scholarly journals Fraction Bound

2020 ◽  
Author(s):  
Keyword(s):  
Fraction Bound

Species specificity and organ, cellular and subcellular localization of the 100 kDa Ras GTPase activating protein

1994 ◽  
Vol 107 (3) ◽  
pp. 427-435 ◽  
Author(s):  
P. Mollat ◽  
A. Fournier ◽  
C.Z. Yang ◽  
E. Alsat ◽  
Y. Zhang ◽  
...  
Keyword(s):  
Amino Terminus ◽  
Specific Function ◽  
Precise Localization ◽  
Cell Type ◽  
Gtpase Activating Protein ◽  
Ras Gtpase ◽  
Organ Specific ◽  
Hydrophobic Amino Acids ◽  
Species Specific ◽  
Fraction Bound

A p100-GAP isoform, generated by an alternative splicing mechanism that eliminates the 180 hydrophobic amino acids at the amino terminus of p120-GAP, has been described in human placenta, in addition to the known p120GAP and neurofibromin. This p100-GAP possesses full Ras-GTPase stimulating activity. p120-GAP is ubiquitously localized in the cytosol while the localization of p100-GAP is unknown. Here we have explored the precise localization of p100-GAP and show that p100-GAP is present only in extracts of primate placenta. It is abundant in both human and Maccaca Rhesus placentae, where it is present in far larger amounts than p120-GAP. The p100-GAP is species-specific since it was not detected in the placenta of pig, sheep, mouse or rat. p100-GAP was also found to be organ-specific, since it was not detectable in organs other than the placenta. In this connection, we substantiated our previous finding that p100-GAP is mainly localized in the trophoblasts. Both subcellular trophoblast fractionation and immunofluorescence analyses showed that this protein was distributed between the cytosol, plasma membrane and a fraction bound to the nucleus, but not inside it. This highly restrictive specificity of p100-GAP localization in relation to species, organ and cell type, confirms the extreme singularity of this protein, and strongly suggests a particular specific function in the trophoblast.

Effective digestion of casein with agar gel-entrapped cell wall fraction-bound enzymes of Aspergillus oryzae as immobilized proteases

1991 ◽  
Vol 72 (5) ◽  
pp. 379-383 ◽  
Author(s):  
Myeong-Rak Choi ◽  
Norifumi Sato ◽  
Tatsunori Yamagishi ◽  
Fumio Yamauchi
Keyword(s):  
Cell Wall ◽  
Aspergillus Oryzae ◽  
Cell Wall Fraction ◽  
Agar Gel ◽  
Fraction Bound

A simple method for the measurement of the steroid fraction bound to sex hormone binding globulin in serum

1989 ◽  
Vol 33 (2) ◽  
pp. 227-231 ◽  
Author(s):  
J.M.G. Bonfrer ◽  
P.F. Bruning ◽  
W.J. Nooijen
Keyword(s):  
Sex Hormone ◽  
Sex Hormone Binding Globulin ◽  
Hormone Binding ◽  
Simple Method ◽  
Fraction Bound

Radioenzymic determination of homocysteine in plasma and urine.

1985 ◽  
Vol 31 (4) ◽  
pp. 624-628 ◽  
Author(s):  
H Refsum ◽  
S Helland ◽  
P M Ueland
Keyword(s):  
Plasma Proteins ◽  
High Performance ◽  
Gel Filtration ◽  
Strong Acid ◽  
High Performance Liquid Chromatographic ◽  
Total Homocysteine ◽  
Liquid Chromatographic ◽  
Fraction Bound

Abstract Using a modification of the radioenzymic assay described previously (J Biol Chem 259: 2360-2364, 1984) we measured homocysteine in freshly prepared plasma and urine from volunteers. The concentration of free homocysteine--i.e., the amount measurable in plasma after deproteinization by strong acid--was 2.27 (SEM 0.11) mumol/L for 18 men and 1.95 (SEM 0.13) mumol/L for 16 women (p greater than 0.05, not significant). About 70% of the total homocysteine in human plasma was associated with plasma proteins, and was precipitated with strong acid. The concentration of protein-bound homocysteine in plasma was 6.51 (SEM 0.32) mumol/L for men and 7.29 (SEM 0.65) mumol/L for women, a significantly (p less than 0.01) different spread. Homocysteine was rapidly released from plasma proteins in the presence of a reducing agent, dithioerythritol. By gel filtration of plasma on a "high-performance" liquid-chromatographic column, albumin was shown to be the sole carrier of homocysteine in plasma. Because the fraction bound to protein as determined by this procedure equaled that obtained by precipitation of plasma proteins with acid, we conclude that homocysteine is bound to albumin in vivo. The concentration of homocysteine in urine ranged from 3.5 to 9.5 mumol/L, about 6 mumol of homocysteine being excreted per 24 h.

scholarly journals Distribution of secretory component in hepatocytes and its mode of transfer into bile

1980 ◽  
Vol 190 (3) ◽  
pp. 819-826 ◽  
Author(s):  
Barbara M. Mullock ◽  
Richard H. Hinton ◽  
Miloslav Dobrota ◽  
Jane Peppard ◽  
Eva Orlans
Keyword(s):  
Particle Size ◽  
Plasma Membrane ◽  
Electron Microscope ◽  
Immunoglobulin A ◽  
Secretory Component ◽  
The Other ◽  
Marker Enzymes ◽  
Liver Homogenates ◽  
Fraction Bound

Immunoglobin A in bile and other external secretions is mostly bound to a glycoprotein known as secretory component. This glycoprotein is not synthesized by the same cells as immunoglobulin A and is not found in blood. We now report the mechanism by which secretory component reaches the bile and describe its function in immunoglobulin A transport across the hepatocyte. Fractionation of rat liver homogenates by zonal centrifugation was followed by measurement of the amounts of secretory component in the various fractions by rocket immunoelectrophoresis. Secretory component was found in two fractions. One of these was identified as containing Golgi vesicles from its isopycnic density and appearance in the electron microscope; the other contained principally fragments of the plasma membrane of the sinusoidal face of the hepatocyte, as shown by its particle size and content of marker enzymes. Only the latter fraction bound 125I-labelled immunoglobulin A added in vitro. At 5min after intravenous injection of [14C]fucose, the secretory component in the Golgi fraction was labelled, but not that in the plasma membrane. The secretory component in the sinusoidal plasma membrane did, however, become labelled before the first labelled secretory component appeared in bile, about 30min after injection. We suggest that fucose is added to the newly synthesized secretory component in the Golgi apparatus. The secretory component then passes, with the other newly secreted glycoproteins, to the sinusoidal plasma membrane. There it remains bound but exposed to the blood and able to bind any polymeric immunoglobulin A present in serum. The secretory component then moves across the hepatocyte to the bile-canalicular face in association with the endocytic-shuttle vesicles which carry immunoglobulin A. Hence there is a lag before newly synthesized secretory component appears in bile.

Complexes of serum gamma-glutamyltransferase with apolipoproteins and immunoglobulin A.

1984 ◽  
Vol 30 (5) ◽  
pp. 631-633 ◽  
Author(s):  
Y Artur ◽  
M Wellman-Bednawska ◽  
A Jacquier ◽  
G Siest
Keyword(s):  
Enzyme Activity ◽  
Apolipoprotein B ◽  
Immunoglobulin A ◽  
Enzymic Activity ◽  
Healthy Individuals ◽  
Gamma Glutamyltransferase ◽  
Apolipoprotein A ◽  
Hepatobiliary Diseases ◽  
Fraction Bound

Abstract We have detected complexes between gamma-glutamyltransferase and apolipoproteins or immunoglobulin A in sera from patients with hepatobiliary diseases but not in sera from healthy individuals. An average of 52.4% of the enzymic activity was precipitated by antiserum against apolipoprotein A, 29.9% by antiserum against apolipoprotein B, and 9.7% by antiserum against immunoglobulin A. Fifty to 60% of the enzyme activity was inhibited in the immunoprecipitates from the transferase fraction bound to apolipoprotein A or immunoglobulin A, and 21% in the fraction bound to apolipoprotein B. We identified the complexed transferase fractions by electrophoresis.

scholarly journals Fractionation of Selected Heavy Metals in Agricultural Soils / Frakcjonowanie Wybranych Metali Ciężkich W Glebach Uprawnych

2013 ◽  
Vol 20 (1) ◽  
pp. 117-125 ◽  
Author(s):  
Szymon Różański
Keyword(s):  
Organic Matter ◽  
Significant Role ◽  
Manganese Oxides ◽  
Solid Phase ◽  
Extraction Procedure ◽  
Total Content ◽  
Residual Fraction ◽  
Geochemical Background ◽  
Fraction Bound ◽  
Iron And Manganese

Abstract The content of trace elements in soils varies widely and their mobility and availability depends not only on the total content but also on the form of in which these elements occur. The aim of this study was to determine the total content of nickel, lead, zinc and copper in soils used for agriculture, and assess the mobility and phytoavailability of these metals against a background of physical and chemical properties of these soils. In samples taken from three soil profiles (Phaeozem and 2 Fluvisols) the contents of Ni, Pb, Zn and Cu were determined using atomic absorption spectroscopy in the solutions obtained according to the protocol of modified BCR sequential extraction procedure supplemented with aqua regia digestion. The total content of the analyzed metals in most cases corresponded to the natural values, often not exceeding the geochemical background level. It was only in the one profile of the Fluvisols (Endogleyic Fluvisol) that a higher concentration of zinc and lead was noticed (especially in the surface horizon), slightly exceeding the legal limit. Among the studied metals the lowest phytoavailability was characterized by copper (exchangeable forms on average 4.73% of the total), and the highest by zinc (11.49%). Nickel was the most permanently bound with soil solid phase, and its content in the residual fraction reached 84.46% of the total. Approximately a half of the total lead content was determined as a fraction bound with iron and manganese oxides, while in the case of this metal a significant role in binding of this metal was playing organic matter (fraction bound with organic matter and sulphides - an average of 27.5%). Significant role in the binding of all investigated metals was credited to iron and manganese compounds.

Partial characterization of Aspergillus oryzae cell wall fraction-bound enzyme related to immobilized biocatalyst

1991 ◽  
Vol 72 (3) ◽  
pp. 214-216 ◽  
Author(s):  
Myeong-Rak Choi ◽  
Norifumi Sato ◽  
Tatsunori Yamagishi ◽  
Fumio Yamauchi
Keyword(s):  
Cell Wall ◽  
Aspergillus Oryzae ◽  
Partial Characterization ◽  
Cell Wall Fraction ◽  
Immobilized Biocatalyst ◽  
Fraction Bound

Interpretation of Protein-Drug Interaction through Fraction Bound and Relative Contribution of Secondary Sites

1974 ◽  
Vol 63 (9) ◽  
pp. 1423-1427 ◽  
Author(s):  
R.F. Mais ◽  
S. Keresztes-Nagy ◽  
J.F. Zaroslinski ◽  
Y.T. Oester
Keyword(s):  
Drug Interaction ◽  
Protein Drug ◽  
Relative Contribution ◽  
Fraction Bound

Hepatic Protein Binding of Folate

1974 ◽  
Vol 46 (4) ◽  
pp. 551-554
Author(s):  
R. Corrocher ◽  
G. De Sandre ◽  
M. L. Pacor ◽  
A. V. Hoffbrand
Keyword(s):  
Folic Acid ◽  
Liver Cell ◽  
The Body ◽  
Protein Fractions ◽  
Cytoplasmic Proteins ◽  
Z Protein ◽  
Related Proteins ◽  
Fraction Bound

1. Binding of tritiated folic acid to rat liver cell cytoplasmic proteins has been studied in vitro and in vivo by Sephadex G75 column chromatography. 2. Studies in vitro show that folic acid is bound mainly in the ‘Y’ and ‘Z’ protein fractions, which have previously been described as binding other organic anions, e.g. bilirubin, sulphobromophthalein. 3. At 10 min after injection of tritiated folic acid in vivo, radioactive folates in liver cytoplasm were largely bound to X and Z protein fractions, with a smaller fraction bound to the Y fraction. At 24 and 48 h, radioactive folates were bound largely to the X and Y protein fractions. 4. It is suggested that the Y and Z proteins or closely related proteins may be involved in transfer of folates from plasma to liver, the major store of folate in the body.

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