Isoelectric focusing of mosquito esterases in the presence of Triton X-100

Summary Triton X-100 improves nonspecific esterase solubilization from mosquito samples and also leads to increased resolution in an isoelectric focusing electrophoresis.Acknowledgments. This research was supported by a US Army contract/grant DAMD 17-77-C-7018, US Army Medical Research and Development Command, Washington, DC and by the Office of Naval Research.     

Physiological state of submitochondrial particles and their susceptibility to Triton X-100

Summary The solubilizing effect of Triton X-100 on beef heart submitochondrial particles (ETP_H) has been studied under various physiological conditions. Coupled, uncoupled and azide-inhibited ETP_H particles have been studied. Quantitative and qualitative differences are found in the proteins solubilized by the detergent from ETP_H particles under the various conditions tested.Acknowledgments: This work was supported in part by a grant from a Spanish Comisión Asesora para la Investigación Cientifica y Técnica. M.C. Barbero was recipient of a scholarship from the Basque Government.     

Physiological state of submitochondrial particles and their susceptibility to Triton X-100

The solubilizing effect of Triton X-100 on beef heart submitochondrial particles (ETPH) has been studied under various physiological conditions. Coupled, uncoupled and azide-inhibited ETPH particles have been studied. Quantitative and qualitative differences are found in the proteins solubilized by the detergent from ETPH particles under the various conditions tested.     

Cytoplasmic contaminants in Triton X-100 washed rat liver nuclei - a possible way of further purification.

The presence of cytoplasmic contaminants is demonstrated in preparations of rat liver nuclei, even after washing with Triton X-100. They can be removed by incubation at 37 degrees C in a medium of low-salt concentration.     

Influence of recurrent nerve severance on haemolymph proteins inPeriplaneta americana L.

Zusammenfassung Es wird gezeigt, dass bei der weiblichen SchabePeriplaneta americana Durchtrennung des Nervus recurrens zu einer Reduktion der Hämolymphproteine führt.     

Purification of solubilized fucosyltransferase from lamb brain using ethylagarose gel]

The glycoprotein: fucosyl-transferase of the cerebral hemispheres, assayed with desialylated fetuin as exogenous acceptor, was the most active of the protein: glycosyltransferases tested in the brain. The addition of Titron X-100 to the membrane suspension, followed by high speed centrifugation, led to a solubilization of the enzyme. The use of hydrophobic chromatography on ethylagarose gave a good purification of this solubilized fucosyl-transferase, whose homogeneity has been shown by Ultrogel AcA 22, DEAE-cellulose chromatography and disc electrophoresis.     

A study on the parameters of digestion inPeriplaneta americana L

Summary An attempt was made to provide evidence for the regulatory mechanism for digestion inPeriplaneta americana by studying possible correlations between digestive enzymes, taking midgut protease activity into considerationI wish to acknowledge Prof. J. Bahadur, Jiwaji University, Gwalior, India, for his supervision, criticism and encouragement during the course of this study. Award of Junior Research Fellowship by C.S.I.R., New Delhi is also thankfully acknowledged.     

Determination of certain physical and chemical characteristics of the activating serum factor from preparturient women and women with habitual abortions

Follow-up investigation of the blood sera from preparturient women and women with habitual abortions showed the presence of a factor which has an activating effect on smooth muscle preparations because it causes the release of prostaglandins. Gel-chromatographic counter flow separation and microelectrophoresis of the blood sera have shown that the isolated serum factor is a water soluble glycopeptide with a molecular weight of about 2000.     

Determination of certain physical and chemical characteristics of the activating serum factor from preparturient women and women with habitual abortions

Summary Follow-up investigation of the blood sera from preparturient women and women with habitual, abortions showed the presence of a factor which has an activating effect on smooth muscle preparations because it causes the release of prostaglandins. Gel-chromatographic counter flow separation and microelectrophoresis of the blood sera have shown that the isolated serum factor is a water soluble glycopeptide with a molecular weight of about 2000.     

A method for the electrical stimulation and registration of the contractions of an isolated skeletal muscle ofPeriplaneta americana L.

Zusammenfassung Eine einfache Methode der elektrischen Reizung eines isolierten Extensormuskels (vom Bein der KüchenschabePeriplaneta americana L.) wurde beschrieben. Die Methode eignet sich zum Studium des Einflusses von Giften.     

A dynamic view of peptides and proteins in membranes

Biological membranes are highly dynamic supramolecular arrangements of lipids and proteins, which fulfill key cellular functions. Relatively few high-resolution membrane protein structures are known to date, although during recent years the structural databases have expanded at an accelerated pace. In some instances the structures of reaction intermediates provide a stroboscopic view on the conformational changes involved in protein function. Other biophysical approaches add dynamic aspects and allow one to investigate the interactions with the lipid bilayers. Membrane-active peptides fulfill many important functions in nature as they act as antimicrobials, channels, transporters or hormones, and their studies have much increased our understanding of polypeptide-membrane interactions. Interestingly several proteins have been identified that interact with the membrane as loose arrays of domains. Such conformations easily escape classical high-resolution structural analysis and the lessons learned from peptides may therefore be instructive for our understanding of the functioning of such membrane proteins. Received 11 March 2008; received after revision 2 May 2008; accepted 5 May 2008     

Paper electrophoresis of cytoplasmic proteins from normal and pathological liver cells

Riassunto Viene studiato il comportamento elettroforetico su carta delle proteine cellulari di fegato normale ed in degenerazione vacuolare e grassa. Nei ferogrammi di fegati in degenerazione vacuolare si ha la comparsa di una banda di tipo albuminico, che non compare nei ferogrammi normali. I ferogrammi di fegati in degenerazione grassa si rivelano più semplici di quelli normali per la mancanza di una banda di tipo globulinico. Questi risultati vengono brevemente discussi.

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This investigation was aided by a grant from the Consiglio Nazionale delle Ricerche.