Search results for "phosphotransfer"
showing 10 items of 53 documents
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…
Unraveling the evolutionary history of the phosphoryl-transfer chain of the phosphoenolpyruvate:phosphotransferase system through phylogenetic analys…
2007
[Background] The phosphoenolpyruvate phosphotransferase system (PTS) plays a major role in sugar transport and in the regulation of essential physiological processes in many bacteria. The PTS couples solute transport to its phosphorylation at the expense of phosphoenolpyruvate (PEP) and it consists of general cytoplasmic phosphoryl transfer proteins and specific enzyme II complexes which catalyze the uptake and phosphorylation of solutes. Previous studies have suggested that the evolution of the constituents of the enzyme II complexes has been driven largely by horizontal gene transfer whereas vertical inheritance has been prevalent in the general phosphoryl transfer proteins in some bacter…
The Effect of tRNA
2021
Transfer RNA[Ser]Sec carries multiple post-transcriptional modifications. The A37G mutation in tRNA[Ser]Sec abrogates isopentenylation of base 37 and has a profound effect on selenoprotein expression in mice. Patients with a homozygous pathogenic p.R323Q variant in tRNA-isopentenyl-transferase (TRIT1) show a severe neurological disorder, and hence we wondered whether selenoprotein expression was impaired. Patient fibroblasts with the homozygous p.R323Q variant did not show a general decrease in selenoprotein expression. However, recombinant human TRIT1R323Q had significantly diminished activities towards several tRNA substrates in vitro. We thus engineered mice conditionally deficient in Tr…
Heterodimerization of Two Pathological Mutants Enhances the Activity of Human Phosphomannomutase2
2015
The most frequent disorder of glycosylation is due to mutations in the gene encoding phosphomannomutase2 (PMM2-CDG). For this disease, which is autosomal and recessive, there is no cure at present. Most patients are composite heterozygous and carry one allele encoding an inactive mutant, R141H, and one encoding a hypomorphic mutant. Phosphomannomutase2 is a dimer. We reproduced composite heterozygosity in vitro by mixing R141H either with the wild type protein or the most common hypomorphic mutant F119L and compared the quaternary structure, the activity and the stability of the heterodimeric enzymes. We demonstrated that the activity of R141H/F119L heterodimers in vitro, which reproduces t…
Phosphoglucomutase (EC 2.7.5.1.) and adenylate kinase (EC 2.7.4.3.) typings in Koreans and Irish.
1969
PGM1 and AK phenotypes were determined in samples from Korea and Ireland. the frequencies of PGM 1 1 genes amount to 0.916 in Koreans and 0.864 in Irish. AK1 frequencies come to 0.933 in Koreans and 0.873 in Irish.
High osmolarity glycerol (HOG) signalling in Magnaporthe oryzae: Identification of MoYPD1 and its role in osmoregulation, fungicide action, and patho…
2015
AbstractThis study comprises a first functional analysis of an YPD1-homologue in filamentous phytopathogenic fungi and its role in the HOG signalling pathway. We generated a gene deletion mutant of the gene MoYPD1 in Magnaporthe oryzae and characterized the resulting mutant strain. We have shown that MoYpd1p is a component of the phosphorelay system acting in the HOG pathway due to its Y2H protein interaction with the HKs MoHik1p and MoSln1p as well as with the response regulator MoSsk1p. Fungicidal activity of fludioxonil was reported to be based on the inhibition of MoHik1p resulting in hyperactivation of the HOG signalling pathway and lethality. Western analysis proved that both, osmotic…
Development of a green fluorescent tagged strain of Aspergillus carbonarius to monitor fungal colonization in grapes.
2011
An enhanced green fluorescent protein has been used to tag an OTA-producing strain of Aspergillus carbonarius (W04-40) isolated from naturally infected grape berries. Transformation of the fungus was mediated by Agrobacterium tumefaciens. The most efficient transformation occurred when the co-cultivation was done with 104 conidia due to higher frequency of resistance colonies (894 per 104 conidia) and lower background obtained. To confirm the presence of the hph gene in hygromycin resistant colonies, 20 putative transformants were screened by PCR analysis. The hph gene was identified in all the transformants. Variation on the expression levels of the eGFP was detected among the transformant…
Differential uptake and killing potential of Campylobacter jejuni by human peripheral monocytes/macrophages
1997
The ability of Campylobacter jejuni to survive in monocytes after phagocytic uptake was tested in a new in vitro model using adherent macrophages derived from human peripheral monocytes. The cells were stimulated with cytokines before use to ensure full phagocytic and killing activity. The kinetics of uptake and killing of bacteria was followed for 72 h with 16 strains, including stool and blood isolates and laboratory adapted strains. Significant bacterial strain differences were not observed, but the viability of phagocytosed bacteria was dependent on the individual donating the macrophages. The majority of blood donors carried macrophages that killed phagocytosed Campylobacter within 24 …
Physiological relevance of the neuronal isoform of inositol-1,4,5-trisphosphate 3-kinases in mice
2020
Inositol-1,4,5-trisphosphate 3-kinase-A (ITPKA) is the neuronal isoform of ITPKs and exhibits both actin bundling and InsP3kinase activity. In addition to neurons, ITPKA is ectopically expressed in tumor cells, where its oncogenic activity increases tumor cell malignancy. In order to analyze the physiological relevance of ITPKA, here we performed a broad phenotypic screening of itpka deficient mice. Our data show that among the neurobehavioral tests analyzed, itpka deficient mice reacted faster to a hotplate, prepulse inhibition was impaired and the accelerating rotarod test showed decreased latency of itpka deficient mice to fall. These data indicate that ITPKA is involved in the regulatio…
Enzyme polymorphisms and haemoglobin variants in Greeks
1975
Several enzyme polymorphisms and hemoglobin variants were typed in a sample of n = 219 non-related Greek blood-donors. The following gene frequencies were observed: pa = 0.201, pb = 0.701, pc = 0.098;PGDA = 0.985, PGDc = 0.015; AK1 = 0.942, AK2 = 0.058; HbA = 0.988, HbS = 0.012. No polymorphic variation was seen in LDH, s-MDH, PHI, or SOD. The population genetical aspects of these results are discussed.