Search results for "rase"

Significance of pantothenate for glucose fermentation by Oenococcus oeni and for suppression of the erythritol and acetate production.

2001

The heterofermentative lactic acid bacterium Oenococcus oeni requires pantothenic acid for growth. In the presence of sufficient pantothenic acid, glucose was converted by heterolactic fermentation stoichiometrically to lactate, ethanol and CO2. Under pantothenic acid limitation, substantial amounts of erythritol, acetate and glycerol were produced by growing and resting bacteria. Production of erythritol and glycerol was required to compensate for the decreasing ethanol production and to enable the synthesis of acetate. In ribose fermentation, there were no shifts in the fermentation pattern in response to pantothenate supply. In the presence of pantothenate, growing O. oeni contained at l…

Inhibitory activity of sphingomyelin on hemolytic activity of coelomic fluid of Holothuria polii (echinodermata)

1987

Abstract The hemolytic activity of coelomic fluid from Holothuria polii is specifically inhibited by sphingomyelin. This phospholipid is the constituent of the membrane which probably interacts with the hemolysin thereby leading to the lysis.

Evidence that clustered phosphocholine head groups serve as sites for binding and assembly of an oligomeric protein pore.

2006

High susceptibility of rabbit erythrocytes toward the pore-forming action of staphylococcal alpha-toxin correlates with the presence of saturable, high affinity binding sites. All efforts to identify a protein or glycolipid receptor have failed, and the fact that liposomes composed solely of phosphatidylcholine are efficiently permeabilized adds to the enigma. A novel concept is advanced here to explain the puzzle. We propose that low affinity binding moieties can assume the role of high affinity binding sites due to their spatial arrangement in the membrane. Evidence is presented that phosphocholine head groups of sphingomyelin, clustered in sphingomyelin-cholesterol microdomains, serve th…

Enzymes involved in the dynamic equilibrium of core histone acetylation ofPhysarum polycephalum

1992

DEAE-Scpharose chromatography of extracts from plasmodia of the myxomyccte PI~.~suru~~t ,~/.~crpl~~ho~~ revealed the presence of multiple histone acetyltransferases and histonc deacctylascs. A cyloplasmic histonc acctyltransferase B, specific for histonc H4, and two nuclear acetyltransferases Al and A2 were identilied; Al acetylates all core hislones with a preference for l-13 and H2A. whereas A2 is specific for H3 and also slightly for H2B. Two hislone deacetylases. HDI and HD2, could be discriminated. They differ with respect to subslralc speciliciiy and pH dependence. For the first time the substrate specificity of histonc deacetylascs was determined using HPLC-purilicd individual core h…

Gcn5p is involved in the acetylation of histone H3 in nucleosomes.

1997

Abstract Enzymatic extracts from a gcn5 mutant and wild-type strains of Saccharomyces cerevisiae were chromatographically fractionated and the histone acetyltransferase activities compared. When free histones were used as substrate, extracts from wild-type cells showed two peaks of activity on histone H3 but extracts from gcn5 mutant cells showed only one. With nucleosomes as substrate, the histone acetyltransferase activities present in extracts from the gcn5 mutant strain were not able to modify H3 whereas wild-type cell extracts acetylated intensely this histone. The activity that acetylated nucleosome-bound H3 behaved as a 170-kDa complex. We suggest that Gcn5p represents a catalytic su…

Phosphotransferase properties of human erythrocyte phosphoglycolate phosphatase.

1982

Abstract 1. 1. Human erythrocyte phosphoglycolate phosphatase (PGP) (EC 3.1.3.18) shows transferase properties. Using p -nitrophenylphosphate ( p -NPP) as substrate, methanol, at a concentration of 4.9 M. was the most efficient phosphate acceptor tested (60% phosphate transfer). 2. 2. The branched alcohols i -propanol and i -butanol accept the phosphate better than the unbranched compounds. The acceptor potency is methanol > ethanol > i -propanol > n -propanol > i -butanol > n -butanol. 3. 3. The relative transferase activity could be demonstrated to be independent of substrate concentration, pH. and the inhibitory effect of NaF at 2 and 4 mM. 4. 4. POP shows no transferase activity towards…

"Por si las flais, ni flowers y en off": morphology of loanwords from english as idiomatic words in spanish idioms.

2020

En el presente artículo pretendemos ofrecer un análisis de la configuración formal de un tipo muy concreto de palabras idiomáticas: tres préstamos léxicos procedentes de la lengua inglesa que sobreviven insertos en locuciones españolas. Para ello, delimitaremos en primer lugar los conceptos de palabra idiomática, préstamo léxico y anglicismo. A continuación explicaremos el procedimiento metodológico para recopilar este tipo de piezas léxicas en dos diccionarios generales actuales del español, el DLE y el DEA, basado en el especial tratamiento lexicográfico que estas reciben debido a sus características, limitándonos a las unidades fraseológicas que conocemos como locuciones. Realizaremos un…

Temporal relationship between genetic and warning signal variation in the aposematic wood tiger moth (Parasemia plantaginis).

2013

Many plants and animals advertise unpalatability through warning signals in the form of colour and shape. Variation in warning signals within local populations is not expected because they are subject to directional selection. However, mounting evidence of warning signal variation within local populations suggests that other selective forces may be acting. Moreover, different selective pressures may act on the individual components of a warning signal. At present, we have a limited understanding about how multiple selection processes operate simultaneously on warning signal components, and even less about their temporal and spatial dynamics. Here, we examined temporal variation of several w…

Changes in predator community structure shifts the efficacy of two warning signals in Arctiid moths

2013

Summary 1. Polymorphism in warning coloration is puzzling because positive frequency-dependent selection by predators is expected to promote monomorphic warning signals in defended prey. 2. We studied predation on the warning-coloured wood tiger moth (Parasemia plantaginis )b y using artificial prey resembling white and yellow male colour morphs in five separate populations with different naturally occurring morph frequencies. 3. We tested whether predation favours one of the colour morphs over the other and whether that is influenced either by local, natural colour morph frequencies or predator community composition. 4. We found that yellow specimens were attacked less than white ones rega…

Maniquí blanc-i-negre = Capuchino bicolor

Altres noms vulgars: Black-and-white munia (Anglès), Capucin bicolore (Francès), Glanzelsterchen (Alemany) Gabinet de Vertebrats (Departament de Zoologia), Facultat de Ciències Biològiques (Campus de Burjassot), C/ Doctor Moliner, s/n, Bloque B. 5é plant, Burjassot (Valencia). Armari: 24-2 Valencia _