Search results for "TYR"

Polyphenoloxidase from Riesling and Dornfelder wine grapes (Vitis vinifera) is a tyrosinase.

2015

Abstract Polyphenoloxidases (PPO) of the type-3 copper protein family are considered to be catecholoxidases catalyzing the oxidation of o-diphenols to their corresponding quinones. PPO from Grenache grapes has recently been reported to display only diphenolase activity. In contrast, we have characterized PPOs from Dornfelder and Riesling grapes which display both monophenolase and diphenolase activity. Ultracentrifugation and size exclusion chromatography indicated that both PPOs occur as monomers with Mr of about 38 kDa. Non-reducing SDS–PAGE shows two bands of about 38 kDa exhibiting strong activity. Remarkably, three bands up to 60 kDa displayed only very weak PPO activity, supporting th…

Biogenic amine production by lactic acid bacteria, acetic bacteria and yeast isolated from wine

2007

Abstract Biogenic amines are undesirable in all foods and beverages because if consumed at too high concentration, they may induce food-borne intoxications. The biogenic amine production by 155 strains of lactic acid bacteria, 40 strains of acetic bacteria and 36 strains of yeast isolated from wine were analysed in wine, grape must and synthetic media by HPLC. We did not observe biogenic amine production by acetic bacteria and yeast; however, we found production of histamine, tyramine, phenylethylamine and putrescine by LAB. A correlation of 100% was observed between biogenic amine production in synthetic medium and wine and between activity and presence of gene. With the results expose in …

Data from: Inter-annual variation and long-term trends in proportions of resident individuals in partially migratory birds

2016

Partial migration – a part of a population migrates and another part stays resident year-round on the breeding site – is probably the most common type of migration in the animal kingdom, yet it has only lately garnered more attention. Theoretical studies indicate that in partially migratory populations, the proportion of resident individuals (PoR) should increase in high latitudes in response to the warming climate, but empirical evidence exists for few species. We provide the first comprehensive overview of the environmental factors affecting PoR and the long-term trends in PoR by studying 27 common partially migratory bird species in Finland. The annual PoR values were calculated by divid…

Wee1 inhibition potentiates Wip1-dependent p53-negative tumor cell death during chemotherapy

2016

AbstractInactivation of p53 found in more than half of human cancers is often associated with increased tumor resistance to anti-cancer therapy. We have previously shown that overexpression of the phosphatase Wip1 in p53-negative tumors sensitizes them to chemotherapeutic agents, while protecting normal tissues from the side effects of anti-cancer treatment. In this study, we decided to search for kinases that prevent Wip1-mediated sensitization of cancer cells, thereby interfering with efficacy of genotoxic anti-cancer drugs. To this end, we performed a flow cytometry-based screening in order to identify kinases that regulated the levels of γH2AX, which were used as readout. Another criter…

Regulation of tyrosinase by tetrahydropteridines—What is real?

2005

Gelchromatographische refraktionierung, molekulargewichtsabhängigkeit der axialen dispersionsfunktion

1979

The knowledge of axial dispersion is necessary for the determination of molecular weight distributions from gel permeation chromatograms. This work deals with the determination of the axial dispersion function and its dependence on the molecular weight using refractionation method. The results of a number of fractionated and unfractionated samples of polystyrene reveal that peak dispersion in GPC arises mainly from diffusion in the stationary phase on the basis of the theoretical expression proposed by Kubin.

Über die möglichkeiten zur bestimmung von mischungsenthalpien und -volumina aus der molekulargewichtsabhängigkeit der kritischen entmischungstemperat…

1977

Cloud-point curves and critical curves (Tc = f(p)) have been measured for the system trans-decahydronaphthalene/polystyrene and three different molecular weights of the polystyrene component (2,5 · 106; 3,9 · 105; 1,1 · 105). It turned out that by variation of the pressure the metastable region can be investigated up to the spinodal curve. A comparison of the theta-temperatures and the enthalpy contributions χH (to the Flory-Huggins interaction parameter χ) resulting from the measured critical temperatures according to Shultz-Flory, with the corresponding directly obtained literature data, demonstrates that, although the extrapolation of Tc to infinite molecular weight is feasible, χH obtai…

Polystyrene nanoparticle-templated hollow titania nanosphere monolayers as ordered scaffolds

2018

We report a novel multi-step method for the preparation of ordered mesoporous titania scaffolds and show an illustrative example of their application to solar cells. The method is based on (monolayer) colloidal nanosphere lithography that makes use of polystyrene nanoparticles organised at a water–air interface and subsequently transferred onto a solid substrate. A titania precursor solution (titanium(IV) isopropoxide in ethanol) is then drop-cast onto the monolayer and left to “incubate” overnight. Surprisingly, instead of the expected inverse monolayer-structure, a subsequent calcination step of the precursor yields an ordered monolayer of hollow titania nanospheres with a wall thickness …

Electrophysiological and morphological properties of Cajal–Retzius cells with different ontogenetic origins

2010

International audience; The different origins of Cajal-Retzius cells (CRc) as well as their diverse molecular profile suggest that this cell type may represent different neuronal subpopulations. In order to investigate whether CRc from different origins show distinct functional or morphological characteristics we used transgenic Dbx1(cre);ROSA26(YFP) mice in which two subpopulations of CRc, originating from the septum and ventral pallium (VP) at the pallial-subpallial border (PSB), were permanently labeled by yellow fluorescent protein (YFP) expression. Electrophysiological properties of YFP(+) and YFP(-) CRc were investigated by whole-cell patch-clamp recordings, while a thorough somatoden…

Acyl-homoserine lactone production is more common among plant-associated Pseudomonas spp. than among soilborne Pseudomonas spp.

2001

ABSTRACT A total of 137 soilborne and plant-associated bacterial strains belonging to different Pseudomonas species were tested for their ability to synthesize N -acyl-homoserine lactones (NAHL). Fifty-four strains synthesized NAHL. Interestingly, NAHL production appears to be more common among plant-associated than among soilborne Pseudomonas spp. Indeed, 40% of the analyzed Pseudomonas syringae strains produced NAHL which were identified most often as the short-chain NAHL, N -hexanoyl- l -homoserine lactone, N -(3-oxo-hexanoyl)-homoserine lactone, and N -(3-oxo-octanoyl)- l -homoserine lactone (no absolute correlation between genomospecies of P. syringae and their ability to produce NAHL …