in vitro

Zusammenfassung Anomale Komponenten, die aus Blutserum und Tumoren von Patienten mit Wilmschen Tumoren isoliert wurden, fördern das Wachstum der Nieren- und Lungenzellen-Kulturen.

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Supported by an institutional grant No. IN-21-I and IN-21-J from the American Cancer Society, N.I.H. training grant No. DE 00094-09 to L.A.B. from N.I.D.R., and N.I.H. Program Grant No. 5 POI DE 02848-02. We thank Mr.D. Beugelmans, MissP. Couture, and Mrs.Y. Takahashi for their excellent technical assistance, and Dr.Darleen Powars for the tumor samples.     

Cortinarius speciosissimus toxins — a preliminary report

Summary Methanolic extracts ofCortinarius speciosissimus yielded a fluorescent compound which was crystallized and shown to be a cyclic polypeptide. The compound, or an analogue, has been found in most members of the genusCortinarius.The authors acknowledge the help of Dr M. Stewart, Department of Biochemistry, Royal Infirmary, Glasgow, for the amino acid analysis. This work was supported by the Scottish Home and Health Department, grant No. H/MRS/S)/C350.     

Intermolecular and intramolecular isotope effects in the deamination of putrescine catalyzed by diamine oxidase

Summary The enzymatic deamination of 1,4-diaminobutane (putrescine) catalyzed by hog kidney diamine oxidase was studied with the aid of deuterium labeled substrates and mass spectrometry. An intermolecular deuterium isotope effect for the deamination of putrescine labeled with deuterium in all 4 alpha positions was observed to be 1.26. 1,4-Diaminobutane-1, 1-d₂ was synthesized and intramolecular isotope effects determined. The preference of diamine oxidase for the unlabeled alpha position was about 4 times greater than for the deuterated methylene. This work shows that intramolecular deuterium isotope effects are observable in enzyme systems other than cytochrome P-450.Acknowledgment. This investigation was supported by a research grant from the National Institutes of Health, grant number NS 14017.     

Effect of benzimidazole on nicotinamide adenine dinucleotide phosphate phosphomonosterase activity in wheat leaves

Summary Nicotinamide adenine dinucleotide phosphate phosphomonoesterase was isolated and partially purified from wheat (Triticum aestivum L. var. Selkirk) leaves. The enzyme hadK _NADP value of 1.4×10^–4 M and a pH optimum of 5.9.In vitro activity of this enzyme was unaffected by precursors of NAD (nicotinamide and nicotinic acid) or cytokinis (kinetin and benzimidazole). However, when detached wheat leaves were treated with solutions of these compounds, the precursors lowered the specific activity while the cytokinins enhanced the activity. It is suggested that spatial separation and compartmentation of the enzyme and its substrate NADP account for the similar effect of benzimidazole on both.This work was supported by a grant No. A2698 from the National Research Council, Canada.     

D-Amino acid oxidase: new findings

The most recent research on D-amino acid oxidases and D-amino acid metabolism has revealed new, intriguing properties of the flavoenzyme and enlighted novel biotechnological uses of this catalyst. Concerning the in vivo function of the enzyme, new findings on the physiological role of D-amino acid oxidase point to a detoxifying function of the enzyme in metabolizing exogenous D-amino acids in animals. A novel role in modulating the level of D-serine in brain has also been proposed for the enzyme. At the molecular level, site-directed mutagenesis studies on the pig kidney D-amino acid oxidase and, more recently, on the enzyme from the yeast Rhodotorula gracilis indicated that the few conserved residues of the active site do not play a role in acid-base catalysis but rather are involved in substrate interactions. The three-dimensional structure of the enzyme was recently determined from two different sources: at 2.5-3.0 A resolution for DAAO from pig kidney and at 1.2-1.8 A resolution for R. gracilis. The active site can be clearly depicted: the striking absence of essential residues acting in acid-base catalysis and the mode of substrate orientation into the active site, taken together with the results of free-energy correlation studies, clearly support a hydrid transfer type of mechanism in which the orbital steering between the substrate and the isoalloxazine atoms plays a crucial role during catalysis.     

Pre- and post-partum plasma amine oxidase differences in the rhesus monkey (Macaca mulatta)

Summary Plasma amine oxidase activity increased from 23.4 nmol/ml/h during pregnancy to 49.5 nmol/ml/h during an extended post partum period in 10 rhesus monkeys. Comparison with non-pregnant control monkeys sampled at similar times indicated that the significant differences were in the extended post partum period.We thank Dr.C. H. Conaway and Dr.J. D. Loy of the Caribbean Primate Research Center andJ. G. Vandenbergh andW. Post of the North Carolina Department of Mental Health for the use of their facilities and animals. We also acknowledge the technical assistance ofC. H. Donnelly andMs. Suzanne Baulu. This work was supported by a grant from Dr.H. C. Robinson, Jr., through Yale University Medical School and by NIH Contract No. 71-2003.     

Degenerative atrophy of central terminals of primary sensory neurons induced by blockade of axoplasmic transport in peripheral nerves

Summary Perineural colchicine- or vinblastine-treatment results in disappearance of non-lysosomal acid phosphatase activity, characterizing axon terminals in the Rolando substance of the normal spinal cord. Ultrastructural alterations are identical with those seen in the course of degenerative atrophy.Supported by research grant No. 4-01-0303-01-1 from the Hungarian Ministry of Health.     

Inhibition of DNA synthesis and cell division by actinomycin D

Zusammenfassung Nach in-vitro-Kultur oder Verwundung in vivo der Froschlinsen wird zuerst meistens, im Epithel, eine intensive DNS-Synthese gefunden auf die später zahlreiche Kernteilungsfiguren folgen. Nach Behandlung mit Actinomycin D werden diese Reaktionen stark gehemmt. Autoradiographische Untersuchungen mit dem DNS-Vorläufer H-3-Thymidin und dem RNS-Vorläufer H-3 Uridin erlauben den Schluss, dass die DNS-Synthese (und damit Zellteilung) von einer früheren RNS-Synthese abhängt.

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This work was supported in part by Public Health Service Grant No. NB-05425-01 and also by institutional grant 71D from the American Cancer Society.

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Supported by U.S. National Science Foundation grant No. GE-6534 5/410-0056.     

Changes in IAA oxidase activity in rooting hypocotyl cuttings ofPhaseolus mungo L.

Summary IAA oxidase activity increased concomitant with root initiation during 16–52 h, in all cultures, thus showing the necessity of an active IAA oxidase for root initiation inPhaseolus mungo hypocotyl cuttings. The increase being very sharp in IAA alone, but less in all other cultures. The role of sucrose in root initiation via IAA oxidase activity has been discussed.The research has been partly financed by a grant from the US Department of Agriculture. One of us (R.N.C.) is thankful to the CSIR, India, for financial assistance.     

Ceralbol,a new sesterterpenic alcohol isolated from insect wax

Summary The isolation and structural elucidation of ceralbol (1), a new sesterterpene from the insect waxCeroplastes albolineatus are reported.Contribution No. 465 from Instituto de Quimica de la Universidad Nacional Autonoma de Mexico.This work was supported by a grant from Syntex laboratories, S.A., Mexico, D.F.     

Amphiphilic spectroscopic probes utilizing metal chelates

Summary The synthesis and initial applications are reported for 1-[p-(pamitamido)-phenyl]ethylenedinitrilotetraacetic acid. The results demonstrate the versatility of this spectroscopic probe molecule, which allows achoice of a particular technique for a particular system as well as use of multiple spectroscopic techniques for complementary information about hydrophobic region in biological systems.This work was supported in part by grant No. CA-16861 from the National Cancer Institute, DHEW.     

Ca2+ uptake and distribution in alloxan-diabetic rat arterial and venous smooth muscle

Summary This report demonstrates that in experimental diabetes mellitus (DM) calcium uptake and its distribution is altered in rat aortic but not in portal venous smooth muscle. Results are interpreted as consequences of increased calcium binding by aortic smooth muscle in experimental DM, which could account for the hyporeactivity of alloxan diabetic rat aorta reported previously.Supported by NIH grant No.HL-18015 and NIDA grant No. DA-02339.     

Evaluation of models for the mechanism of action of 4-hydroxyphenylpyruvate dioxygenase

Summary 4-Hydroxyphenylpyruvic acid was oxygenated with various complexes of oxygen with Fe²⁺, superoxide ion, hydroperoxide anion, triplet and singlet oxygen. Oxidation occurred giving varying amounts of the 4-hydroxy derivatives of benzaldehyde, benzoic acid, phenol, phenylacetic acid and 4-carboxymethylquinone, but no homogentisic acid. 4-Hydroxyphenylperacetic acid was prepared and shown not to undergo self-oxidation. Its ferrous salt decomposed to 4-hydroxybenzyl alcohol. It is concluded that thea-keto carboxylic function is the site of oxygenation in the enzyme process and that a trioxalanone rather than a peracid intermediate may be implicated.Acknowledgments. We thank a referee for drawing our attention to the work of Hawkinsin and we are indebted to the Swiss National Science Foundation for the support of this work (grant No 2.418.0.79).     

Octopamine and proctolin mimic spontaneous membrane depolarisation inLucilia larvae

Summary Octopamine and proctolin at concentrations below 10^–8 M reversibly induce a spontaneous rhythmic depolarization which occurs in body-wall muscles ofLucilia larvae. The effect appears to be postsynaptic and mediated by receptors specific for each substance.This work was supported by NIEHS grant No. ES00814 and EPA grant No. R804345.     

Estrogen action in the male

Summary Estrogen administration induces a migration of eosinophil leukocytes to ductus deferens.Acknowledgments. This work was supported by grant No. 4002 from the Servicio de Desarrollo Científico y Creación Artística of the University of Chile. We thank Mr D. Sáez and Mr E. Astudillo for technical help.     

Immunochemical studies onRhodotorula gracilis D-amino acid oxidase

Summary Polyclonal antibodies were prepared from rabbit sera after immunization with holo- and apo-D-amino acid oxidase purified fromR. gracilis. Both anti-holo- and anti-apoenzyme IgG fractions (as well as affinity-purified IgG) were highly specific: in blot-transfer analyses after SDS-PAGE only a 39 kDa band, corresponding to enzyme monomer, was recognized even in the partially purified yeast extract. No cross-reaction was detected with pig kidney D-amino acid oxidase. As a difference from the mammalian enzyme, yeast D-amino acid oxidase anti-holo- and anti-apoenzyme IgGs had different properties in inactivation and precipitation experiments, indicating the existence of different antigenicity sites related to the FAD-binding domain in the enzyme.