Factors affecting high-frequency fungal protoplast fusion

Summary Factors influencing the fusion frequency of protoplasts have been examined with auxotrophic mutants ofAspergillus nidulans. The optimum conditions were a total of 5 to 15 million protoplasts per ml, and 25% polyethylene glycol (PEG) 4000 or 6000 as fusogenic agent in 10 to 100 mM CaCl₂ solution.     

In vitro radiolabeling of galactosyl and N-acetylgalactosaminyl moieties of glycoproteins with carbon-14

Summary The primary alcohol group on the carbon 6 of terminal galactosyl and N-acetylgalactosaminyl moieties of glycoproteins can be oxidized to an aldehyde by treatment with galactose oxidase. By reacting these aldehyde groups with¹⁴C-labeled sodium cyanide,¹⁴C-labeled cyanohydrin derivatives were obtained. Similarly, reduction of these aldehyde groups with tritiated sodium borohydride following standard procedures, yields³H-labeled glycoproteins.¹⁴C- and³H-labeled derivatives of asialofetuin and asialo ovine submaxillary mucin with high specific radioactivities were prepared using these procedures. Mixtures containing microgram amounts of¹⁴C- and³H-labeled glycoproteins were subjected to column chromatography and gradient ultracentrifugation and the position of the individual glycoproteins was determined by simultaneous counting for¹⁴C and³H. These experiments demonstrate the usefulness of this approach for comparative analytical studies using biological specimens available in minute quantities.     

Purification and properties of glutamine synthetase I fromRhizobium sp. UMKL 20

Summary Glutamine synthetase I was purified fromRhizobium sp. UMKL 20 following polyethylene glycol precipitation. The enzyme had a subunit molecular weight of 58 kd. Apparent K_m values for ammonia and glutamate were 5.6 and 15.2 mM, respectively. Glutamine synthetase I activity was inhibited by several end products of glutamine metabolism. The purified enzyme was highly adenylylated (E _n ^– =8.5).Acknowledgment. I would like to thank Mr J. C. Lai for technical assistance. This work was carried out with the support of Vote F 153/79 from the University of Malaya.     

The role of glycine in the biosynthesis of steroids

Zusammenfassung Während der Biosynthese von Cholesterol mit homogenisierter Rattenleber wird [2-¹⁴C] des Glycins viel besser eingebaut als [1-¹⁴C].Saccharomyces cerevisiae produziert radioaktives Squelen (ausser Ergosterol mit Radioaktivität des Ringsystems) mit [2-¹⁴C] Glycin und mit [3-¹⁴C] Serin, aber nicht mit [1-¹⁴C] Glycin.

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Studies on Biosynthesis. Part VI. For Part V, seeA. K. Bose, K. S. Khanchandani andB. L. Hungund, Experientia,27, 1403 (1971). b) Presented at the 164th National Meeting of the American Chemical Society, New York, August, 1972.

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The support of this research by Stevens Institute of Technology and Sandoz Foundation is gratefully acknowledged. We wish to thank Drs.P. T. Funke, M. S. Manhas, P. K. Bhattacharyya, M. Anchel andH. Levey for valuable discussions and help with some of the experiments.     

Aberrant,canavanyl protein formation and the ability to tolerate or utilize L-canavanine

Summary L-Canavanine, 2-amino-4-(guanidinooxy)butyric acid, and L-arginine incorporation into de novo synthesized proteins was compared in six organisms. Utilizing L-[guanidinooxy¹⁴C]canavanine and L-[guanidino¹⁴C]arginine at substrate saturation, the canavanine to arginine incorporation ratio was determined in de, novo synthesized proteins.Caryedes brasiliensis andSternechus tuberculatus, canavanine utilizing insects;Canavalia ensiformis, a canavanine storing plant; and to a lesser extentHeliothis virescens, a canavanine resistant insect, failed to accumulate significant canavanyl proteins. By contrast,Manduca sexta, a canavanine-sensitive insect, andGlycine max, a canavanine free plant, readily incorporated canavanine into newly synthesized proteins. This study supports the contention that the incorporation of canavanine into proteins in place of arginine contributes significantly to canavanine's antimetabolic properties.     

New contribution to the study of chromosomes of the European Cryptocephalinae (Coleoptera,Chrysomelidae)

Summary The chromosomes of three species ofPachybrachis and nine ofCryptocephalus chrysomelids were analyzed. The male meiotic bivalent formula ofP. azureus Suffr.,P. catalonicus Burl. andP. petitpierrei Daccordi is 7^II+Xy_r.Cryptocephalus sexmaculatus Ol. andC. vittula Suffr. have 13^II+Xy_p,C. bipunctatus L. 14^II+Xy_r,C. ochroleucus Steph. andC. ocellatus Drap. 14^II+Xy_p,C. crassus 01. 15^II+Xy_r,C. sulphureus 01. 15^II+Xy_p, the same number as inC. fulvus Goeze with 2n=32 chromosomes, whileC. primarius Har. has 19^II+Xy_p. The modal chromosome number inCryptocephalus is 2n=30 (about 60% of spp.), and most species are characterized their small chromosomes. The low variation found in the karyotypes of Cryptocephalinae along with their possible interrelationships with allied chrysomelid subfamilies are also discussed.     

The role of glycine in the biosynthesis of a terpene

Zusammenfassung Mit doppelt markiertem Glycin konnte gezeigt werden, dass das Kohlenstoffatom der Methylgruppe viel besser als das Kohlenstoffatom der Karboxylgruppe in die Isoprengruppe des Ophiobolins B ausCochiobolus miyabeanus eingebaut wird. Die Radioaktivität wird in Ophiobolin B eingebaut, wenn die folgenden Verbindungen verwendet werden: [3-¹⁴C]-Serin, [¹⁴C-Methyl]-Sarcosin, [¹⁴C-Methyl]-Methionin, und [¹⁴C] Formate.

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a)Studies on Biosynthesis. Part V. for Part IV, seeM. Anchel, A. K. Bose, K. S. Khanchandani andP. T. Funke, Phytochem.9, 2135 (1970). b) Presented in part at the 3rd Natural Products Symposium, University of West Indies, Jamaica, January 1970.

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The support of this research by Stevens Institute of Technology is gratefully acknowledged. We wish to thank Dr.J. H. Davis and Prof.L. Z. Pollara for their interest and encouragement and Drs.H. Levy, P. T. Funke, M. S. Manhas, P. K. Bhattacharyya andM. Anchel for valuable discussions and help with some of the experiments. We are particularly thankful to Dr.L. Canonica for providing us with cultures ofCochiobolus miyabeanus that made our work on ophiobolin B possible.     

Complexed rheumatoid factor measurements in sera, synovial fluids and in immune complex fractions.

Mild acidic treatment increases the rheumatoid factor titre of some sera and synovial fluids (SF) in rheumatoid arthritis (RA), juvenile RA (JRA) and most frequently in rheumatoid vasculitis. This unmasking of 'hidden' RF in serum and SF samples correlated with the RF-immune complexes (RF-IC) and complexed C4 present in the 3% polyethylene glycol (PEG) precipitates, indicating that by means of 'hidden' RF measurements RF-ICs are possibly detected. This method seems to provide a diagnostic tool for detecting RF-ICs in RA and other related diseases.     

Transient ischemic alteration of synaptosomal neutral acid uptake

Summary The effect of cerebral ischemia and postischemia on the synaptosomal uptake of some neutral amino acids was determined in mongolian gerbils at various periods of time. A transiently increased uptake of³H isoleucine,¹⁴C cycloleucine and³H phenylalanine in the synaptosomes was found after 3 min of bilateral common carotid occlusion which returned to normal at 30 min of reestablished cerebral blood circulation.     

Influence of progesterone on protein and RNA synthesis in cultured chick embryo liver cells

Summary Chick embryo liver primary cultures, when added with progesterone, exhibit, in comparison with the controls, a normal growth, a decline of both³H-uridine uptake and incorporation into total RNA, a decline of³H-leucine and¹⁴C serine incorporation into the proteins. Progesterone is not able to stimulate phosvitin synthesis induction.These studies were supported in part by the Italian CNR grants.     

Chemical defense in the three European species ofCrematogaster ants

The composition of the Dufour gland of the antC. scutellaris has been reinvestigated by gas chromatography/mass spectrometry. The major components of the gland are (2E,5E,12Z)-4-oxoheneicosa-2,5,12-trien-1-ol acetate (1a) its ¹⁴ and ¹⁶ double bond isomers (1b and1c), and the corresponding (Z,Z)-dienes5a and5b, all containing an acetylated C₂₁ chain. The previously proposed structures1d, 1e, and5c, which are based on an homologous acetylated C₂₃ chain, correspond to minor derivatives present in the gland. Traces of acetylated C₁₉ homologs, tentatively identified as1g-1i, have also been found. The Dufour gland contents of the two other EuropeanCrematogaster species have also been studied.C. auberti is very similar toC. scutellaris in producing mainly1a, 1b and1c, together with the same higher and lower homologs, but it lacks the dienic derivatives5, whereasC. sordidula contains essentially the acetylated C₁₉ compounds1g, 1h, and1i, accompanied by acetylated C₁₇ homologs.     

In vitro synthetic activity of the juvenile ovotestis ofHelix aspersa: Influence of the brain and the dorsal bodies

Summary A bioassay was developed inHelix aspersa to study the effect of known endocrine centers on the twomonth-old gonad, using organ culture. The incorporation of¹⁴C leucine and³H fucose in the juvenile gonad almost doubled over control levels, in the presence of the brain and the dorsal bodies.     

Über den Einbau von Dipeptiden in Ergotoxin-Alkaloide

Summary l-Valyl-l-leucine-U-¹⁴C,l-valyl-l-proline-U-¹⁴C-lactam andl-leucyl-l-proline-U-¹⁴C-lactam were administered to submerged cultures of an ergotoxine-mixture-producing strain ofClaviceps purpurea. The added dipeptides were split by the fungus into the corresponding amino acids prior to incorporation. Apparently dipeptides are no immediate precursors for the peptide side-chain of ergotoxinealkaloids.     

The use of fungal protoplasts in the study of aflatoxin biosynthesis

Summary Protoplasts derived fromAspergillus flavus are shown to be capable of synthesizing aflatoxins when incubated in a chemically defined medium.¹⁴C-Acetate and¹⁴C-Versicolorin A, added to protoplasts from 3-day-old mycelium, are incorporated into aflatoxin B₁.     

Ca-antagonistic substance from soft coral of the genusSarcophyton

Summary A 14-membered ring diterpenoid named cembrane, possessing Ca-antagonistic action on the isolated rabbit aorta, has been isolated from a soft coral of the genusSarcophyton, and its structure established by X-ray and spectroscopic data.The authors thank Mr. Z. Nagahama (Okinawa) for collection of soft corals, Miss R. Abe (the present institute) for her skillful assistance, and Dr. T. Higashijima, Prof. T. Miyazawa (Tokyo University), Mr. T. Hayase and Dr. H. Ohtani (Mitsubishi Chemical Industries Ltd) for¹H and¹³C NMR-measurements.     

Effect of propylene glycol and ethanol on3H-noradrenaline efflux from an isolated blood vessel

Summary Propylene glycol (14 mM), but not ethanol (17 mM), enhanced the late phase of passive³H-efflux from rabbit isolated aortic rings preloaded with³H-(–)-noradrenaline. We conclude that, with regard to³H-noradrenaline release studies, propylene glycol is unsuitable for aiding the dissolution of e.g. corticosterone in physiological salt solution, while ethanol can be used for this purpose.This study was supported by the Danish Medical Research Council. The authors gratefully acknowledge the technical assistance of Miss Mariann Wolmar.     

Multiple phosphoglucomutase alleles in two species ofMansonia mosquito

Summary Multiple phosphoglucomutase (E.C.2.7.5.1) alleles are found in the mosquitoesMansonia crassipes andM. uniformis. The present study reveals 4Pgm alleles, of whichPgm ^B andPgm ^C are common to both species whilePgm ^A is present only inM. crassipes andPgm ^D only inM. uniformis. The frequencies in both species accord well with Hardy-Weinberg expectations. The most frequent allele is that controlling a phenotype with an intermediate electrophoretic mobility, viz.Pgm ^B inM. crassipes andPgm ^C inM. uniformis.This work is supported in part by a University of Malaya research grant to the senior author.     

Über den Einbau von Anthranilsäure in Peganin

Summary Anthranilic acid-(¹⁴COOH) was administered to rooted leaves ofAdhatoda vasica Nees. The isolated alkaloid peganine = vasicine was degraded according to the method ofSpäth andHikawitz (Figure). The anthranilic acid obtained showed the same specific radioactivity as the alkaloid. Therefore anthranilic acid must be regarded as a direct precursor of peganine inA. vasica Nees.     

Blood volume and extracellular space (ECS) of the whole body and some organs of the rat

Summary Methods are described for estimation of blood volume and extracellular space (ECS) in the whole body and in some organs with⁵¹Cr,¹⁴C-thiocyanate and³H-inulin. A mean blood volume of 47 ml/kg, a thiocyanate space of 350 ml/kg and a inulin space of 288 ml/kg were determined in the rat. The corresponding values of organs are shown in figures 1–3.     

Comparison of the production rates of bacteria in the rumen estimated by using labelled live and formaldehyde treated mixed bacterial cells

Summary The bacteria production rates in the rumen have been estimated by injecting¹⁴C- and³⁵S-labelled mixed rumen bacteria, either live or killed by treatment with formaldehyde, into the rumen and applying isotope dilution technique. The rate of bacteria production when estimated by using either live- or dead-(protected-)labelled bacterial cells were comparable.