A basic protein from bovine brain that co-precipitates with tubulin in vitro

A 193 kDa protein consisting of 58 kDa subunits, which has pI values of 8.50 and 8.65, was purified from bovine brain cytosol. It formed heavy precipitates with tubulin, and the molar ratio of tubulin dimer to this protein in the precipitate was 3.2. In contrast to microtubules containing ordinary microtubule-associated proteins, these complexes remained stable against cold and 1 mM CaCl2.     

Purification of a membrane protein modifying the sensitivity of Na+/K+ ATPase to ouabain from a supernatant of plasma membrane treated with EDTA]

A membrane protein of M. W. 32,000 D and pI 5 has been purified from EDTA-treated plasma membrane supernatants by Page without detergents. These membranes are purified from the MF2S cell line issued from the murine plasmacytoma MOPC 173. The purified protein was able to induce a 300 fold increase in the Na+/K+ ATPase resistance to ouaba?n thus mimicking the original resistance of the enzyme to the drug.     

A basic protein from bovine brain that co-precipitates with tubulin in vitro

A 193 kDa protein consisting of 58 kDa subunits, which has pI values of 8.50 and 8.65, was purified from bovine brain cytosol. It formed heavy precipitates with tubulin, and the molar ratio of tubulin dimer to this protein in the precipitate was 3.2. In contrast to microtubules containing ordinary microtubule-associated proteins, these complexes remained stable against cold and 1 mM CaCl₂.Acknowledgments. This work was supported in part by a Grant-in-Aid for Scientific Research from the Ministry of Education, Science and Culture of Japan.     

Isoelectric variants of the principal polypeptide (p 30) of different strains of murine oncornaviruses]

The major murine oncornavirus polypeptide p 30 (30,000 daltons), which bears the conventional group-specific (gs) determinants, can be separated by isoelectric focusing into four classes, with isoelectric points (pI) of 5.5, 5.9, 6.7 and 7.1. All the Moloney stocks tested have a pI 5.9 p 30, while p 30's with three to four different pI values are found to coexist in other stocks, with the pI 6.7 form predominating in Gross virus stocks.     

Large scale isoelectric focusing analysis of the non-histone proteins of the nucleus: Isolation of components with alkaline isoelectric points

Summary After large scale isoelectric focusing of rat liver non-histone protein in polyacrylamide gel, pH range 4–8.6, the only protein material found outside the gradient was present in the cathode solution (20 mM NaOH). This was low mol. wt protein material (approximately 10,000) with an acidic amino acid composition. It bound 5–6 times its own weight of basic ampholine carrier ampholytes to give a complex with a pI of 8.82. This could be dissociated by dialysis against 1 M NaCl.We are indebted to the Yorkshire Cancer Research Campaign for financial support for this project.     

Molecular forms of human leukocytic alpha-galactosidase and N-acetyl-alpha-galactosaminidase]

1. Normal human leukocytes present three molecular forms of alpha-galactosidase (EC 3.2.1.22) separated using electrofocusing: a new major form IV (pI 4.0) characteristic of leukocytes and two forms that exist in other tissues, form I (pI 4.5) and form II (pI 4.0). 2. Normal human leukocytes present only one molecular form (pI 4.5) of N-acetyl-alpha-galactosaminidase (EC 3.2.1.49) corresponding to alpha-galactosidase form II. 3. In leukocytes from patients with Fabry disease, the electrofocusing shows that the alpha-galactosidase lacking corresponds to forms I and IV, while the residual activity corresponds to form II (or N-acetyl-alpha-galactosaminidase).     

tRNase Z: the end is not in sight

Although the enzyme tRNase Z has only recently been isolated, a plethora of data has already been acquired concerning the enzyme. tRNase Z is the endonuclease that catalyzes the removal of the tRNA 3′ trailer, yielding the mature tRNA 3′ end ready for CCA addition and aminoacylation. Another substrate cleaved by tRNase Z is the small chromogenic phosphodiester bis(p-nitrophenyl)phosphate (bpNPP), which is the smallest tRNase Z substrate known so far. Hitherto the biological function as tRNA 3′-end processing enzyme has been shown only in one prokaryotic and one eukaryotic organism, respectively. This review summarizes the present information concerning the two tRNase Z substrates pre-tRNA and bpNPP, as well as the metal requirements of tRNase Z enzymes. Received 29 March 2007; received after revision 15 May 2007; accepted 21 May 2007     

Problems in the determination of isoelectric points of beta lactamases]

Analytical isoelectric focusing in polyacrylamide gels and preparative electrofocusing in density gradients may give very different pI determination for the same beta lactamase. This difference seems due to a lack of enzyme migration in some parts of the cross-linked polyacrylamide gel. This migration appears easier in density gradient isoelectricfocusing, and thus this technique yields more significant absolute pI values. Analytical isoelectric focusing should only be used for comparison studies.     

Chemical analysis of the pheromone blends produced by males and females of the neotropical moth,Mocis megas (Guénée) (Lepidoptera,Noctuidae, Catocalinae)

Summary Pheromonal secretions produced by females and males of the noctuid moth,Mocis megas (Guénée) have been analyzed by gas chromatography and mass spectrometry (EI (electron impact) and CI (chemical ionization)). The female sex pheromone was a blend of (Z,Z,Z) 3,6,9 heneicosatriene (55%) and (Z,Z) 3,6-cis-9S, 10R-epoxyheneicosadiene (45%). Male secretion produced at the level of a prothoracic organ was a blend of two unsaturated major hydrocarbons: (Z,Z) 6,9 heneicosadiene, (64%) and (Z,Z,Z) 3,6,9 heneicosatriene (24%) and C₁₉, C₂₀ and C₂₂ homologues (total ratio 12%), as minor components. The trienic hydrocarbon was present in both sexes. The behavioral role of this male secretion has not yet been elucidated.     

Isozymes of cathepsin B1 in developing human placenta

Summary Cathepsin B1 was purified from human placentas of different gestational ages and analyzed by isoelectric focusing on polyacrylamide gel. The enzyme was shown to consist of 3 or 4 isozymes with pI values between 5.1 and 5.7.     

Serotonin-stimulated protein phosphorylation in aortic smooth muscle cells

The effects of serotonin on the formation of inositol phosphates and protein phosphorylation were examined in cultured smooth muscle cells. Serotonin stimulated the formation of [3H]inositol monophosphate, [3H]inositol bisphosphate and [3H]inositol trisphosphate. This effect was prevented by 5-HT2 specific antagonist, 6-methyl-1-(1-methylethyl)ergoline-8-carboxylic acid, 2-hydroxy-1-methylpropyl ester [Z]-2-butenedioate (LY53857). Serotonin stimulated the phosphorylation of many polypeptides, among which a 20 kDa polypeptide was the most prominent. The phosphorylation was also inhibited by LY53857. LY53857 alone produced no effects on protein phosphorylation. The 20 kDa polypeptides were also phosphorylated by the addition of 12-O-tetradecanoylphorbol-13-acetate. These results suggest that serotonin stimulates protein phosphorylation through 5-HT2 receptors and possibly activates protein kinase C in intact vascular smooth muscle cells.     

Evidence for plasmidic localization of "beta-lactamase" gene in a Pseudomonas aeruginosa strain, highly resistant to carbenicillin]

Pseudomonas aeruginosa strain HL, isolated in Besan?on (France), shows a high level of resistance for carbenicillin, as proved in preliminary studies. In this paper, we report the transfer of carbenicillin resistance from Pseudomonas aeruginosa HL1 carrying helper plasmids to other strains of the same species. Comparative study of beta-lactamase activity in the HL1 strain and in the conjugated strains allows confirmation of the transfer of an R-factor from the HL1 strain: in all these strains, the beta-lactamase has the same pI (5.3) and the same Vmax (relative to benzylpenicillin) for ampicillin, carbenicillin and cephaloridin.     

Expression of a bacterial gene, cloned in the yeast, Saccharomyces cerevisiae]

Vectors allowing cloning of foreign D.N.A. in the yeast Saccharomyces cerevisiae have been recently described. We have introduced in this yeast the lac Z gene of the bacteria Escherichia coli. An active beta-galactosidase, which is absent in the recipient strain, has been detected in transformed yeast. We thus conclude that the bacterial lac Z gene is expressed in yeast. We further showed that the enzyme found in the transformed yeast is identical to the bacterial enzyme with respect to size and immunological criteria.     

Trail pheromone of the red imported fire antSolenopsis invicta (Buren)

Summary Z,Z,Z-Allofarnesene (2Z, 4Z, 6Z)-2,6,10-trimethyl-2, 4, 6, 10-dodecatetraene) was identified as the trail pheromone of the red imported fire ant by comparing chromatographic and spectral properties of the pheromone obtained from ant Dufour's glands with those of synthetic compounds.Approved as TA 16297 by the director of the Texas Agricultural Experiment Station. Supported by the Texas Department of Agriculture Interagency Contract IAC-0459 (79-81).     

Marine eicosanoids: Occurrence of 8-(R)-HETE in the starfishPatiria miniata

Summary The first isolation of 8-(R)-hydroxy-5Z, 9E, 11Z, 14Z-eicosatetraenoic acid [8-(R)-HETE] from a marine source, the pacific starfishPatiria miniata, is reported. 8-(R)-HETE occurs together with 8-(R)-hydroxy-5Z, 9E, 11Z, 14Z, 17Z-eicosapentaenoic acid.     

Selection of the relevant information set for predictive relationships analysis between time series

In time series analysis, a vector Y is often called causal for another vector X if the former helps to improve the k‐step‐ahead forecast of the latter. If this holds for k=1, vector Y is commonly called Granger‐causal for X . It has been shown in several studies that the finding of causality between two (vectors of) variables is not robust to changes of the information set. In this paper, using the concept of Hilbert spaces, we derive a condition under which the predictive relationships between two vectors are invariant to the selection of a bivariate or trivariate framework. In more detail, we provide a condition under which the finding of causality (improved predictability at forecast horizon 1) respectively non‐causality of Y for X is unaffected if the information set is either enlarged or reduced by the information in a third vector Z . This result has a practical usefulness since it provides a guidance to validate the choice of the bivariate system { X , Y } in place of { X , Y , Z }. In fact, to test the ‘goodness’ of { X , Y } we should test whether Z Granger cause X not requiring the joint analysis of all variables in { X , Y , Z }. Copyright © 2002 John Wiley & Sons, Ltd.     

Synthesis and cannabinoid receptor binding activity of conjugated triene anandamide,a novel eicosanoid

A polyenoic fatty-acid isomerase (PFI) from a red marine alga was used to convert anandamide (5Z,8Z,11Z,14Z-eicosatetraenoyl-N-ethanolamide) to the 5Z,7E,9E,14Z-eicosatetraenoyl-N-ethanolamide isomer. This novel eicosanoid, termed conjugated triene anandamide (CTA), was assessed for its ability to bind to the cannabinoid receptor in rat brain membrane preparations. CTA is a high affinity cannabimimetic substance whose novel structure provides new insight into structure-activity relationships of cannabinoid receptor ligands. These experiments illustrate the utility of enzymes isolated from marine organisms in the development of pharmacological probes.     

Regulatory steps in sex pheromone biosynthesis inMamestra brassicae L. (Lepidoptera: Noctuidae)

Summary The de novo biosynthesis of (Z)-11-hexadecenyl acetate, the most abundant pheromone component inM. brassicae, starting from acetate via palmitic acid, requires the presence of a pheromone-biosynthesis-activating neurohormone. Moreover, the conversion of palmitic acid to (Z)-11-hexadecenyl acetate is strongly dependent on the presence of the neurohormone. However, no significant dependence was found for the conversion of (Z)-11-hexadecenoic acid to (Z)-11-hexadecenyl acetate. This indicates that the neurohormonal control of pheromone biosynthesis inM. brassicae occurs at the level of palmitic acid.     

Physikalisch-chemische Untersuchungen eines komplexen Eiweisses: das lösliche Eiweiss der Augenlinse, α-Crystallin

Summary Ultracentrifugal and electrophoretic investigations of the eye lens protein -crystallin show the probability that this protein exists in the lens and in its solutions (between pH 3.5 and 9.5) in two sub-units only differing in shape: a globular and a stretched unit.

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Die betreffenden Untersuchungen wurden ausgeführt unter der Ägide der Niederländischen Stiftung für Chemische Forschung (S. O. N.) mit Unterstützung der Niederländischen Organisation für reinwissenschaftliche Forschung (Z. W. O.).