scholarly journals Keratin Fibres VII. Proteins of the Histological Components of Kangaroo Fibres

1972 ◽  
Vol 25 (5) ◽  
pp. 963 ◽  
Author(s):  
JH Bradbury ◽  
JM O'shea
Keyword(s):  
Molecular Weight ◽  
Formic Acid ◽  
Gel Filtration ◽  
Cortical Cells ◽  
Extraction Procedures ◽  
Vigorous Agitation ◽  
Keratin Fibres

Cortical cells, cuticle, and an impure sample of medulla were prepared from kangaroo fibres by vigorous agitation in formic acid at room temperatme, which control experiments show causes no degradation of soluble. high-or low-sulphur proteins. Many reductive extraction procedures were examined and the best method appears to be treatment with O� 2M thioglycollate at pH 11� 0 in 8M urea for 3 hr at 40�C, followed by coupling with iodoacetate. The high-and low-sulphur proteins from kangaroo fibres and its histological components were prepared and examined by gel filtration using Agarose in 8M urea at pH 8 with a column calibrated for measurement of molecular weight.

scholarly journals Extension of resolution and oligomerization-state studies of 2,4′-dihydroxyacetophenone dioxygenase fromAlcaligenessp. 4HAP

2015 ◽  
Vol 71 (10) ◽  
pp. 1258-1263 ◽  
Author(s):  
J. Guo ◽  
P. Erskine ◽  
A. R. Coker ◽  
J. Gor ◽  
S. J. Perkins ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Molecular Weight ◽  
Formic Acid ◽  
Analytical Ultracentrifugation ◽  
Ralstonia Eutropha ◽  
Gel Filtration ◽  
Apparent Molecular Weight ◽  
Structural Basis ◽  
Hydroxybenzoic Acid ◽  
Tetrameric Structure

The enzyme 2,4′-dihydroxyacetophenone dioxygenase (DAD) catalyses the conversion of 2,4′-dihydroxyacetophenone to 4-hydroxybenzoic acid and formic acid. This enzyme is a very unusual dioxygenase in that it cleaves a C—C bond in a substituent of the aromatic ring rather than within the ring itself. Whilst it has been shown that DAD is a tetramer in solution, the recently solved crystal structure of theAlcaligenessp. 4HAP enzyme was in fact dimeric rather than tetrameric. Since the use of limited chymotrypsinolysis, which apparently results in removal of the first 20 or so N-terminal residues of DAD, was necessary for crystallization of the protein, it was investigated whether this was responsible for the change in its oligomerization state. Gel-filtration and analytical ultracentrifugation studies were conducted, which confirmed that chymotrypsinolysed DAD has an apparent molecular weight of around 40 kDa, corresponding to a dimer. In contrast, the native enzyme has a molecular weight in the 70–80 kDa region, as expected for the tetramer. The structural basis for tetramerization has been investigated by the use of several docking servers, and the results are remarkably consistent with the tetrameric structure of a homologous cupin protein fromRalstonia eutropha(PDB entry 3ebr).

Molekulargewicht, Größe und Gestalt von Proteinen der Thylakoidmembran / Molecular Weight, Size and Shape of Thylakoid-Membrane Proteins

1971 ◽  
Vol 26 (8) ◽  
pp. 825-831 ◽  
Author(s):  
Wilhelm Menke ◽  
Hans-Georg Ruppel
Keyword(s):  
Molecular Weight ◽  
Formic Acid ◽  
Thylakoid Membrane ◽  
Gel Filtration ◽  
Water Soluble ◽  
Constant Thickness ◽  
Structural Protein ◽  
Lamellar System ◽  
Variable Diameter ◽  
Thylakoid Membrane Proteins

Chloroplasten, Membranproteine, Molekulargewicht, KonformationThe lamellar system of chloroplasts, dissolved in concentrated formic acid, may be freed from lipids by dialysis or gel filtration. The structural protein on both sides of the isoelectric region is water-soluble. The molecular weight was determined to be 470 000 at pH 3.0 - 3.4. Electron micrographs reveal disc-like particles of variable diameter but constant thickness. Particles of 100 Å diameter and 50 Å thickness are mainly observed. The limiting viscosity number [η] = 12 (ml/g) demonstrated that the particles are also anisodiametric in solution. It follows from changes in circular dichroism and infrared absorption that the conformation of the polypeptides is altered by the formic acid treatment. The structural protein can be separated into polypeptides in buffers containing dodecylsulphate, yielding a major component of molecular weight 25 000. From these experiments it may be concluded that one protein layer is contained in the thylakoid membrane which is composed of supra-molecular structural elements.

Physico-Chemical Properties of Recombinant Desulphatohirudin

1990 ◽  
Vol 63 (03) ◽  
pp. 499-504 ◽  
Author(s):  
A Electricwala ◽  
L Irons ◽  
R Wait ◽  
R J G Carr ◽  
R J Ling ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Gel Filtration ◽  
Chemical Properties ◽  
Alpha Helix ◽  
Apparent Molecular Weight ◽  
Correlation Spectroscopy ◽  
Nmr Studies ◽  
Recombinant Hirudin ◽  
Physico Chemical ◽  
Recombinant Molecule

SummaryPhysico-chemical properties of recombinant desulphatohirudin expressed in yeast (CIBA GEIGY code No. CGP 39393) were reinvestigated. As previously reported for natural hirudin, the recombinant molecule exhibited abnormal behaviour by gel filtration with an apparent molecular weight greater than that based on the primary structure. However, molecular weight estimation by SDS gel electrophoresis, FAB-mass spectrometry and Photon Correlation Spectroscopy were in agreement with the theoretical molecular weight, with little suggestion of dimer or aggregate formation. Circular dichroism studies of the recombinant molecule show similar spectra at different pH values but are markedly different from that reported by Konno et al. (13) for a natural hirudin-variant. Our CD studies indicate the presence of about 60% beta sheet and the absence of alpha helix in the secondary structure of recombinant hirudin, in agreement with the conformation determined by NMR studies (17)

Isolation and Characterization of Plasminogen Activator from Pig Leucocytes

1974 ◽  
Vol 31 (01) ◽  
pp. 072-085 ◽  
Author(s):  
M Kopitar ◽  
M Stegnar ◽  
B Accetto ◽  
D Lebez
Keyword(s):  
Molecular Weight ◽  
Plasminogen Activator ◽  
Gel Electrophoresis ◽  
Gel Filtration ◽  
Ph Optimum ◽  
Isolation And Characterization ◽  
Ph Range ◽  
Inhibition Studies ◽  
Final Purification

SummaryPlasminogen activator was isolated from disrupted pig leucocytes by the aid of DEAE chromatography, gel filtration on Sephadex G-100 and final purification on CM cellulose, or by preparative gel electrophoresis.Isolated plasminogen activator corresponds No. 3 band of the starting sample of leucocyte cells (that is composed from 10 gel electrophoretic bands).pH optimum was found to be in pH range 8.0–8.5 and the highest pH stability is between pH range 5.0–8.0.Inhibition studies of isolated plasminogen activator were performed with EACA, AMCHA, PAMBA and Trasylol, using Anson and Astrup method. By Astrup method 100% inhibition was found with EACA and Trasylol and 30% with AMCHA. PAMBA gave 60% inhibition already at concentration 10–3 M/ml. Molecular weight of plasminogen activator was determined by gel filtration on Sephadex G-100. The value obtained from 4 different samples was found to be 28000–30500.

Antiheparin Activity of Human Serum and Platelet Factor 4

1973 ◽  
Vol 30 (01) ◽  
pp. 093-105 ◽  
Author(s):  
C.H.J Sear ◽  
L Poller ◽  
F.R.C Path
Keyword(s):  
Molecular Weight ◽  
Ionic Strength ◽  
Blood Serum ◽  
Whole Blood ◽  
Platelet Rich Plasma ◽  
Gel Filtration ◽  
Normal Serum ◽  
Platelet Factor ◽  
Mean Values ◽  
Antiheparin Activity

SummaryThe antiheparin activity of normal serum has been studied by comparing the antiheparin activities of sera obtained from normal whole blood, platelet-rich plasma and platelet-’free’ plasma with a purified platelet extract during differential isoelectric precipitation and by gel filtration chromatography.The mean values for the activity of PRP-serum and PFP-serum were 106% (S.D. 11) and 10% (S.D. 3) of untreated whole blood respectively. The activity of whole blood serum, PRP serum and whole blood serum plus platelet extract precipitated under identical physical conditions, i.e. pH 7.0, I =0.008, indicating that the activities of the three samples are probably associated with PF4. PF4 precipitated from human platelet extract at pH 4.0, but this is probably due to the difference in the two biochemical environments investigated, i.e. serum and platelet extract.The gel filtration experiments revealed striking similarities between the major antiheparin activities of serum and platelet extract. At physiological pH and ionic strength both activities were associated with high molecular weight material, but at physiological pH and elevated ionic strength both activities behaved as much smaller entities of molecular weight between 25,000 and 30,000 daltons and it seems very likely that both activities are associated with the same molecule, i.e. PF4.

Soluble Fibrin Complexes and Fibrinogen Heterogeneity in Diabetes mellitus

1980 ◽  
Vol 44 (03) ◽  
pp. 130-134 ◽  
Author(s):  
E B Tsianos ◽  
N E Stathakis
Keyword(s):  
Diabetes Mellitus ◽  
Molecular Weight ◽  
Plasma Proteins ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Lower Molecular Weight ◽  
Polyacrylamide Gels ◽  
Soluble Fibrin ◽  
Α2 Macroglobulin ◽  
Patients With Diabetes

SummaryThe presence of soluble fibrin complexes (SFC) measured by gel filtration of plasma on 4% agarose columns, fibrinogen heterogeneity on 3.5% SDS-polyacrylamide gels and the concentrations of several plasma proteins were evaluated in 39 patients with diabetes mellitus (DM) and 19 matched control subjects. A small but significant increase of SFC was found in DM (p<0.01). On individual basis 51.2% of the patients had increased SFC (>M + 2 SD of the controls). Polyacrylamide gel electrophoresis of the SFC showed no evidence of cross-linking or proteolysis. Plasma clots formed in the presence of EDTA and trasylol were analysed in SDS-polyacrylamide gels in a normal and two lower molecular weight fibrin bands (band I, II, III). The percentage of band I fibrinogen was in diabetics (65.3 ± 4.7%) lower than that of the controls (71.8 ± 4.5%) (p < 0.01). Fibrinogen levels, antithrombin III, α1-antitrypsin, α2-macroglobulin and plasminogen were significantly increased in DM. We suggest that in DM there is an enhancement of intravascular fibrin formation and accelerated fibrinogen degradation to lower molecular weight forms.

The Different Forms of Antithrombin III in Serum

1977 ◽  
Vol 38 (02) ◽  
pp. 0494-0503 ◽  
Author(s):  
D. S Pepper ◽  
D Banhegyi ◽  
J. D Cash
Keyword(s):  
Molecular Weight ◽  
Affinity Chromatography ◽  
Human Serum ◽  
Degradation Product ◽  
Antithrombin Iii ◽  
Gel Filtration ◽  
Free Form ◽  
Polymeric Form ◽  
At Iii ◽  
Human Thrombin

SummaryAntithrombin III (AT III) complexes were isolated from human serum by affinity chromatography and gel filtration. In the first step of the preparation, using heparin-agarose chromatography, we observed that the complexed form of AT III bound less strongly to the gel than the free form and that about half of the AT III was free. With further purification a 2.5 × 105 molecular weight complex was isolated. Using 125I labelled human thrombin, this complex was radioactive indicating the presence of thrombin. Only in a synthetic thrombin-AT III system was a 9 × 104 molecular weight complex detected, but not in serum. These facts suggest that in serum AT III complexes may exist in a polymeric form. Also, an AT III antigen derived from the original AT III molecule, but not complexed, was isolated which may be a degradation product.Abbreviations used: AT-III, antithrombin III. Hepes, N-2-Hydroxyethylpiperazine-N-2-Ethanesulphonic acid.

In Vivo Studies on the Inhibition of Coagulation by Fractionated Heparin and by a Heparin Analogue I. Effects of Heparin Fractions

1981 ◽  
Vol 46 (03) ◽  
pp. 612-616 ◽  
Author(s):  
U Schmitz-Huebner ◽  
L Balleisen ◽  
F Asbeck ◽  
J van de Loo
Keyword(s):  
Molecular Weight ◽  
Day Treatment ◽  
Gel Filtration ◽  
Weight Fraction ◽  
In Vivo Studies ◽  
Low Molecular Weight ◽  
High Molecular Weight Fraction ◽  
Platelet Factor ◽  
Heparin Fractions

SummaryHigh and low molecular weight heparin fractions obtained by gel filtration chromatography of sodium mucosal heparin were injected subcutaneously into six healthy volunteers and compared with the unfractionated substance in a cross-over trial. Equal doses of 5,000 U were administered twice daily over a period of three days and heparin activity was repeatedly controlled before and 2, 4, 8 hrs after injection by means of the APTT, the anti-Xa clotting test and a chromogenic substrate assay. In addition, the in vivo effect of subcutaneously administered fractionated heparin on platelet function was examined on three of the volunteers. The results show that s.c. injections of the low molecular weight fraction induced markedly higher anti-Xa activity than injections of the other preparations. At the same time, APTT results did not significantly differ. Unfractionated heparin and the high molecular weight fraction enhanced ADP-induced platelet aggregation and collagen-mediated MDA production, while the low molecular weight fraction hardly affected these assays, but potently inhibited thrombin-induced MDA production. All heparin preparations stimulated the release of platelet Factor 4 in plasma. During the three-day treatment periods, no side-effects and no significant changes in the response to heparin injections were detected.

Rapid Isolation of High Molecular Weight Urokinase from Native Human Urine

1982 ◽  
Vol 47 (03) ◽  
pp. 197-202 ◽  
Author(s):  
Kurt Huber ◽  
Johannes Kirchheimer ◽  
Bernd R Binder
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Human Urine ◽  
Gel Filtration ◽  
Chain Structure ◽  
The Other ◽  
Single Chain ◽  
Apparent Homogeneity ◽  
Sequential Adsorption

SummaryUrokinase (UK) could be purified to apparent homogeneity starting from crude urine by sequential adsorption and elution of the enzyme to gelatine-Sepharose and agmatine-Sepharose followed by gel filtration on Sephadex G-150. The purified product exhibited characteristics of the high molecular weight urokinase (HMW-UK) but did contain two distinct entities, one of which exhibited a two chain structure as reported for the HMW-UK while the other one exhibited an apparent single chain structure. The purification described is rapid and simple and results in an enzyme with probably no major alterations. Yields are high enough to obtain purified enzymes for characterization of UK from individual donors.

CONJUGATED OESTROGENS. I

1963 ◽  
Vol 43 (3) ◽  
pp. 345-360 ◽  
Author(s):  
Stanley Kushinsky ◽  
Jane (Wu) Tang
Keyword(s):  
Molecular Weight ◽  
Formic Acid ◽  
Ethyl Acetate ◽  
High Molecular Weight ◽  
Secondary Amine ◽  
Aqueous Ammonia ◽  
Organic Solution ◽  
Extraneous Material

ABSTRACT A convenient and mild procedure is described in this paper whereby free and conjugated oestrogens may be extracted from urine. The extracts containing approximately 90 per cent of the oestrogens are devoid of most of the extraneous material and may be reduced in volume to less than 1/15 of that of the urine. The procedure consists of the following steps: (1) a 10 per cent (v/v) solution of a high molecular weight secondary amine (Amberlite LA-2, Rohm and Haas) in ethyl acetate is washed with formic acid and water, (2) the oestrogens in urine (acidified to pH 2 or 3 with H2SO4) are extracted with the LA-2 solution, (3) the oestrogen fraction is back-extracted from the organic solution with dilute aqueous ammonia.

Sign in / Sign up

Export Citation Format

Share Document