Differences in the Pathways of Proteins Unfolding Induced by Urea and Guanidine Hydrochloride: Molten Globule State and Aggregates

It was shown that at low concentrations guanidine hydrochloride (GdnHCl) can cause aggregation of proteins in partially folded state and that fluorescent dye 1-anilinonaphthalene-8-sulfonic acid (ANS) binds with these aggregates rather than with hydrophobic clusters on the surface of protein in molten globule state. That is why the increase in ANS fluorescence intensity is often recorded in the pathway of protein denaturation by GdnHCl, but not by urea. So what was previously believed to be the molten globule state in the pathway of protein denaturation by GdnHCl, in reality, for some proteins represents the aggregates of partially folded molecules

Fluorescence Dequenching Makes Haem-Free Soluble Guanylate Cyclase Detectable in Living Cells

In cardiovascular disease, the protective NO/sGC/cGMP signalling-pathway is impaired due to a decreased pool of NO-sensitive haem-containing sGC accompanied by a reciprocal increase in NO-insensitive haem-free sGC. However, no direct method to detect cellular haem-free sGC other than its activation by the new therapeutic class of haem mimetics, such as BAY 58-2667, is available. Here we show that fluorescence dequenching, based on the interaction of the optical active prosthetic haem group and the attached biarsenical fluorophor FlAsH can be used to detect changes in cellular sGC haem status. The partly overlap of the emission spectrum of haem and FlAsH allows energy transfer from the fluorophore to the haem which reduces the intensity of FlAsH fluorescence. Loss of the prosthetic group, e.g. by oxidative stress or by replacement with the haem mimetic BAY 58-2667, prevented the energy transfer resulting in increased fluorescence. Haem loss was corroborated by an observed decrease in NO-induced sGC activity, reduced sGC protein levels, and an increased effect of BAY 58-2667. The use of a haem-free sGC mutant and a biarsenical dye that was not quenched by haem as controls further validated that the increase in fluorescence was due to the loss of the prosthetic haem group. The present approach is based on the cellular expression of an engineered sGC variant limiting is applicability to recombinant expression systems. Nevertheless, it allows to monitor sGC's redox regulation in living cells and future enhancements might be able to extend this approach to in vivo conditions

Feeding behaviour of cultured rainbow trout (Oncorhynchus mykiss)

RNA polymerase II transcribes both protein coding and non-coding RNA genes and, in yeast, different mechanisms terminate transcription of the two gene types. Transcription termination of mRNA genes is intricately coupled to cleavage and polyadenylation, whereas transcription of small nucleolar (sno)/small nuclear (sn)RNA genes is terminated by the RNA-binding proteins Nrd1, Nab3 and Sen1. The existence of an Nrd1-like pathway in humans has not yet been demonstrated. Using the U1 and U2 genes as models, we show that human snRNA genes are more similar to mRNA genes than yeast snRNA genes with respect to termination. The Integrator complex substitutes for the mRNA cleavage and polyadenylation specificity factor complex to promote cleavage and couple snRNA 3'-end processing with termination. Moreover, members of the associated with Pta1 (APT) and cleavage factor I/II complexes function as transcription terminators for human snRNA genes with little, if any, role in snRNA 3'-end processing. The gene-specific factor, proximal sequence element-binding transcription factor (PTF), helps clear the U1 and U2 genes of nucleosomes, which provides an easy passage for pol II, and the negative elongation factor facilitates termination at the end of the genes where nucleosome levels increase. Thus, human snRNA genes may use chromatin structure as an additional mechanism to promote efficient transcription termination in vivo

The collinear cluster tri-partition (CCT) of 252Cf (sf): New aspects from neutron gated data

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Exciting Interdisciplinary Physics: Quarks and Gluons Atomic Nuclei Relativity and Cosmology Biological Systems

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Study of rare modes of "Collinear Cluster Tri-partition" of <SUP>252</SUP>Cf(sf)

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A safe lithium mimetic for bipolar disorder.

Lithium is the most effective mood stabilizer for the treatment of bipolar disorder, but it is toxic at only twice the therapeutic dosage and has many undesirable side effects. It is likely that a small molecule could be found with lithium-like efficacy but without toxicity through target-based drug discovery; however, therapeutic target of lithium remains equivocal. Inositol monophosphatase is a possible target but no bioavailable inhibitors exist. Here we report that the antioxidant ebselen inhibits inositol monophosphatase and induces lithium-like effects on mouse behaviour, which are reversed with inositol, consistent with a mechanism involving inhibition of inositol recycling. Ebselen is part of the National Institutes of Health Clinical Collection, a chemical library of bioavailable drugs considered clinically safe but without proven use. Therefore, ebselen represents a lithium mimetic with the potential both to validate inositol monophosphatase inhibition as a treatment for bipolar disorder and to serve as a treatment itself