Search results for "Caliza"
showing 10 items of 656 documents
ATP distribution and localization of mitochondria in Suberites domuncula (Olivi 1792) tissue
2011
SUMMARY The metabolic energy state of sponge tissue in vivo is largely unknown. Quantitative bioluminescence-based imaging was used to analyze the ATP distribution of Suberites domuncula (Olivi 1792) tissue, in relation to differences between the cortex and the medulla. This method provides a quantitative picture of the ATP distribution closely reflecting the in vivo situation. The obtained data suggest that the highest ATP content occurs around channels in the sponge medulla. HPLC reverse-phase C-18, used for measurement of ATP content, established a value of 1.62 μmol ATP g–1 dry mass in sponge medulla, as opposed to 0.04 μmol ATP g–1 dry mass in the cortex, thus indicating a specific and…
Thermal and high-pressure stability of purified polygalacturonase and pectinmethylesterase from four different tomato processing varieties
2006
Abstract Polygalacturonase (PG) and pectinmethylesterase (PME) were extracted and purified from four tomato varieties (Galeon, Malpica, Perfectpeel and Soto) used in the processing industry. The processing stability (thermal and high pressure) of PG and PME from the four varieties was analyzed, and they all showed the same behavior. PG was present in two isoforms, PG1 (inactivated at 90 °C, 5 min) and PG2 (inactivated at 65 °C, 5 min). In contrast, PG1s and PG2s showed the same pressure stability, both can be inactivated at room temperature in the pressure range of 300–500 MPa. On the other hand, purified PMEs could be thermally inactivated (5 min, 70 °C) but 50% of its activity remained af…
From matrix clause to discourse marker: the grammaticalization of Hauptsache
2021
[EN] This paper has a double purpose. On the one hand, it intends to prove the existence of a discourse marker (DM) Hauptsache. This element preserves the core conceptual meaning of the homonymous noun, but differs from it with regard to its morphosyntactic and semantic features as well as to its discourse-organizing, information structuring, and modal functions. On the other hand, the emergence of Hauptsache as a discourse particle is explained on the grounds of a grammaticalization process similar to the ones described for the prototypical German DMs. Evidence drawn from a corpus of German and Austrian parliamentary protocols will show in which ways the six fundamental processes implied i…
Enzymatically modified LDL induces cathepsin H in human monocytes: potential relevance in early atherogenesis.
2003
Objective—Modification with proteases and cholesterylesterase transforms LDL to a moiety that resembles lipoproteins isolated from atherosclerotic lesions and possesses atherogenic properties. To identify changes in monocyte-derived foam cells laden with enzymatically modified LDL (E-LDL), we compared patterns of the most abundant transcripts in these cells after incubation with LDL or E-LDL.Methods and Results—Serial analyses of gene expression (SAGE) libraries were constructed from human monocytes after treatment with LDL or E-LDL. Several tags were differentially expressed in LDL-treated versus E-LDL–treated cells, whereby marked selective induction by E-LDL of cathepsin H was conspicuou…
Calcium negatively regulates meprin β activity and attenuates substrate cleavage
2015
The meprin β metalloproteinase is an important enzyme in extracellular matrix turnover, inflammation, and neurodegeneration in humans and mice. Previous studies showed a diminished cleavage of certain meprin β substrates in the presence of calcium, although the mechanism was not clear. With the help of a specific fluorogenic peptide assay and the human amyloid precursor protein as substrate, we demonstrated that the influence of calcium is most likely a direct effect on human meprin β itself. Analyzing the crystal structures of pro- and mature meprin β helped to identify a cluster of negatively charged amino acids forming a potential calcium binding site. Mutation of 2 of these residues (D2…
Secretory Pathway Research: The More Experimental Systems the Better
2012
Transient gene expression, in plant protoplasts or specific plant tissues, is a key technique in plant molecular cell biology, aimed at exploring gene products and their modifications to examine functional subdomains, their interactions with other biomolecules, and their subcellular localization. Here, we highlight some of the major advantages and potential pitfalls of the most commonly used transient gene expression models and illustrate how ectopic expression and the use of dominant mutants can provide insights into protein function.
Identification of Trans-Golgi Network Proteins in Arabidopsis thaliana Root Tissue
2014
Knowledge of protein subcellular localization assists in the elucidation of protein function and understanding of different biological mechanisms that occur at discrete subcellular niches. Organelle-centric proteomics enables localization of thousands of proteins simultaneously. Although such techniques have successfully allowed organelle protein catalogues to be achieved, they rely on the purification or significant enrichment of the organelle of interest, which is not achievable for many organelles. Incomplete separation of organelles leads to false discoveries, with erroneous assignments. Proteomics methods that measure the distribution patterns of specific organelle markers along densit…
Molecular determinants of large cargo transport into the nucleus
2020
Nucleocytoplasmic transport is tightly regulated by the nuclear pore complex (NPC). Among the thousands of molecules that cross the NPC, even very large (>15 nm) cargoes such as pathogens, mRNAs and pre-ribosomes can pass the NPC intact. For these cargoes, there is little quantitative understanding of the requirements for their nuclear import, especially the role of multivalent binding to transport receptors via nuclear localisation sequences (NLSs) and the effect of size on import efficiency. Here, we assayed nuclear import kinetics of 30 large cargo models based on four capsid-like particles in the size range of 17–36 nm, with tuneable numbers of up to 240 NLSs. We show that the requireme…
Simultaneous field-free molecular orientation and planar delocalization by THz laser pulses
2022
This study shows the unexpected and counter-intuitive possibility of simultaneously orienting a molecule while delocalizing its molecular axis in a plane in field-free conditions. The corresponding quantum states are characterized and different control strategies using shaped THz laser pulses are proposed to reach such states at zero and nonzero temperatures. The robustness against temperature effects of a simple control procedure combining a laser and a THz pulse is shown. Such control strategies can be applied not only to linear molecules but also to symmetric top molecules.
Unveiling two-dimensional discrete quantum walks dynamics via dispersion relations
2011
The discrete, or coined, quantum walk (QW) [1] is a process originally introduced as the quantum counterpart of the classical random walk (RW). In both cases there is a walker and a coin: at every time step the coin is tossed and the walker moves depending on the toss output. Unlike the RW, in the QW the walker and coin are quantum in nature what allows the coherent superpositions right/left and head/tail happen. This feature endows the QW with outstanding properties, such as making the standard deviation of the position of an initially localized walker grow linearly with time t, unlike the RW in which this growth goes as t1/2. This has strong consequences in algorithmics and is one of the …