Band 31, Heft 9-10

8 classes of homo- and heterolateral wide field neurons of the Lobula plate of Calliphora erythrocephala were investigated electrophysiologically and identified by intracellular injection of procion yellow. All recorded neurons were motion-sensitive. Some of the homolateral neurons respond only with graded potentials to visual stimulation; all heterolateral elements generate spike potentials. Connections between identified neurons were investigated by means of simultaneous double recordings. The described neurons are compared with units known from earlier extracellular studies.

A tobacco-like odorous compound isolated from a bloom of the blue-green alga Microcystis wesenbergii and a laboratory culture of M . aeruginosa was analysed by gas-liquid chromatography and mass spectrometry. Its structure was determined as β-cyclocitral. No other monoterpenes have been detected in these and in other blue-green algae. The hydrocarbon content was 0.10 - 0.18% of the dry weight. n-Hexadecane, n-heptadecane, 4-methylheptadecane and n-octadecane constituted the main components. The relation of the different alkanes to each other, especially 4-methylheptadecane and n-octadecane, revealed marked differences in the two organisms.

The secretion of the nasal gland from the marsh deer (Odocoileus dichotomus) has shown to be a lipid mixture predominantly containing cholesterol esters, mono-and diester waxes, the latter of which containing 2-hydroxy fatty acids. The alcoholic constituents of the mono-and diester waxes contain considerable amounts of mono-unsaturated homologues, all with double bonds in(ω-9) position.

The electroantennogram-active compound in abdominal tip extracts of E. ambiguella females was identified as cis-9-dodecenyl actetate. The compound was present at a level of 25 ng per female and absent in a male extract. The synthetic chemical shows prominent electroantennogram activity, elicits a mating dance response in the males, and is attractive in the field. The results indicate that cis-9-dodecenyl acetate is a major component of the E. ambiguella sex pheromone.

Four antifungal isoflavones [7-hydroxy-4′-methoxy-(l) ; 5,7,4′-trihydroxy-(2) ; 5,7,2′,4′-tetra-hydroxy-(3) ; 5,2′,4′-trihydroxy-7-methoxy-(4) ] and one isoflavanone [ (5,2′-dihydroxy-7,4′-dimeth-oxy-(7)] have been isolated from the fungus-infected stems of Cajanus cajan . A sixth compound has been provisionally identified as 5,2′-dihydroxy-7,4′-dimethoxyisoflavone (5). The structure of 5,2′-dihydroxy-7,4′-dimethoxyisoflavanone (cajanol) was confirmed by synthesis from ferreirin ( 5,7,2′-trihydroxy 4′-methoxyisoflavanone).

In the yeasts C. albicans, C. tropicalis, and C. stellatoidea but not in C. krusei, R. rubra, and S. cerevisiae enzyme activity was found by which - as by the catechol-O-methyltransferase (EC 2.1.1.6) found in the liver - the O-methylation of epinephrine to metanephrine and paranephrine, of 3,4-dihydroxybenzoic acid to 4-hydroxy-3-methoxybenzoic acid and 3-hydroxy-4-methoxybenzoic acid, and of 6,7-dihydroxycoumarin to 7-hydroxy-6-methoxycoumarin and 6-hydroxy-7-methoxy-coumarin is catalysed. When the substrates 3,4-dihydroxybenzoic acid, or 6,7-dihydroxycoumarin or epinephrine were incubated in the presence of S-adenosyl-ʟ-[methyl- 14 C] methionine and S-adenosylmethionine hydrogensulfate with a 100 000 X g supernatant of C. albicans, C. tropicalis or C. stellatoidea the cor­responding O-methylethers were detected in the extracts of the incubation medium by thin-layer chromatography. Final identification of the isomeric radioactive O-methylethers obtained from 3,4-dihydroxy­ benzoic acid and 6,7-dihydroxycoumarin was performed after thin-layer chromatographic separation by the reversed isotope dilution technique. The radioactive m-and p-O-methyl derivatives from epinephrine were separated by thin-layer chromatography and then cleaved with periodate to the corresponding aldehydes which were also identified mainly by the reversed isotope dilution technique.

Ultraviolet irradiation of 5-ethylorotate in aqueous medium led to formation of 5-ethylidene-hydroorotate via a 1,3-hydrogen rearrangement from the ethylene group of the 5-substituent to the ring C 6 . The same product was also obtained by an alternate pathway via a hitherto un­identified intermediate. The structure of this unusual pyrimidine analogue, established in the solid state by X-ray diffraction, was shown with the aid of spectroscopic methods to be the same in solution, and some of its properties are described. Heating of 5-ethylidenehydroorotate in the solid state led by direct conversion to a mixture of the parent 5-ethylorotate and 5-ethyluracil. By contrast, ultraviolet irradiation in aqueous medium resulted in quantitative photochemical conversion of the photoproduct to 5-ethyluracil.

X-ray diffraction methods have been employed to establish the crystal structure of a new, unusual pyrimidine analogue, 5-ethylidenehydroorotate, obtained by a photochemical rearrangement of 5-ethylorotate. Crystals of the calcium salt of the title compound are monoclinic, space group Pc, cell constants a=14.631, 6 = 10.038, c = 19.168 Å,β = 137.7°, and contain four molecules, two cations and three water molecules per asymmetric unit. The structure was solved by direct methods and refined to R = 5.2% on the basis of 2653 diffractometer measured data. The four independent molecules represent two pairs of enantiomers with slightly differing conformations linked together by an intricate system of hydrogen bonding and Ca2+-coordination (pentagonal bipyrimidal). The structure of the compound in aqueous medium, as that in the crystal.

A monomeric allosteric haemoglobin from Chironomus thummi thummi was reconstituted with 57 Fe-haem. This reconstituted haemoglobin was found to be identical to the non-reconstituted material with regard to the O 2 -binding properties and the visible spectra. The 270 MHz proton magnetic resonance of the bis(cyano)- 57 Fe-haemin shows that the reconstituted haem is identical with the non-reconstituted haem. Furthermore it has been proved by proton magnetic resonance that in Chironomus haemoglobins the prosthetic group is proto-haem IX. The ESR spectrum of the native nitrosyl haemoglobin demonstrates rhombic symmetry of the haem iron (g xx = 2.086, g yy =1.981, g zz =2.005) and hyperfine structures at g yy (aN ε = 1.35 mT) and at gzz (a 15 NO = 3.05 mT, a 14 NO = 2.19 mT, aN ε =0.715mT, a 57 Fe = 0.38 mT). The spectrum is independent of pH and can be classified as a type II spectrum following the classification of ref. 2. NO-binding obviously stabilizes the tertiary structure of this haemoglobin in a “tense” conformation with a relatively strong o bond of the 5th ligand (N ε of imidazole) and a relatively weak o bond of the 6th ligand (NO). Reaction of this haemoglobin with anionic, cationic and non-ionic detergents, respectively, leads to a transformation of the NO-ligated form into a “relaxed” conformation with a stretched or broken a bond of the 5th ligand (N ε of imidazole) and a strong σ bond of the 6th ligand (NO). The ESR spectrum of this modified NO-haemoglobin shows again a rhombic symmetry of the haem iron (gxx = 2.10, gyy = 2.06, gzz=2.010), but dramatically changes in the g tensors (low field shift), hyperfine structures and hyperfine splitting constants (a 15 NO=2.32 mT, a 14 NO = 1.66 mT, a 57 Fe = 0.48 mT). The hyperfine splitting is isotropic. Transition from the “tense” conformation to the “relaxed” conformation corresponds with an increase of the spin density at the iron atom by 26% and a decrease of the spin density at the NO ligand by 25%. The spin density at the N ε of imidazole strongly decreases in the “relaxed” conformation, so that a hyperfine splitting of this ligand is not any more resolved. These results demonstrate the trans-effect of the proximal imidazole which in haemoglobins controls the binding properties of the external ligand in trans-position.

The synthesis by conventional methods of the peptides Z-Asp-Cys-NH 2 , Z-Asp-Gly-Cys-NH 2 , Z-Glu-Gly-Cys-NH 2 , Z-His-Ala-Gly-Gly-Cys-NH 2 , Z-His-Ala-Asp-Gly-Cys-NH 2 and Z-His-Ala-Asp- Gly-OCH 3 is described. Cystin was used for SH-protection; reduction of the disulfides was performed by mercaptoethanol. The hydrolytic activity of these peptides with p-nitrophenylacetate as substrate was compared with the activity of a number of peptides described in the literature.

The Conservation of the phosphoanhydride-energy of inorganic pyrophosphate (PP) in micro­bial metabolism requires a stringent metabolic control of the intracellular pyrophosphatases (PPases, EC 3.6.1.1). In this article, the rate of intracellular PP-liberation during biosynthesis of cellular constituents is calculated from the specific growth rate and the macromolecular composition of the respective microorganism. This rate is compared with the maximal specific activity of PPase in cell free extracts or purified enzyme preparations in order to investigate the possibility of the limitation of biosynthesis through PPase-activity. The catalytic and regulatory properties of microbial PPases are discussed in respect to the occurrence of PP-dependent transphosphorylases. The evidence showing that certain anaerobic microorganisms including photosynthetic bacteria, can use PP instead of ATP as phosphate donor for transphosphorylation reactions will be discussed.

A method is described for the rapid purification of radioactively labeled deoxyribonucleoside tri­phosphates from their spontaneously emerging hydrolysis products deoxyribonucleoside diphosphate, deoxyribonucleoside monophosphate, and deoxyribonucleoside. The separations which are finished within 3 min or less are carried out on a 0.1X5 cm column filled with LiChrosorb-NH 2 , using isocratic elution with 0.025 м potassium phosphate, pH 6 .8 , in a high-pressure liquid chromatograph at room temperature and a flow rate of 30 ml · h -1 (flow velocity 63.7 cm·min -1 ).

The (adenine + thymine)/(guanine + cytosine) base ratios of 19 species of adriatic sponges have been determined by high-pressure liquid cation-exchange chromatography. The base ratios vary from 1.49 (Mycale massa) to 0.63 (Hippospongia communis) according to an (A+T) content of 59.7 and 38.6 mol%, respectively. The DNAs of sponges of the order Keratosa showed marked differences in their (A +T) contents (39.5 to 58.8 mol%) whereas those of Tetractinellida and Halichondrina were nearly identical (39.3 to 40.8 and 49.5 to 49.8 mol%, respectively). The 5-methylcytosine (5MC) content was determined in 8 sponge DNAs by a semiquantitative method. The values differed from 0.8 to 2.2 mol% of 5MC.

Isolated T 4 phage DNA (ϱ = 1.694 g/ml) is applied to seedlings of the crucifer Maltliiola incana (DNA density ϱ = 1.698 g/ml). The phage DNA can partly be reextracted from the plants in a specific DNA fraction, which is predominantly characterized by its unusual high density (high density complex = HDC; ϱ = 1.724 g/ml). DNA: DNA hybridization studies show that phage specific DNA sequences are preserved in the HDC. Results of BrdUrd labeling of the plant DNA before and during incubation with T 4 DNA suggest that the HDC is composed of T 4 DNA and a plant DNA component of high density. The analysis of ultrasonicated HDC confirms this suggestion. The ability of plant cells to recognize and handle T 4 DNA specifically is discussed.

Data regarding the role of oxygen in nitrite reduction are presented. In an NADPH-generating system including homogeneously purified ferredoxin-NADP reductase, ferredoxin (or flavodoxin) and nitrite reductase from the alga Bumilleriopsis filiformis, oxygen and nitrite can be reduced simultaneously. In air, rates of 1.2 μmol nitrite reduced· min -1 · mg -1 nitrite reductase are ob­tained, which are physiologically feasible. Ferredoxin is inhibited non-competitively by oxygen during nitrite reduction. Oxygen uptake due to the oxidase reaction of ferredoxin-NADP reductase mediated by flavodoxin from Chlorella fusca and ferredoxin from Bumilleriopsis involves superoxide and is inhibited by the nitrite reducing system.

Surface properties of monomolecular films of chlorophyll (Chi), plastocyanin (Pc), cytochrome c (Cyt) and ferridoxin (Fd) were measured at a heptane-water interface. Mixed films of Chl and the other components were examined in darkness and in light. The area/molecule, A, for Fd (from Cl. pasteurianum) is much larger at a heptane-water than Fd (from spinach) at an air-water interface. This difference in A may be the source of the Fd or the extent of denaturation at the different interfaces. There appears to be a photoreaction between Chil and Fd in the presence of ascorbate. The A for Cyt is much larger at a heptane-water than at an air-water interface. In mixed films there is a strong interaction between Chl and reduced Cyt in the dark. No such interaction is ob­served between Chi and oxidized Cyt. With mixed films of Chi and reduced Pc there is a significant, reversible, light induced change in ΔV.

Three fluorescent dyes (a merocyanin, a cyanin and a modified umbelliferon) have been in­corporated into vesicles from three different lecithins. Their absorption spectrum, emission spectrum and fluorescence polarization in the lipid vesicles has been studied and compared with the spectral properties in homogeneous organic solutions. The reactivity of lipid bound dyes with reagents in the aqueous phase was investigated. The location use as indicators of phase transitions or membrane

Trigalactosyl diglyceride was isolated from leaves of Urtica dioica and characterized by thin layer chromatography, infrared spectroscopy and by its fatty acid composition. An antiserum to the trigalactolipid was obtained by immunization of rabbits. By means of inhibition experiments with oligosaccharides and mono-and digalactosyl glycerol it was demonstrated that the antibodies are directed towards the α-galactosyl-(1 → 6) -α-galactosyl-(1 → 6) -β-galactosyl-(1 → 1) -glycerol con­figuration of the trigalactosyl diglyceride. Monogalactosyl diglyceride and sulfoquinovosyl diglyce­ ride do not react with this antiserum. However, a cross reaction was observed with digalactosyl diglyceride. The presence of antibodies to tri-and digalactosyl diglyceride was demonstrated in antisera to different chloroplast preparations of Antirrhinum majus and Spinacia oleracea. The antiserum to the trigalactolipid agglutinates stroma-freed chloroplasts. Membrane fragments obtained by the ultra sonication were precipitated. The antiserum is exhausted by trigalactosyl di­glyceride but not by digalactosyl diglyceride or digalactosyl glycerol. The antiserum treated with digalactosyl glycerol and digalactosyl diglyceride also agglutinated stroma-freed chloroplasts. 1 g stroma-freed chloroplasts binds 0.17 g antibodies to trigalactolipid. Membrane fragments bind more antibodies to trigalactolipids than stroma-freed chloroplasts. From the agglutination tests it follows that the antigenic determinants of the trigalactolipid and the digalactolipid are localized in the outer surface as well as in the surface directed towards the inside of the thylakoid membrane.

As was described previously, an antiserum to polypeptide 11000 inhibited photosynthetic elec­tron transport on the oxygen evolving side of photosystem II. The effect of the antiserum on chloro­plasts from two tobacco mutants also clearly showed that the inhibition site is on the photosystem II-side of the electron transport chain. One of the two tobacco mutants lades the oxygen evolving capacity but exhibits some electron transport with tetramethyl benzidine, an artificial donor to PS II. In this mutant electron transport was barely inhibited. The effect of the antiserum on the primary photoevents showed that the initial amplitude of the absorption change of chlorophyll an at 690 nm and that of the primary electron acceptor X 320 at 334 nm both diminished in the presence of the antiserum. Both signals were restored upon addition of diphenylcarbazide another artificial donor to photosystem II. Comparison of the degree of inhibition on the amplitudes of the fast and slow components of the 690 nm absorption change with the manometrically measured inhibition of electron transport shows that besides a full inactivation of a part of the reaction centers of photosystem II another part apparently mediates a fast cyclic electron flow around photosystem II as reported by Renger and Wolff earlier for tris-treated chloroplasts. Moreover, the antiserum affects the low temperature fluorescence in a way which is opposite to Murata’s effect of the Mg 2+ -ion induced inhibition of energy spill-over from photosystem II to photosystem I. The antiserum under the condition in which the Hill reaction is inhibited lowered the 686 nm emission and enhanced the 732 nm emission which indicates an enhanced energy spill-over to photosystem I.

After careful lysis the nucleoid of Pseudomonas testosteroni can be isolated in three different forms with compact and unfolded DNA structures 1 . The released nucleoids contain endogenous DNA-dependent RNA-polymerase activity using the chromosomal DNA as a template. RNA syn­ thesis is proportional to duration of RNA-polymerase reaction and amount of DNA-protein-complexes. The sensitivity towards ionic strength and rifampicin indicates that a part of RNA-polymerase activity is tightly bound to the chromosomal DNA.

Cytochrome b 6 -f particles were prepared from chloroplasts of spinach and the heterokont alga Bumilleriopsis filiformis using digitonin in comparison with non-ionic detergents. The cytochrome b 6 -f particles are solubilized in different amounts according to chemical structure and HLB value of the detergent (see Griffin, J. Soc. Cosmet. Chem. 1, 311 [1949]). Also the ratio of the two cytochromes in the isolated particle depends on the detergent used. In case of spinach, it varies from Cyt b 6 : f = 1.5:1 to 4.9:1. These investigations do not strengthen the idea that a cytochrome b 6 -f complex with a stoichiometric composition is present in the photosynthetic membrane. Applica­tion of different detergents is a means for selective solubilization of thylakoid membrane com­ponents.

Mitochondria were isolated using sorbitol and high buffer concentration in the medium. X-ray diffraction patterns arising from the mitochondrial cristae-membrane were recorded in the fully dried state and in two different states in humidity. The Q-function evaluation of these X-ray dif­fraction diagrams resulted in electron density cross-section profiles, which consist of two main peaks of opposite sign and one, respectively two, smaller peaks. The total thickness of the membrane amounts to 120 Å in the dry and 140 Å to 160 Å in the wet state.An interpretation of the cross-section profile is tentatively proposed.

Along with kaempferole-3-sophoroside-7-glucoside and some minor flavonoids the hitherto unknown kaempferole-3- (O-sinapoylsophoroside)-7-glucoside has been isolated from the seed of Brassica napus L. c. v. Petranova; its structure is prooved.

The chirality of the hydrogen transfer to NAD catalyzed by myo-inositol dehydrogenase (myo-inositol: NAD 2-oxydoreductase, EC 1.1.1.18) from Klebsiella pneumoniae (formerly classified taxonomically as Aerobacter aerogenes or Kleb siella aerogenes) was investigated. | 4- 3 H | NAD was enzymatically reduced to | 4- 3 H | NADH with non-labeled myoinositol and myo-inositol dehydrogenase. The stereochemistry of the prochiral center at C4 of the NADH produced was determined. It was found that the label was exclusively located at the (4S) position of the produced NADH. Since the hydrogen transferred from non-labeled myo inositol to | 4- 3 H | NAD must have entered the opposite or (R) position, myo-inositol dehydrogenase from K. pneumoniae should be classified as an (R) or A-type enzyme with respect to the stereochemistry of the hydrogen transfer to NAD.

By means of the in situ assay of deoxyribonucleases in DNA-containing polyacrylamide gels after separation by micro-disc-electrophoresis different deoxyribonucleases are detectable in bull seminal plasma. There are two groups of acid deoxyribonuclease-activities with a pH optimum at pH 5.0, one with a pH optimum at pH 7.4 and an additional one with a pH optimum at pH 8.5.

The cortex radiatus externus and the follicle epithelium of the freshwater teleost Gobio gobio are firmly attached together by a special attaching-mechanism. The apical surface of the plugs of the cortex radiatus externus has recesses and excavations which fit in the short projections of the follicle cells and prevent moving of these cells on the egg mem­branes. This attaching-mechanism also assists in fastening the oocytes (eggs) on the substrate.