Publications by authors named "Zarkadas C"

The Ssn6-Tup1 complex is a general transcriptional co-repressor formed by the interaction of Ssn6, a tetratricopeptide repeat (TPR) protein, with the Tup1 repressor. We have previously shown that the N-terminal domain of Ssn6 comprising TPRs 1 to 3 is necessary and sufficient for this interaction and that TPR1 plays critical role. In a subsequent study, we provided evidence that in the absence of Tup1, TPR1 is susceptible to proteolysis and that conformational change(s) accompany the Ssn6-Tup1 complex formation.

View Article and Find Full Text PDF

Activated Akt has been previously implicated in acting on RS domain-containing proteins. However, it has been questioned whether its action is direct or it is mediated by co-existing SR kinase activity. To address this issue we studied in detail the phosphorylation of Lamin B Receptor (LBR) by Akt.

View Article and Find Full Text PDF

We present new data about the chemical and structural characteristics of bauxite residue (BR) from Greek Al industry, using a combination of microscopic, analytical, and spectroscopic techniques. SEM-EDS indicated a homogeneous dominant "Al-Fe-Ca-Ti-Si-Na-Cr matrix", appearing at the microscale. The bulk chemical analyses showed considerable levels of Th (111 μg g(-1)), along with minor U (15 μg g(-1)), which are responsible for radioactivity (355 and 133 Bq kg(-1) for (232)Th and (238)U, respectively) with a total dose rate of 295 nGy h(-1).

View Article and Find Full Text PDF

We present the analytical features and performance of an x-ray spectroscopy end station of moderate energy resolution operating with proton-induced quasi-monochromatic x-ray beams. The apparatus was designed, installed and operated at the 5.5 MV Tandem VdG Accelerator Laboratory of the Institute of Nuclear Physics, N.

View Article and Find Full Text PDF

Background: Selenium is an essential trace element for living organisms. In many publications, researchers express concern about a possible Se deficiency in patients with end-stage chronic renal failure (ESCRF) undergoing continuous ambulatory peritoneal dialysis (CAPD). However, in a number of published articles, the data provide no evidence that patients under CAPD develop Se deficiency.

View Article and Find Full Text PDF

Amino acid determinations were carried out on 15 new northern adapted cultivars of quality protein maize (QPM) containing opaque-2 modifier genes to ascertain whether their amino acid scoring patterns could be used to select high-lysine QPM genotypes and to assess their protein quality. Total protein in these cultivars ranged from 8.0 to 10.

View Article and Find Full Text PDF

Accurate and detailed amino acid determinations were carried out on nine northern adapted soybean cultivars to ascertain whether their amino acid profiles could be used as potentially useful indices for assessing their protein quality. The cultivars were Maple Amber, Maple Donovan, Maple Glen, Maple Isle, Maple Presto, Maple Ridge, and three brown seed coat near-isogenic lines, Maple Presto Brown, Maple Ridge Brown, and Maple Arrow Brown. Their total protein and amino acid composition were compared with those of an established cultivar, Maple Arrow.

View Article and Find Full Text PDF

The objective of this study was to assess the protein quality of the myofibrillar and connective tissue proteins of chicken gizzard. Protein fractions were isolated from White Leghorn chicken gizzards and quantified by detailed amino acid analysis. This quantification involved repeated extractions of ground gizzards first with Triton X-100, then with low ionic strength imidazole-buffered saline (pH 7.

View Article and Find Full Text PDF

The alfalfa-Rhizobium meliloti symbiosis contributes a major portion of biologically fixed nitrogen to temperate zone forage crop production. Highly-purified molybdenum-iron (MoFe) and iron (Fe) nitrogenase components were obtained for the first time from extracts of R. meliloti bacteroids.

View Article and Find Full Text PDF

Formiminotransferase-cyclodeaminase is stabilized and activated approx. 40% in the presence of low concentrations (equal or less than 0.2%) of Triton X-100, possibly because the average hydrophobicity (1.

View Article and Find Full Text PDF

Intracellular and extracellular skeletal muscle protein fractions were isolated from the legs and breasts of young and adult White Leghorn chickens and quantified by detailed amino acid analysis. This involved repeated homogenization in the presence of 50 mM CaCl2, neutral phosphate-buffered saline (pH 7.4), solubilization by 2% sodium dodecyl sulfate (SDS), and centrifugation to separate all intracellular muscle proteins from the extracellular matrix.

View Article and Find Full Text PDF

The myosin, actin, and collagen contents of young and adult avian red (leg) and white (breast) skeletal muscles from White Leghorn chickens have been determined by the use of analytical chromatographic methods developed to quantify the unique amino acids that occur in these proteins. Because one mole of actin purified from the red and white muscles of Leghorn chickens and one mole of myosin contain respectively one and two moles of N tau-methylhistidine, and the molar ratio of myosin and actin in skeletal muscle is known to be 1:6, the myofibrillar myosin and actin contents of avian skeletal muscles can be determined from the amounts of protein-bound N tau-methylhistidine found in acid hydrolysates of this tissue. Actin accounts for an estimated 11.

View Article and Find Full Text PDF

Analytical single-column chromatographic methods have been developed for determining all methylated basic amino acids, isodesmosine, desmosine, the amino sugars glucosamine and galactosamine, the diastereoisomers of 5-hydroxylysine, and related compounds at picomole levels in protein and tissue hydrolysates. Complete resolution of all these unique basic amino acids as discrete peaks was achieved in 5.4 on a 50 X 0.

View Article and Find Full Text PDF

The physicochemical properties of alveolar hydatid cyst-induced amyloid (AHCA) were investigated. The AHCA was extracted from spleens, livers, and kidneys of C57BL/6J mice at 12 weeks postinfection and purified on Sephadex G-100 and G-50 gel columns. By using SDS-PAGE and isoelectric focusing techniques the purified AHCA protein showed a molecular weight (MW) of approximately 8,700 and a pI value of 5.

View Article and Find Full Text PDF

A rapid and sensitive chromatographic method is described for determining desmosine, isodesmosine, 5-hydroxylysine, tryptophan, lysinoalanine, glucosamine and galactosamine at picomole levels in protein and tissue hydrolysates. This method uses either an automated amino acid analyser with a 17.5 X 0.

View Article and Find Full Text PDF

The bifunctional folate-dependent enzyme, 10-formyltetrahydrofolate dehydrogenase-hydrolase (10-formyltetrahydrofolate: NADP+ oxidoreductase, EC 1.5.1.

View Article and Find Full Text PDF

1. Squid meal (SqM), produced by grinding and drying the whole squid (Illex illecebrosus) common to the northeast Atlantic and Mediterranean, contained 645 g protein/kg and appeared limiting with respect to lysine, methionine and cystine. 2.

View Article and Find Full Text PDF

A rapid and sensitive chromatographic method is described for the complete separation and determination of NG-methylarginine, NG,NG-dimethlarginine, NG,N'G-dimethylarginine, and related compounds in protein and muscle tissue hydrolysates. This method is designed to be used both with conventional amino acid analyzers using a single column (10 X 0.9 cm) of Durrum type DC-6A resin at 51 degrees C, one buffer system (0.

View Article and Find Full Text PDF

The thermal denaturation of bovine cardiac G-actin has been studied by ultraviolet difference spectroscopy and circular dichroism between pH 7.5 and 10.5.

View Article and Find Full Text PDF

Two groups of sheep fed a diet of hay known to produce nutritional muscular dystrophy, one group of which received selenium supplementation, were used to study the effects of selenium on the metabolism of administered L-(35S) methionine by rumen microflora. Rumen bacterial proteins of the Se supplemented sheep contained significantly higher levels of radiosulfur than the bacterial protein of the non-supplemented sheep. Of hte L-(35S) methionine present in the rumen liquor samples from Se-supplemented sheep 2 h after administration, 13.

View Article and Find Full Text PDF

A chromatographic method is described for the determination of epsilon-N-monomethyl-epsilon-N, epsilon-N-dimethyl-, and epsilon-N, epsilon-N, epsilon-N-trimethyllysines, 1-methyl-, and 3-methylhistidines, N-G, N-G-dimethyl-, and N-G, N'G-dimethylarginines, ornithine, the diastereoisomers of hydroxylysine, basic amino acids and related compounds, using Durrum type DC-6A 11.0 plus or minus 1.0 mum spherical resin.

View Article and Find Full Text PDF

Major quantitative, but not qualitative, differences in the various species of proteins in purified membranes from Streptococcus pyogenes and its stabilized L-form have been demonstrated by acidic and alkaline disc gel electrophoresis with and without urea. The fact that no significant differences in the amino acid content or composition between these two membranes could be demonstrated emphasizes that these results are probably due to changes in the relative amounts of the various species of proteins in this subcellular component. The possibility of these protein changes in the L-form membrane being related to its inability to synthesize a rigid cell wall is discussed.

View Article and Find Full Text PDF