scholarly journals Variability in the Apparent Molecular Weight of Inhibin

1985 ◽  
Vol 38 (3) ◽  
pp. 327 ◽  
Author(s):  
H WG Baker ◽  
LW Eddie ◽  
B Hudson ◽  
HD Niall
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecylsulfate ◽  
Gel Filtration ◽  
Apparent Molecular Weight ◽  
Polyacrylamide Gel ◽  
Pituitary Cells ◽  
Response Curves

An in vitro bioassay based on suppression of GnRH-stimulated FSH secretion by pituitary cells in culture was used to monitor inhibin activity after dialysis, gel filtration or polyacrylamide gel electrophoresis of protein preparations from a variety of gonadal secretions and extracts under native and dissociating conditions. The suggestion that inhibin is a peptide of molecular weight less than 5000 was not confirmed. Although some fractions of low molecular weight suppressed FSH secretion, the amount of activity was low and the dose response curves were not parallel with a standard preparation of inhibin. Under most conditions, inhibin eluted with an apparent molecular weight of about 90 000. However, gel filtration of rete testis fluid protein in I M acetic acid resulted in elution of inhibin activity with a lower apparent molecular weight and with polyacrylamide gel electrophoresis in o� 1% (w/v) sodium dodecylsulfate, the apparent molecular weight was 30 000. It is concluded that inhibin is a protein which tends to aggregate and coelute with larger molecules.

Formation of Soluble Complexes of Fibrinogen Related Material During Ancrod Infusion

1975 ◽  
Author(s):  
Caroline McKillop ◽  
W. Edgar ◽  
C. D. Forbes ◽  
C. R. M. Prentice
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Polyacrylamide Gel ◽  
Agarose Gel ◽  
Blood Samples ◽  
Related Material ◽  
Beta Alanine ◽  
Soluble Complexes

Seven pationts undergoing therapeutic defibrination by ancrod infusion were studied. Blood samples were obtained before treatment and after 6 and 24 hours ancrod infusion. Fibrinogen and its derivatives were precipitated with beta-alanine and separated by ΰ per cent agarose gel filtration. A range of soluble complexes were demonstrated after 6 hours infusion. Polyacrylamide gel electrophoresis in SDS showed that the soluble complexes were largely composed of units with molecular weight similar to a minimally degraded early Fragment X. Polyacrylamide gel electrophoresis in SDS and mercaptoethanol showed a marked loss of intact alphachain in the soluble complexes when compared with the uncomplexed material, suggesting that the soluble complexes had undergone preferential fibrinolytic digestion. It is suggested that, during ancrod therapy, FDP may be produced directly from soluble complexes rather than insoluble micro-thrombi as has been suggested previously.

Phosphorylation of prolactin and growth hormone

1992 ◽  
Vol 8 (3) ◽  
pp. 183-191 ◽  
Author(s):  
C. Arámburo ◽  
J. L. Montiel ◽  
J. A. Proudman ◽  
L. R. Berghman ◽  
C. G. Scanes
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Polyacrylamide Gel ◽  
Pituitary Cells ◽  
Charge Heterogeneity ◽  
Kinase A

ABSTRACT To determine whether GH and prolactin could be phosphorylated, turkey GH, chicken GH, chicken prolactin and turkey prolactin were incubated in vitro with the catalytic subunit of protein kinase A and [γ-32P]ATP. Phosphorylation was assessed after sodium dodecyl sulphate-polyacrylamide gel electrophoresis, Western blotting and autoradiography. Polyacrylamide electrophoresis showed that both purified native chicken GH and turkey GH were phosphorylated under the conditions employed. However, the glycosylated variant of chicken GH did not appear to be labelled. Chicken prolactin, turkey prolactin and the glycosylated variant of turkey prolactin were all intensely phosphorylated by protein kinase A. Ovine and rat prolactins could also be phosphorylated by protein kinase A. The phosphate content of different native prolactin (turkey, ovine and rat) and GH (ovine and chicken) preparations was also determined and found to be significant. Chicken pituitary cells in primary culture incorporated P in GH- and prolactin-like bands isolated by non-denaturing polyacrylamide gel electrophoresis, and this was stimulated by phorbol myristate acetate. Phosphorylation of GH and prolactin may thus explain some of the charge heterogeneity of these hormones.

Effect Of Heparin On The Thrombin-Antithrombin Reaction Product

1981 ◽  
Author(s):  
Isidore Danishefsky ◽  
Michael S Bender
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Polyacrylamide Gel ◽  
Lower Molecular Weight ◽  
Primary Complex ◽  
Synthetic Substrate ◽  
The One

The characteristics of the primary complex (C-l) formed between thrombin and antithrombin in the absence and presence of heparin, were investigated. Each of the complexes were isolated by gel-filtration of the reaction mixture on Sephadex G-100.Analyses by SDS-polyacrylamide gel electrophoresis showed that thrombin causes the successive degradation of both complexes to lower molecular weight products C-2 and C-3, respectively. C-l that was formed in the absence of heparin also undergoes spontaneous direct degradation at pH 7.5, to a complex that is similar to C-3. Additionally, this C-l dissociates very slowly to release thrombin, as demonstrated by its action on a synthetic substrate. Treatment of C-l with 1M NH2OH results in its breakdown to thrombin and antithrombin. The complex formed in the presence of heparin differs from the one formed without heparin, in that it does not exhibit any measurable dissociation and does not undergo breakdown to the C-3-type product. Moreover, whereas C-l formed in the absence of heparin is decomposed completely by 1M NH2OH, the complex formed in the presence of heparin undergoes only partial breakdown even with 2M NH2OH. Addition of heparin to C-l originally produced in the absence of heparin, has no effect on its properties.The results thus indicate that heparin influences the mode of binding between thrombin and antithrombin as well as the rate of their interaction.

Purification of a Glycoprotein from Bovine Leukemia Virus (BLV)

1977 ◽  
Vol 32 (3-4) ◽  
pp. 301-304 ◽  
Author(s):  
B. Frenzel ◽  
. R. Kaaden ◽  
M. Mussgay
Keyword(s):  
Molecular Weight ◽  
Isoelectric Focusing ◽  
Bovine Leukemia Virus ◽  
Gel Electrophoresis ◽  
Leukemia Virus ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Polyacrylamide Gel ◽  
Relative Molecular Weight ◽  
Bovine Leukosis

Abstract A precipitating antigen of bovine leukemia virus was isolated by isoelectric focusing and Sephadex gel filtration. In SDS-polyacrylamide gel electrophoresis it was found to be a homogeneous protein with a relative molecular weight of 69 000 daltons. Because of its relative molecular weight and staining characteristics it was designated as BLV gp69. A protein with the same molecular weight could also be demonstrated in BLV particles. In 34 out of 35 sera from cattle affected by enzootic bovine leukosis antibodies against gp69 were detected, whereas the sera from 197 animals, free of bovine leukosis, did not react in immunodiffusion test.

scholarly journals The purification and molecular properties of the tryptophan-sensitive 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase from Neurospora crassa

1981 ◽  
Vol 197 (2) ◽  
pp. 427-436 ◽  
Author(s):  
G A Nimmo ◽  
J R Coggins
Keyword(s):  
Molecular Weight ◽  
Neurospora Crassa ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
Polyacrylamide Gel ◽  
Sedimentation Equilibrium ◽  
Phosphate Synthase

Neurospora crassa contains three isoenzymes of 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase, which are inhibited by tyrosine, tryptophan and phenylalanine respectively, and it was estimated that the relative proportions of the total activity were 54%, 14% and 32% respectively. The tryptophan-sensitive isoenzyme was purified to homogeneity as judged by polyacrylamide-gel electrophoresis and ultracentrifugation. The tyrosine-sensitive and phenylalanine-sensitive isoenzymes were only partially purified. The three isoenzymes were completely separated from each other, however, and can be distinguished by (NH4)2SO4 fractionation, chromatography on DEAE-cellulose and Ultrogel AcA-34 and polyacrylamide-gel electrophoresis. Polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate indicated that the tryptophan-sensitive isoenzyme contained one type of subunit of molecular weight 52000. The molecular weight of the native enzyme was found to be 200000 by sedimentation-equilibrium centrifugation, indicating that the enzyme is a tetramer, and the results of cross-linking and gel-filtration studies were in agreement with this conclusion.

scholarly journals Purification of the Thy-1 molecule, a major cell-surface glycoprotein of rat thymocytes

1975 ◽  
Vol 151 (3) ◽  
pp. 685-697 ◽  
Author(s):  
M Letarte-Muirhead ◽  
A N Barclay ◽  
A F Williams
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Apparent Molecular Weight ◽  
Surface Glycoprotein ◽  
Cell Surface Glycoprotein ◽  
Lentil Lectin ◽  
Polypeptide Chains

The Thy-1-molecule, which was identified by its antigenic activities, has been purified from rat thymocytes. The purification involved preparation of crude membranes and solubilization in deoxycholate, followed by gel filtration and affinity chromatography on antibody or lectin columns. In all cases the purified molecule was a glycoprotein that did not form higher polymers and was not associated with other polypeptide chains. The Thy-1 glycoprotein could be found in two forms, one binding to lentil lectin, the other not. Both forms had the same detectable antigens and were of a similar but not identical size. After sodium dodecyl sulphate-polyacrylamide-gel electrophoresis the apparent molecular weight of Thy-1 binding to lentil lectin was 25 000, whereas that not binding to the lectin was 27 000, with heterogeneity towards forms of apparently higher molecular weight.

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