Band 30, Heft 11-12

Electronic Structure, Metmyoglobin, Metmyoglobin Fluoride, Methemoglobin The electronic term scheme of ferric iron in metmyoglobin, metmyoglobin fluoride, and met­ hemoglobin is evaluated by a Hamiltonian which involves the Coulomb repulsion of the 3d electrons, their interaction with the C 2v -coordinated ligands, and spin-orbit coupling. The adjustable parameters of the theory were determined by a least squares fit to experimental EPR, susceptibility, and far-infrared data reported in the literature. According to these results, the structural properties of the ferric ion and its neighboring ligands were discussed by means of group theoretical arguments: An increasing out of plane position of the ferric ion is found in the sequence metHb- metMb -MbF which corresponds to an increasing binding strength with the axial ligands.

1. Under the conditions used in our investigation, tripalmitin layers of the Langmuir Blodgett (LB) type undergo a spontaneous transition, leading from a liquid crystalline (LB) state to a microcrystalline (CR) state. 2. This transition is accompanied by a shift of the methylene bending band from 1469 to 1473 cm -1 and a shift of the ester group motion from about 1169 to 1182 cm -1 . In both cases the half widths of the absorption bands are reduced. 3. The two components of the methylene bending band comprise, within experimental error, all of the tripalmitin present. This is demonstrated by the constancy of the sum of the two band areas attributed to the LB and the CR state respectively. Furthermore, this observation indicates that the liquid crystalline and the crystalline state are the two main types of structural organization occuring in these layers.

Dialysis rates of cholesterol, calcium chloride dihydrate and of their mixture in 90% aqueous dioxane through Visking cellulose membrane were characterized by half-escape times ( t ½) of 2.2, 1.0 and 10.5 hours, respectively. Slow dialysis rate observed with the mixture was due to complex formation between four molecules of cholesterol and two molecules of calcium chloride dihydrate, molecular weight 1800 to 2000. The association constant for this complex in 90% aqueous dioxane was estimated to be 3.9 × 10 14 . Rates of dialysis obtained with a natural protein membrane were in the reverse order to those obtained with cellulose membrane. Half-escape times for cholesterol, calcium chloride dihydrate and for their mixture were 0.6, 6.7 and 1.4 hours, respectively. Determinations of milliosmolality of the three solutions by freezing point depression indicated that in the mixture there were fewer osmotically active same molarity, also suggesting formation of the complex which was detected by dialysis experiments.

A gas chromatographic detector is described which uses an insect antenna as a sensing element and permits the continuous monitoring of pheromones and other compounds with olfactory activity. In high-resolution gas chromatography allowing separations of positional and geometrical isomers, the electroantennographic detector gives precise information on the retention times of active compounds and permits the analysis of insect pheromones with exceedingly small amounts of material.

Using an electron capture detector, a sensitive gas chromatographic method has been developed for the determination of the juvenile hormone methyl(2E, 6E)-10, 11-epoxy-3,7,11-trimethyl-2,6-dodecadienoate (JH III) in insect material. The sensitivity in electron capture detection of the bisheptafluorobutyrate was determined. The work-up procedure was checked by adding known amounts of JH III to insect material. The method seems equally applicable to all three juvenile hormones.

Some receptor proteins were isolated from the ovaries of Tenebrio molitor L. One had a molecular weight of 8 × 10 5 and an isoelectric point of 5.4. In the range of 1 × 10 6 - 4 × 10 7 dalton JH-binding particles are existing with the same isoelectric point of 2.5. All proteins showed allosteric effects. Under the used conditions they are stable against heating and some enzymes, precipitable with 5% trichloro acetic acid and hydrolyzable with 1 ɴ HCl. The binding is specific and not displaceable with a great excess of substances with the same polarity.

A new NAD ⊕ -isomer was prepared, in which the ᴅ-ribose of the adenosine moiety was sub­ stituted by the enantiomeric ʟ-ribose. As compared to nicotinamide-adenine-dinucleotide (NAD ⊕ ) and NADH the coenzyme isomer (ᴅ,ʟ)-NAD ⊕ and its dihydroform (ᴅ,ʟ)-NADH are far less tightly bound to lactate dehydrogenase and alcohol dehydrogenase from horse liver. In the presence of the second substrate (ᴅ,ʟ)-NAD ⊕ and (ᴅ,ʟ)-NADH act as hydrogen acceptor and hydrogen donator, respectively, with lactate dehydrogenase and alcohol dehydrogenases from horse liver and yeast. Compared to NAD ⊕ and NADH the Michaelis constants are always increased, the catalytic constants (V/E t ) were found to be decreased except for the dihydroform reacting with alcohol dehydrogenase from liver.

Streptococcal Proteinase, Active Center Peptide, Peptide Synthesis The synthesis and properties of the protected peptide Boc-His(Boc)-Cys(X)-Val-OH(ONP) [X = ferf-butylmercapto, p-methoxybenzyl, tetrahydropyranyl-(2) ] are described. This peptide is a fragment of an active center sequence of the streptococcal proteinase (EC 3.4.22.-10) containing the essential SH group of the enzyme.

The synthesis of the protected peptides Boc-Ala-Ala-Thr-Gly-ONp, Boc-Ala-Thr-Ala-Thr-Ala-ONB and Boc-Ala-Ala-Thr-Gly-His-Cys(X)-Val-Ala-Thr-Ala-Thr-Ala-ONB [X = p-methoxybenzyl, tertbutylmercapto, tetrahydropyranyl-(2)] is described. These peptides are fragments of an active center sequence of the streptococcal proteinase (EC 3.4.22.10) which contains the essential SH group of the enzyme.

The synthesis of the protected tricosapeptide Z-Val-Lys (Z)-Pro-Gly-Glu (OBzl)-Gln-Ser-Phe-Val- Gly-Gln-Ala-Ala-Thr-Gly-His-Cys(MBzl)-Val-Ala-Thr-Ala-Thr-Ala-ONB is described. The tricosapeptide was built up from the decapeptide Z-Val-Lys (Z)-Pro-Gly-Glu (OBzl)-Gln-Ser-Phe-Val-Gly- ONp and the tridecapeptideester Gin-Ala-Ala-Thr-Gly-His-Cys (MBzl)-Val-Ala-Thr-Ala-Thr-Ala-ONB. A further nonadecapeptide with tert-butylmercapto protection of the SH group was also synthetized.

Glucose-6-phosphate Dehydrogenase, Reduction Charge, Pentosephosphate Cycle, Chloroplasts Glucose-6-phosphate dehydrogenase from intact pea chloroplasts is partially membrane bound and inactivated upon illumination. The inhibitory effect of light can be abolished by addition of methylviologen. Kinetic experiments with glucose-6-phosphate dehydrogenase reveal that, in the dark, the enzyme activity is strongly inhibited by the accumulation of NADPH. The inhibition of NADPH can be reversed by the addition of excess NADP + . The non-Michaelis-Menten-type kinetics suggest that the enzyme is stringently regulated by the ratio of NADPH to NADP + plus NADPH, i. e., the “reduction charge”. These observations seem to indicate that in the light the inhibition of glucose-6-phosphate dehydrogenase is due to a high reduction charge, whereas in the dark the enzyme is controlled by the metabolic demand for reducing equivalents.

The effects of divalent salts and 3-(3,4-dichlorophenyl) -1,1-dimethylurea (DCMU) upon nicotinamide adenine dinucleotide phosphate (NADP) reduction and P 700 in isolated chloroplasts are described and compared with the influence of DCMU on oxygen evolution and P 700 in intact cells. Most experiments were carried out with a steady-state relaxation spectrometer. A kinetic mechanism for the estimation of P 700 fluxes is proposed and experimentally tested. Good agreement between theory and experiment was found. Concurrent measurements of P 700 and NADP reduction revealed two antagonisms: addition of divalent cations caused an increase in the yield of NADP reduction and a decrease in the yield of P 700 . Conversely, in the presence of Mg 2+ low concentrations of DCMU decreased the yield of NADP reduction and increased the yield of P 700 . Aging of the chloroplasts at 30 °C exerted a similar effect. With far-red actinic light, Mg 2+ stimulated the yield of NADP reduction without affecting the flux. Also, in the absence of Mg 2+ , DCMU inhibited both reactions although P 700 required a higher herbicide concentration for fractional inhibition than NADP reduction. In the presence of Mg 2+ , chloroplasts resembled intact algae in which a high rate of oxygen evolution was accompanied by little P 700 turn-over. Titration with DCMU decreased the rate of photosynthesis and increased P 700 flux. On the whole, the data suggest that P 700 relaxing in 20 msec is not directly involved in linear electron transport.

Rhodopseudomonas palustris (ATCC 17001) develops energy-dependent NADP + transhydrogenase activity while growing photosynthetically on thiosulfate, formate, or acetate as the electron donors. The enzymatic activity is present in the supernatant fraction S-.144 000. - As reported, this fraction contains small membrane fragments but no closed vesicles and was shown to drive energy-dependent reversed electron flow as well as an aerobic respiratory electron transport. The energy-dependent transhydrogenase reaction in this fraction can be driven either by ATP, ADP, or inorganic pyrophosphate, but also by acetyl phosphate or acetyl-coenzyme A in the presence of orthophosphate. - Arsenate acts as an inhibitor and decreases preferentially the acetyl-coenzyme A-dependent and the acetyl phosphate-driven reaction; whereas, oligomycin inhibits preferentially the ATP-and the acetyl phosphate-dependent reactions. - Acetate kinase and a phosphotrans-acetylase are operative in S-144 000.

The amplitude of the fast uptake and the initial rate of the slow uptake increase with in­ creasing free calcium concentrations, up to 30 μᴍ. In that range, both processes are correlated to each other. At higher concentrations, the slow uptake is more inhibited than the fast uptake. The fast uptake shows a maximum amplitude which remains unchanged in the presence of phosphate. The slow uptake leads to a nearly complete depletion of the external calcium, and its rate is proportional to the phosphate concentration, even at physiological range. The sarcoplasmic ATPase liberates inorganic phosphate and the slow uptake

Deoxyribonucleases, Disc Electrophoresis, Lymphocytes Four groups of deoxyribonuclease activities from human lymphocytes have been characterized by deoxyribonuclease assay in DNA-containing polyacrylamide gels following their separation by disc-electrophoresis. All activities hydrolyse DNA endonucleolytically. One neutral deoxyribo­ nuclease found in the cytoplasmic fraction prefers native or UV-irradiated DNA over denatured DNA as substrate and is a 5′-monoester former. Two groups of acid deoxyribonuclease activities are detectable in the nuclear fraction. Both are 3′-monoester formers. One is as well active with denatured DNA as with native DNA, the other one shows the same activity with native and UV-irradiated DNA but lower activity with denatured DNA. An alkaline deoxyribonuclease activity, also localized in the nucleus, is a 5′ -monoester DNA as substrate.

The effects of lysolecithin and of 2 synthetic ether-desoxy lysolecithin analogs, containing alkyl residues of 16 or 12 carbon atoms, on the agglutination kinetics of calf and rabbit thymocytes by concanavalin A (Con A) were investigated. Unlike the natural lysolecithin, these synthetic analogs are resistant to metabolism by membrane associated enzymes. It was found that pretreatment of thymocytes with lysolecithin or with the C 16 -analog leads to slightly increased agglutination rates. The C 12 -analog, in contrast, significantly inhibits thymocyte agglutination by Con A. More­ over, a comparison of these results with lysophosphatide effects on the agglutinability of erythrocytes of various species revealed that the inhibitory effect of the short-chain phosphatide is rather specific for thymocytes. The finding that long-and short-chain lysophosphatides, which have previously been shown to react as adjuvants or immunosuppressants, respectively, induce adserve alterations in thymocyte membranes indicates that these substances may affect the immune response by changing the membrane properties of immune competent cells. Concerning the nature of these membrane alterations it was shown that lysolecithin did not affect the number of Con A receptors per cell nor the affinity of lectin binding. It is therefore concluded that the lysophosphatide in­ duced alterations of Con A agglutinability can not be caused by an uncovering or covering of lectin-receptors.

Confirming our previous ultrastructural and biochemical studies, the combined electron microscopy and immunofluorescence investigations show that phalloidin causes a characteristically striking increase of actin filaments within rat hepatocytes. Filaments are localized mainly at the level of special junctional complexes between contiguous cells and around bile canaliculi.

Vision, Monolayers, Rhodopsin, Photobiology Monolayers of fragments of our rod segments were formed at an air-water interface. The area of these particles was measured as a function of the pH of the aqueous phase. A maximum area was measured at pH 6.5. The film was characterised by measuring the decrease in surface pressure, after compression, and the half time required to reach constant pressure. At a pH between 6 and 7 the decrease in surface pressure was a minimum. Irradiation of films of fragments resulted in a decrease in surface potential of between 30 and 40 mV. The largest decrease occured at a pH between 6 and 6.5. A small decrease in surface pressure was also observed upon irradiation. Mixed films of fragments and phosphatidyl ethanolamine were examined. Irradiation of the mixed film resulted in a 70 mV decrease in surface potential.

In a thermosensitive dnaZ mutant lysogenic for λ, induction of the prophage development was provoked at the restrictive temperature. In dnaD strain, spontaneous release of λ proceeded even at 43 °C, but distinct induction of the prophage development was not caused by a heat treatment. Similarly, shift up of growth temperature did not lead to induction of λ in lysogens carrying thermosensitive mutation in dnaH function or DNA polymerase I. In dnaH mutant, multiplication of λ-virulent phage proceeded normally at 43 °C.

The method for assaying thymine-containing dimers in yeast is based on highly efficient ([ 3 H]-deoxythymidine-5′-monophosphate) DNA-specific labelling and employs ascending thin layer chromatography. It allows satisfactory quantitative analysis down to UV-doses of 500 erg/mm 2 .

In haploid and diploid S. cerevisiae the dimer yield ratio TT̂/CT̂ is found to be 1.2/1 and 1.3/1, resp., at the UV (254 nm) unit dose 1 erg/mm 2 , the share of TT̂ and CT̂ in a UV (254 nm) lethal hit being 0.7 TT̂ and 0.6 CT̂. A general formulation of the UV lethal hit is given and discussed. The TT̂ + CT̂ yields obtained for S. cerevisiae are compared to those reported for other organisms. It is found that there obviously exists a directly proportional linear correlation between genome size and TT̂ + CT̂ yield for the UV dose range well below the stationary levels of the TT̂ and CT̂ formation kinetics.

A comparative light and electronmicroscopical study about the structure of the cortex, and the location and nature of the silverlines of Telotrochidium elongatum was performed. There is a fibril in the epiplasm below each pellicular ridge. Ultrathin sections of silver stained specimens demonstrate that silver is deposited at and in these fibrills, not only in animals stained with the wet silver method but also in animals stained with the dry one. These findings confirm Klein’s and our own view about the fibrillar nature of the silverline system. The significance of our findings for the elucidation of the structure and function of the cortex is discussed.

A mixture of 2,5,7,3′,4′-pentahydroxy-flavanone-5-glucoside and its tautomers has been isolated from the seed of Galega officinalis L.; its constitution is prooved by conversion to luteoline-5-glucoside.

The dried bark of Aralia elata Seemann was extracted with n-hexane. Methyl pentadecanoate, methyl hexadecanoate, methyl octadecanoate, methyl eicosanoate, methyl docosanoate, methyl tetracosanoate, methyl hexacosanoate, and 1-hexacosene were identified from the extract by means of GC-Mass spectrometer.

From γ-irradiated oxygenated aqueous solutions of DNA, 2-deoxy-tetrodialdose (1) and 2-deoxy-pentos-4-ulose (2) have been isolated as free sugars. The formation of 1 indicates that in the presence of oxygen the DNA strand is not only broken by mere phosphate ester cleavage but also by C -C-bond rupture in the sugar moiety. Such a process has not been encountered in deoxygenated solutions so far. The mechanism for the formation of 1 is discussed.

Inactivation studies with 17 group-specific inhibitors showed that amino, hystidyl and tyrosyl residues probably are components of the active and/or regulatory sites of pig kidney alkaline phosphatase.

Phospholipids, ATPase, E. coli, Mutants The ATPase activities and the amounts of individual phospholipids in E. coli wild types B 163 and ML-308-225 as well as in the mutants AN 120, DL 54 and etc-15 have been examined. The ATPase activities and the amount of cardiolipin are higher in the stationary phase than in the log phase, whereas the amounts of phosphatidylglycerol and phosphatidylserine are lower in the stationary phase. The decreased ATPase activity of the mutants is not due to an altered phospholipid composition.

Details are given of the ultraviolet, optical rotatory dispersion and fluorescence spectra of oxoformycin. The pK of formation of the monoanion is 8.6, at 25 °C. As formycin B has the same pK value, the ionization of both compounds is ascribed to dissociation of a proton from N-1. Both the neutral and monoanionic forms of oxoformycin are strongly fluorescent.

The concentrations of 11 amino acids were determined in 9 regions of the rat brain following the acute administration of the antidepressant drugs imipramine and Org. GB94, and chlorpromazine. The amino acids were determined as their dansyl derivatives. Unequivocal changes were only found in the concentrations of γ-aminobutyric acid, alanine, asparagine + glutamine, glycine and taurine in some brain regions. Chlorpromazine produced the greatest change in these amino acids. Imipramine and Org. GB94 had qualitatively different effects on the concentrations of the amino acids in the 9 brain regions.

It is shown that out-of-plane fluctuations of two-dimensonally fluid membranes may lead to a decrease in effective area and affect stretching elasticity.

It is proposed that the biological communication is a language process with the basic word structure formed as a hexagonal neighborhood on the α-helix region of protein molecules.

An in vitro transformation of bone marrow cells has been demonstrated for two strains of avian erythroblastosis virus (AEV-R and AEV-ES4). The transformed cells were indistinguishable from in vivo transformed erythroblasts in morphology and staining characteristics and could be propagated to large numbers. The transformation efficiency could be greatly increased by the addition of dimethyl-sulfoxide (DMSO). The number of foci appearing in the presence of DMSO was proportional to the virus concentration.

Cell titer in peripheral hemolymph of crayfishes rises in less than one hour after administration of stress. The stress may be wounding or handling of the animals.

Bee, Vision, First Optic Ganglion The lamina ganglionaris of the bee contains the first synaptic region in the optic tract. The nine retinula cells of one visual unit (ommatidium) either end in the lamina as short visual fibres or end as long visual fibres in the second optic ganglion (medulla). Each axon bundle of nine fibres from one ommatidium is associated with four different second order neurons (L-fibres) to form a single lamina cartridge. Processes of additional fibres invade single groups of cartridges.

By injecting [1 - 14 C] acetate into the flowers of Matricaria chamomilla L. up to two percent were incorporated in the essential oil. The highest labelling was analysed in the en-in-dicycloether, a hydrocarbon and in an unknown polar compound after 12 days incorporation time. The hydrocarbon and the polar compound may be precursors for the other compounds in the essential oil.

Caffeine, Circadian Rhythm, Sleep and Wakefulness, Phaseolus coccineus L. 4-hour caffeine pulses (10 mᴍ) offered via the trans­ piration stream advances or delays the phase of the circadian leaf movement rhythm of Phaseolus coccineus as a function of the phase of application. It is hypothesized that the caffeine effect upon sleep and wakefulness in man is partly due to this phase-shifting effect.