Distribution and Biological Availability of Reactive High Molecular Weight Phosphorus in Natural Waters in New Zealand

1980 ◽  
Vol 37 (4) ◽  
pp. 664-669 ◽  
Author(s):  
E. White ◽  
G. Payne
Keyword(s):  
Molecular Weight ◽  
New Zealand ◽  
High Molecular Weight ◽  
Natural Waters ◽  
Phosphorus Uptake ◽  
Algal Growth ◽  
Gel Chromatography ◽  
Growth Responses ◽  
Eutrophic Lakes ◽  
Reactive Phosphorus

Eutrophic lakes and many streams on the central volcanic plateau of the North Island, New Zealand, contain dissolved chemically reactive phosphorus which is not orthophosphate. Sephadex gel (G25-150) chromatograms reveal that one reactive component is of high molecular weight (MW > 5000) while a second component elutes in the same way as phosphate-phosphorus (PO4-P). The reactive high molecular weight phosphorus (RHMW-P) in streams generally forms only a small proportion of the dissolved reactive phosphorus (DRP). In some eutrophic lakes the proportion of RHMW-P in the DRP is high (70–80%). Each lake may have a characteristic distribution of the two forms of reactive phosphorus. In summer where DRP concentrations are low (<2 mg∙m−3) in lake surface waters, PO4-P seems to dominate over RHMW-P which is consistent with long 32PO4 turnover times which are found in many of the central volcanic plateau lakes. Algal growth responses to phosphorus uptake were similar for PO4-P and RHMW-P, but not all of the RHMW-P was taken up by Chlorella in bioassays. The proportion of the RHMW-P taken up by Chlorella was different for each lake examined, posing problems in relating DRP concentrations to algal growth responses in lakes.Key words: reactive phosphorus, phosphate-phosphorus, algae, Chlorella, growth, bioassay, freshwater analysis, molybdenum blue method, Sephadex gel chromatography

Biological Availability of Low Versus High Molecular Weight Reactive Phosphorus

1978 ◽  
Vol 35 (12) ◽  
pp. 1639-1643 ◽  
Author(s):  
Hans W. Paerl ◽  
Malcolm T. Downes
Keyword(s):  
Molecular Weight ◽  
New Zealand ◽  
Key Words ◽  
High Molecular Weight ◽  
Growth Response ◽  
Growth Yields ◽  
Good Growth ◽  
Biological Availability ◽  
Culture Filtrates ◽  
Reactive Phosphorus

When equivalent concentrations of reactive high molecular weight phosphorus (RHMW-P > 5000) and free orthophosphate (PO4-P) from Lake Tutaeinanga, New Zealand, were added to P-starved Chlorella cultures, free PO4 showed a faster growth response within 48 h than RHMW-P. Algal preference for PO4 over RHMW-P could also be shown by (32P)PO4 turnover experiments. After 96 h both fractions showed good growth yields. Analyses on culture filtrates indicated that all forms of reactive P had been removed. This demonstrates that RHMW-P, which reacts with "reactive P" reagents, can eventually be utilized. Key words: reactive phosphorus, orthophosphate, algae, Chlorella, growth, bioassay

Studies on Soluble Fibrin Complexes as a Function of pH

1975 ◽  
Author(s):  
Y. Benabid ◽  
E. Concord ◽  
M. Suscillon
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Gel Electrophoresis ◽  
Gel Chromatography ◽  
Agarose Gel ◽  
Monomer Mixture ◽  
Soluble Fibrin ◽  
Molecular Weights ◽  
Fibrin Monomer

Purified fibrinogen solutions, incubated with thrombin. CNBr. Sepharose, were subjected to agarose gel chromatography and eluted at different pH (6.5; 7.5; 8.5). Among high molecular weight derivatives formed by thrombin, the major component was a dimer. Gel chromatography at pH 8.5 showed a complexes peak distinct of that from fibrinogen, whereas at pH 6.5, only the fibrinogen peak appeared: fibrin monomer was eluted with fibrinogen as demonstrated by polyacrylamid gel electrophoresis 3.75% pH 8.9. SDS urea electrophoresis after reduction indicated that complexes peak contained two α-chains (α and α′). When fibrinogen was incubated with thrombin in the presence of FSF and calcium, several derivatives with higher and higher molecular weights were formed besides the dimer, and elution profiles of chromatography were identical at pH 6.5 and 8.5, thus indicating stable complexes formation. If fibrinogen-fibrin monomer mixture was subjected to FSF action at different pH, no complexes were formed at pH 6.5. These results confirm that at pH 6.5, any association was prevented.

scholarly journals Structure Analysis and Anti-Tumor and Anti-Angiogenic Activities of Sulfated Galactofucan Extracted from Sargassum thunbergii

Marine Drugs ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 52 ◽  
Author(s):  
Weihua Jin ◽  
Wanli Wu ◽  
Hong Tang ◽  
Bin Wei ◽  
Hong Wang ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Molecular Weight ◽  
High Molecular Weight ◽  
Structure Analysis ◽  
Nmr Spectra ◽  
Low Molecular Weight ◽  
Gel Chromatography ◽  
Sargassum Thunbergii ◽  
Sulfation Pattern ◽  
Fucose Content

Sulfated galactofucan (ST-2) was obtained from Sargassum thunbergii. It was then desulfated to obtain ST-2-DS, and autohydrolyzed and precipitated by ethanol to obtain the supernatant (ST-2-S) and precipitate (ST-2-C). ST-2-C was further fractionated by gel chromatography into two fractions, ST-2-H (high molecular weight) and ST-2-L (low molecular weight). Mass spectrometry (MS) of ST-2-DS was performed to elucidate the backbone of ST-2. It was shown that ST-2-DS contained a backbone of alternating galactopyranose residues (Gal)n (n ≤ 3) and fucopyranose residues (Fuc)n. In addition, ST-2-S was also determined by MS to elucidate the branches of ST-2. It was suggested that sulfated fuco-oligomers might be the branches of ST-2. Compared to the NMR spectra of ST-2-H, the spectra of ST-2-L was more recognizable. It was shown that ST-2-L contain a backbone of (Gal)n and (Fuc)n, sulfated mainly at C4 of Fuc, and interspersed with galactose (the linkages were likely to be 1→2 and 1→6). Therefore, ST-2 might contain a backbone of (Gal)n (n ≤ 3) and (Fuc)n. The sulfation pattern was mainly at C4 of fucopyranose and partially at C4 of galactopyranose, and the branches were mainly sulfated fuco-oligomers. Finally, the anti-tumor and anti-angiogenic activities of ST-2 and its derivates were determined. It was shown that the low molecular-weight sulfated galactofucan, with higher fucose content, had better anti-angiogenic and anti-tumor activities.

"Colloidal" Phosphorus Errors in Gel Chromatography

1983 ◽  
Vol 40 (10) ◽  
pp. 1614-1621 ◽  
Author(s):  
B. Kent Burnison
Keyword(s):  
Molecular Weight ◽  
Acid Hydrolysis ◽  
High Molecular Weight ◽  
Gel Chromatography ◽  
Chemical Analyses ◽  
Molybdophosphoric Acid ◽  
Molybdenum Blue ◽  
Soluble Reactive Phosphate ◽  
Colloidal Phosphorus ◽  
Hydrolysis Of

Gel chromatography has been used for the separation of 32PO4 and a high molecular weight "colloidal" 32P-labeled fraction from 32PO4-labeled lakewater. When the labeled filtrate is treated with reagents required for the molybdenum blue method for orthophosphate analysis, only a small fraction of the "colloidal" peak is hydrolyzed to orthophosphate. As the reduced molybdophosphoric acid is strongly adsorbed to the dextran gel, quantitative elution of 32PO4 can be achieved with 0.05 mol∙L−1 NaOH and 0.3% NaCl. In hardwater lakes, care must be taken to eliminate the possibility of orthophosphate precipitation at higher pH. In these lakes, it is unlikely that the discrepancy between 32PO4 bioassays and chemical analyses can be solely attributed to acid hydrolysis of "colloidal" phosphorus. Microparticulate apatite also has the potential to release soluble reactive phosphate when the acidic molybdenum blue method is used.

Factor VIII, Small Active Factor VIII Fragments, and von Willebrand Factor

1975 ◽  
Author(s):  
R. H. Wagner
Keyword(s):  
Molecular Weight ◽  
Factor Viii ◽  
High Molecular Weight ◽  
Small Molecule ◽  
Gel Chromatography ◽  
Carrier Protein ◽  
High Molecular Weight Fraction ◽  
Factor Viii Activity ◽  
Von Willebrand ◽  
Active Fragment

Factor VIII activity of human, canine, and bovine preparations is associated with a molecule of high molecular weight. These preparations dissociate almost completely in 0.25 M Ca2+, yielding a small active fragment with factor VIII activity, and a high molecular weight fraction (carrier protein) with almost no factor VIII activity. With Ca2+ absent, the small active fragment recombines with the carrier protein to form a large protein with factor VIII activity. Mixtures of normal human small active fragment with human hemophilic carrier protein give normal recombination. Comparable experiments with human von Willebrand and canine “carrier protein fractions” show no recombination. The data suggest a working model of a small active fragment(s) linked by noncovalent bonds to a carrier molecule, comprised of repeating subunits, deficient in von Willebrand’s disease.Thrombin increases the activity of factor VIII preparations or the small active fragment obtained by Ca2+ dissociation. When a factor VIII preparation is treated with thrombin and subjected to gel chromatography or ultracentrifugation, the factor VIII activity appears to be associated with a small molecule. Factor VIII activity of this small molecule is not enhanced by thrombin. These and other data will be discussed.

Antihemophilic Factor: Separation of an Active Fragment Following Dissociation by Salts or Detergents

1972 ◽  
Vol 27 (03) ◽  
pp. 502-515 ◽  
Author(s):  
W. G Owen ◽  
Robert H. Wagner
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Apparent Molecular Weight ◽  
Gel Chromatography ◽  
Factor Activity ◽  
Degree Of Dissociation ◽  
Complete Reversal ◽  
Partial Dissociation ◽  
Triton X ◽  
Antihemophilic Factor

SummaryDissociation of canine antihemophilic factor (factor VIII, molecular weight >2 × 106) by salts and detergents was studied with the use of agarose gel chromatography. The dissociated fragments retained antihemophilic factor activity. Partial dissociation occurred in 1 M or 2 M KCl, 1 M KBr, 0.25% sodium desoxycholate and 0.1% Triton X-100, but essentially no dissociation was observed in 3 M KC1. A high degree of dissociation occurred in 0.25 M CaCl2. Removal of Ca2+ before chromatographic fractionation of the preparation resulted in complete reversal of the dissociation. However, upon separation of an active, dissociated fraction from the very high molecular weight components by gel chromatography in 0.25 M CaCl2, followed by removal of Ca2+ from the fraction, no tendency toward reaggregation was seen. The apparent molecular weight of the dissociated fragment, determined by gel chromatography, is about 25,000. It is proposed that antihemophilic factor activity is associated with a molecule, of relatively low molecular weight, which in plasma or partially purified fractions is bound by electrostatic and hydrophobic bonds to a high molecular weight carrier. The activities of both dissociated and undissociated preparations were neutralized by an antibody to human antihemophilic factor. In contrast to the behavior of undissociated antihemophilic factor, the activity of the dissociated preparation was not affected by incubation with a dilute, highly purified thrombin preparation.

scholarly journals Enhancement of blood coagulation by soluble fibrin complexes.

1975 ◽  
Vol 141 (5) ◽  
pp. 944-961 ◽  
Author(s):  
M S Hansen ◽  
N U Bang ◽  
R D Barton ◽  
L E Mattler
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Biological Properties ◽  
Major Surgery ◽  
Gel Chromatography ◽  
Soluble Fibrin ◽  
Enhanced Sensitivity ◽  
Intravascular Thrombosis ◽  
Normal Plasma

We have detected a species of soluble fibrin complexes with significant biological properties. Agarose gel chromatography of normal plasma or purified fibrinogen previously incubated with small amounts of thrombin revealed the presence of a species of high molecular weight soluble fibrin complexes, which contained only small quantities of fibrinogen by immunological assays but which exhibited enhanced sensitivity to thrombin. In addition, these complexes substantially shortened the thrombin-clotting time of normal plasma and enhanced the resistance of normal plasma to heparin action. Similar thrombin-sensitive soluble fibrin complexes were demonstrated in vivo in rabbits for up to 10 min after the infusion of 50 U of thrombin. Thrombin-sensitive soluble fibrin complexes were also demonstrated in 3 of 12 patients with documented thromboembolic disease and in 2 of 20 patients after major surgery. High molecular weight soluble fibrin complexes, which exhibit enhanced thrombin sensitivity and which are capable of increasing the rate of normal fibrinogen-to-fibrin conversion by thrombin, may appear consequent to clinical thrombosis and situations involving trauma (e.g., major surgery). Such soluble complexes, although they have no proven role in the primary pathogenesis of intravascular thrombosis, may contribute to a temporary "hypercoagulable state" and may accelerate the build-up and extension of already existing thrombotic deposits.

Secretion of high-molecular-weight adrenocorticotropic hormone from a pituitary adenoma in a patient without Cushing stigmata

2004 ◽  
Vol 101 (5) ◽  
pp. 874-877 ◽  
Author(s):  
Akira Matsuno ◽  
Ryo Okazaki ◽  
Yutaka Oki ◽  
Tadashi Nagashima
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Immunohistochemical Staining ◽  
Adrenocorticotropic Hormone ◽  
Gel Chromatography ◽  
Content Type ◽  
Acth Receptor ◽  
Silent Corticotroph Adenoma ◽  
Corticotroph Adenomas ◽  
Fine Print

✓ The authors report a case in which a patient harbored a corticotroph macroadenoma that secreted biologically inactive high-molecular-weight adrenocorticotropic hormone (ACTH) as well as authentic ACTH 1–39. The secretion of the high-molecular-weight ACTH was determined using gel chromatography. The authors believe that these two molecules competed with each other at the ACTH receptor and, thus, the bioactivity of ACTH 1–39 was masked and Cushing features were not manifested in the patient. This type of silent corticotroph adenoma may be categorized as a clinically nonfunctioning adenoma. Plasmas from patients with silent corticotroph adenomas, which are identified by positive immunohistochemical staining of ACTH, should be frozen, stored, and analyzed using gel chromatography to examine whether the tumors produce and secrete high-molecular-weight ACTH.

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