Volume 30, Issue 5-6

Computer Analysis, Electrophoresis, Ultracentrifugation A Gaussian-like distribution function with three additional parameters is introduced which describes well the electrophoresis patterns of albumin, prealbumin and transferrin. Electrophoresis and ultracentrifugation patterns with 10-15 overlapping peaks are analyzed by means of the FORTRAN-program DIANA. One obtains the (relative) areas, positions and widths of the peaks. The analysis of a series of patterns proceeds in an automated way after the number of molecular components as well as starting values of the positions and the widths have been chosen in a test period.

The area/molecule (A) and surface potential (∆V) of reduced plastocyanin (pcyan) was measured as a function of pH. At pH 7.5 a maximum is observed for A while a minimum is ob­ served for ∆V. At a surface pressure of 5 dyn/cm the maximum A 5 = 378 Å 2 and minimum ∆V 5 = 335 mV. There is an interaction between pcyan and chlorophyll (Chi) in mixed films. As shown by a decrease of A and V compared to theoretically calculated volues. The largest decrease occurs at a mol ratio of about 2 pcyan: 1 Chl. When mixed films are irradiated in air no changes in surface properties are observed. Irradiation of mixed films of reduced pcyan and Chi in nitrogen results in a decrease in A and an increase of ∆V. The maximum decrease occurs at a mol ratio of pcyan/Chl between 1.5 and 2.0. The direction of change of A is consistant with a conversion of reduced pcyan to oxidized pcyan.

There is a very close steric relationship between the codon-anticodon site which accounts for the genetic code dictionary and a polynucleotide replicase site. Protein biosynthesis must therefore have arisen out of a primaeval polynucleotide replicase system.

Spectrophotometric investigation of the kinetics of the spontaneous reduction of the central metal ion in K 2 [Mn (IV)-2-α-hydroxyethyl-isochlorine e 4 ] acetate in aqueous alkaline solution in the absence of any reducing agent reveals that it is a pseudo-first order reaction which is specifically hydroxide ion catalyzed. The pKα-value of the acid-base equilibrium has been estimated to be 14.4. Electron transfer to the central metal ion is the rate limiting step. The measurements of its temperature dependence yields an activation enthalpy of ∆H‡ = 12 kcal/mol and an entropy of activation ∆S‡ = - 30 e.u. thus indicating that the electron transfer step is a bimolecular reaction. The most likely reactant is water. The reduction reaction does not take place with appreciable reaction rates at physiological pH. Thus, when bound to a suitable ligand of the chlorin type, Mn (IV)-compounds are sufficiently stable with respect to autoxidation to play some role in biological redox reactions as postulated recently for the photoreactivation process of the water splitting system in photosynthesis.

Prolonged cultivation of the green alga Chlorella fusca under heterotrophic conditions and in the presence of sub-lethal concentrations of SAN H 6706 (4-chloro-5-(dimethylamino)-2-(α,α,α-tri-fluoro-m-tolyl)-3 (2H)-pyridazinone) leads to an accumulation of phytoene and phytofluene. The content of chlorophylls and coloured carotenoids of the cells treated with this herbicide, compared with normal untreated cells, is diminished by about 90% and 95% respectively, but the total amount of carotenoids, including colourless phytoene and phytofluene, is increased by 65%. This suggests that SAN H 6706 causes increased accumulation of carotenoids by eliminating a biosynthetic control mechanism, so that the endproducts of the biosynthetic chain no longer control the rate of precursor formation.

Red light induces in etioplasts of dark-grown barley seedlings (H ordeum vulgare L.) parallel to the formation of chlorophyll an increased synthesis of carotenoids, lipophilic benzoquinones and of vitamin K 1 . 1. Among the carotenoids red light initiates an enhanced synthesis of β-carotene, lutein, violaxanthine and neoxanthine whereas the pools of zeaxanthine and antheraxanthine are decreased. 2. The formation of plastoquinone-9, vitamin K 1 and a-tocoquinone is more enhanced than that of a-tocopherol. 3. The red light-induced changes of carotenoid and lipoquinone metabolism are similar in a qualitative sense to those obtained under continuous far-red, white or blue light. 4. In contrast to blue light, red light induces in the first hours of illumination a lower rate of chlorophyll and vitamin K 1 formation. There are also differences in the ratios of the individual pigments and lipoquinones throughout the greening period.

Photosynthesis, Rhodopseudomonas palustris, Respiration Chain, Electron Retardation, ATPase Rhodopseudomonas palustris is grown photosynthetically on thiosulfate. As pointed out earlier, the chromatophore deficient cell-free fraction S-144,000 catalyzes the thiosulfate-linked ATP-dependent reversal of electron transfer in anaerobiosis, thus providing reducing equivalents in the form of NADH. Under aerobic conditions, this fraction also catalyzes the oxidation of NADH, ferro-cytochrome c, or ascorbate. ATP, ADP, and PP i are active in retarding the aerobic electron flow. The electron retardation is stimulated by the addition of Mg 2+ due to a Mg 2+ -stimulated ATPase present. The ATPase system in S-144,000 hydrolyzes ATP, ADP, and P P i . Similarly, ATP or ADP or even PP i can function as energy sources in order to achieve the reduction of pyridine nucleotide. The ATPase turnover is diminished by NADH or NAD + . Admixture of ascorbate results in an increased ATPase activity. Exactly the enhanced amount of adenine nucleotide hydrolysis caused by the addition of ascorbate is inhibited by cyanide.

The study of the nitrogenous bases of Onopordon alexandrinum Boiss. resulted on the isolation of stachydrine and choline. The flavonoid components detected are: Luteolin-7-monoglucoside, apigenin-7-glucoside and quercetin.

Coenzyme A Thiol Esters, Cinnamic Acids Acyl-CoA derivatives of several hydroxylated cinnamic acids have been synthesized in 30 to 50% yield via a. acyl phenyl thiol esters, b. acyl N-hydroxysuccinimide esters, and c. glucocinnamoyl derivatives. Properties of the intermediates have been determined. The cinnamyol-CoA thiol esters were characterized by their chromatographic behaviour and UV spectra. The molar extinction coefficients of these important intermediates in plant phenylpropane metabolism have been unequivocally determined. Recently published values 13 for the molar extinction coefficients of these derivatives are incorrect; the methodological reason for this error has been established.

A sulfite reductase from spinach has been purified 125 fold. Throughout all stages of purification the reduction of sulfite has been found dependent on ferredoxin. Reduced ferredoxin has been provided either by photosynthetic reduction in isolated, broken chloroplasts or by NADPH via the ferredoxin-NADP-oxidoreductase. During the purification procedure ferredoxin as electrondonor has been replaced by reduced methylviologen.

Ring Only 6.7% of the whole plumage lipids of the ring dove originates from diester waxes of the uropygial gland secretion. The rest is distributed to hydrocarbons (3.3%), sterolesters and waxes (10.7%), free alcohols and sterols (5%), free fatty acids (55.6%), and unidentified material (18.7%). Among the hydrocarbons saturated odd-numbered, unbranched individuals predominate, but moreover 7-methylalkanes have been detected. The chain length of free and esterified alcohols cor­ responds to those of fatty acids where even-numbered compounds predominate. Main alcoholic component, however, is cholestanol. The origin of these lipids is discussed.

Argentation Thin-layer systems for argentation chromatography of fatty-acid esters of carotenoids have been developed. As two-dimensional reversed-phase partition system on paraffine impregnated cellulose this method permits a clear discrimination between saturated and unsaturated fatty acids. By adsorption on silver nitrate containing silica gel-G separation of carotenoid esters according to the degree of unsaturation of their fatty acids was established. With the use of known esters for comparison the fatty acids of whole carotenoid esters can be successfully analysed from minute amounts. Using these methods the carotenoid esters of pupae of Aglais urticae have been studied. The pupae contain 5.3% β-carotene, 46% lutein diester, 7.8% lutein 3-monoester, 11.7% lutein 3′-mono-ester, and 29.2% unesterified lutein. The fatty acids of the esters are linoleic acid (18:2) and linolenic acid (18:3) only. The diester fraction was composed of 70% dilinolenate, 25% linolenate-linoleate, and 5% dilinoleate. The combined monoesters consisted of 81% linolenate and 19% linoleate. The two main diesters could be isolated in a preparative scale and their structure verified by mass spectrometry. On the whole, in Aglais pupae 6.2 μg linolenic acid and 1.4 μg linoleic acid are bound to lutein. Since polyunsaturated fatty acids are of dietary origin, and represent essential factors for insect development, it is concluded, that their esterification with carotenoids may be a mode of storage comparable to the formation of glycerides.

1. The dependence on ATP concentration of ATPase activity and light scattering decrease of acto-HMM could be described at very low ionic strength by one hyperbolic adsorption isotherm with a dissociation constant of 3 × 10 -6 м. Hence the increase of ATPase activity was paralleled by a decrease in light scattering. At higher values of ionic strength ATPase activity stopped rising before HMM was completely saturated with ATP. Higher ionic strength prevented ATPase activity from further increasing when the rigor links (links between actin and nucleotide-free m yosin), which have formerly protected the ATPase against the suppressing action of higher ionic strength, have fallen below a certain amount. This protecting influence of rigor links did not require tropo-myosin-troponin. 2. For complete activation of ATPase activity by actin less actin was needed when HMM was incompletely saturated with ATP than when it was completely saturated with ATP. 3. The apparent affinity of ATP to regulated acto-HMM (which contained tropomyosin-troponin) was lower than to unregulated acto-HMM (which was devoid of tropomyosin-troponin). In the presence of rigor complexes (indicated by an incomplete decrease of light scattering) the ATPase activity of regulated acto-HMM was higher than that of unregulated acto-HMM. At increasing ATP concentrations the ATPase activity of regulated acto-HMM stopped rising at a similar degree of saturation with ATP as the ATPase activity of unregulated acto-HMM at the same ionic strength. Introduction

Noradrenaline, Dopamine, Glycolysis, Adenyl Cyclase Intraventricularly injected noradrenaline, dopamine and isoprenaline increased glycolysis as shown by the decrease in the concentration of “free” glycogen and increase in the concentration of lactate. The effects of noradrenaline and isoprenaline were reduced in mice which had been pretreated with α-methyl-p-tyrosine. ʟᴅ-Propranolol blocked the increase in glycolysis caused by noradrenaline, isoprenaline, sodium fluoride and analogues of 3,5-cyclic adenosine monophosphate. It is suggested that the results of this investigation can be explained by the various drugs and neurohormones acting on the adenyl cyclase system in vivo, either by blocking the action of the neurohormone on the membrane bound enzyme or monophosphate on glycolysis.

Juvenile Hormone, Biosynthesis, Cecropia Moth Adult 3-4 day old males of the giant silk moth H yalophora cecropia incorporate the label of [1- 14 C] propionate and [1- 14 C]butyrate in JH-I and JH-II. [1- 14 C]propionate is used for the bio­ synthesis of the hormones as an intact C 3 -unit. Three possible intermediates in the biosynthesis of JH-I-(E,E,Z)-7-ethyl-3,11-dimethyl-2,6,10-tridecatrienoic acid, its methyl ester, and the cor­ responding alcohol - were converted in low yields to the hormone. Methyl 7-ethyl-3,11-dimethyl-tridecanoate was not incorporated. Mevalonate applied to larvae before pupation was not used for the synthesis of a hypothetical JH-I precursor.

Interferon Mechanism, in vitro Translation, Viral and Cellular mRNA, Chick Embryo Fibroblasts, Vaccinia Infection The effect of interferon has been studied in a mixed cell-free protein synthesizing system. Hemo­ globin (Hb) and Encephalomyocarditis virus (EMC) -RNA can be efficiently translated in vitro in a system containing S-30 lysates or run-off ribosomes from primary chick embryo fibroblasts (CEF) and a postmicrosomal supernatant from mouse ascites cells or a ribosomal-wash preparation from rabbit reticulocytes. Ribosomes prepared from CEF pretreated with high doses of homologous inter­ feron (500 units/ml) were able to translate Hb-RNA in the presence of heterologous factors with the same efficiency as ribosomes prepared from control cells. Translation of EMC-RNA was slightly reduced if ribosomes from interferon-treated cells were used in the mixed cell-free system, confirming previous reports. No inhibitory effect caused by interferon treatment of CEF cells could be detected on in vitro translation of natural mRNAs if the cells had, in addition to interferon treatment, been infected with vaccinia virus. Possible reasons for the different observations made with our cell-free protein synthesizing system from CEF and with cell-free systems prepared from mouse cells are discussed.

Pre-irradiation starvation of exponentially growing Escherichia coli B/r Hcr + thy - trp - strain for thymine and tryptophan causes inhibition of pyrimidine dimer excision from ultraviolet damaged cells DNA. This inhibition of excision repair has not resulted in increasing ultraviolet sensitivity nor in increasing frequency of ultraviolet induced tryptophan revertants. The possible mechanisms of the non-excision repair in the prestarved cells, which is at least as accurate and effective as the whole dark repair in exponentially growing cells, are discussed.

Mg-Ca-ATPase, E. coli, Activation, Inhibition MgATP or CaATP is the substrate of the Mg-Ca-ATPase. At low Mg 2+ -or Ca 2+ -concentrations the ATPase is activated by Mg 2+ or Ca 2+ , the activator being essential for activity. At higher Mg 2+ -or Ca 2+ -concentrations the Mg-Ca-ATPase is inhibited competitively. Thus the real K m is smaller than reported in the literature. H + competes with Mg 2+ or Ca 2+ for the metal binding sites.

The K m -values of neuraminidases from different pathogenic and apathogenic microorganisms have been determined on low and high molecular substrates. The substrate specificity and the affinity to the different types of substrates in relation to the pathogenicity of the microorganisms are discussed.

A new coumarinic derivative (Poncimarin; C 19 H 22 O 5 ; m.p. 140 °C) was isolated from unripe fruits of Poncirus trifoliata L. which from spectroscopic evidences was formulated as 7-(2,3-epoxy-3-methyl butyloxy)-8-(2,3-epoxy-3-me-thyl butyl) coumarin.

In the course of the chemosystematic study of Aroliaceae and Lauraceae families, the leaf oils of some plants were investigated. The leaf oils were obtained by steam distillation of the fresh leaves. The individual constituents were isolated by column chromatography followed by preparative gas chromatography, and identified by gas chromatography and by infrared spectra.

It is shown by energy-dispersive x-ray analysis that the Müller’s bodies of Loxodidae consist of BaSO 4 . Therefore statocyst function can be assumed for these bodies. The route of biosyntheses is not yet investigated.

32 Si (β - . 0,1 MeV, half life about 280 years) has been used, as for as we are aware, for the first time in bio­ logical and biochemical experiments . 32Si was incorporated by the pathway of the silicon metabolism into shells of two diatom species (Cyclotella cryptica and Nitzschia spec.) and reisolated by dissolving the shells. Contaminating isotopes 3 H and 60 Co with 10000 times more activity were largely removed by this procedure.

In Escherichia coli, Pseudomonas aeruginosa, and A chromobacter metalcaligenes δ-aminolevulinic acid synthase and δ-aminolevulinic acid dehydratase appear to be the rate limiting enzymes of porphyrin and hemebiosynthesis. Bypassing of these enzymes by addition of 6-aminolevulinic acid or porphobilinogen results in overproduction of tetrapyrroles.