scholarly journals Purification and characterization of the seven cyanogen bromide fragments of human serum transferrin

1974 ◽  
Vol 139 (1) ◽  
pp. 163-168 ◽  
Author(s):  
Michael R. Sutton ◽  
K. Brew
Keyword(s):  
Human Serum ◽  
Cyanogen Bromide ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Sedimentation Equilibrium ◽  
High Yield ◽  
Serum Transferrin ◽  
Human Serum Transferrin ◽  
Equilibrium Ultracentrifugation

1. Procedures are described for the isolation of seven distinct cyanogen bromide fragments in high yield from human serum transferrin. 2. Cyanogen bromide-cleaved transferrin is separated into three fragments (CN-A, CN-B and CN-C) by gel filtration with Sephadex G-100. 3. Four peptides are obtained from CN-A (the largest fragment) after reduction and carboxamidomethylation, by gel filtration in acidic solvents. Two peptides are similarly obtained from fragment CN-B, whereas fragment CN-C is a single cystine-free peptide. 4. The molecular weights of the seven peptides, as determined by polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate, by sedimentation-equilibrium ultracentrifugation and by sequence studies, range from 3100 to 27000. Together they account for a molecular weight of 76200 for transferrin. 5. The two largest fragments contain the carbohydrate attachment sites of the protein, and the smallest fragment is derived from the N-terminus. 6. The amino acid compositions and N-terminal groups of the fragments are reported and the results compared with those of previous investigations.

scholarly journals Bovine lens aldehyde dehydrogenase. Purification and preliminary characterization

1983 ◽  
Vol 215 (2) ◽  
pp. 351-359 ◽  
Author(s):  
H H Ting ◽  
M J C Crabbe
Keyword(s):  
Aldehyde Dehydrogenase ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Sedimentation Equilibrium ◽  
Bovine Lens ◽  
Systemic Corticosteroids ◽  
Apparent Homogeneity ◽  
Stokes Radius ◽  
Equilibrium Ultracentrifugation

Cytoplasmic aldehyde dehydrogenase from bovine lens was purified to apparent homogeneity by using ion-exchange and affinity chromatography. Sedimentation-equilibrium ultracentrifugation, gel-filtration chromatography and sodium dodecyl sulphate/polyacrylamide-gel electrophoresis show that the enzyme is a dimer of Mr 114000, with subunits of Mr 57000. The enzyme does not dissociate into monomers in the presence of Ca2+ or Mg2+. The enzyme has a pI of 5.0, an activation energy of 35.1kJ/mmol and a pK value of 8.6 with acetaldehyde as substrate. The enzyme is a prolate ellipsoid with a Stokes radius of 4nm. Progesterone, deoxycorticosterone and chlorpropamide inhibited enzyme activity, and this inhibition may play a role in cataract formation in patients maintained on systemic corticosteroids and in tablet-dependent diabetics.

scholarly journals Amelogenins. Purification and partial characterization of proteins from developing bovine dental enamel

1973 ◽  
Vol 131 (3) ◽  
pp. 471-484 ◽  
Author(s):  
F. Michael Eggert ◽  
Grania A. Allen ◽  
Ralph C. Burgess
Keyword(s):  
Amino Acid ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Dental Enamel ◽  
Polyacrylamide Gel ◽  
Sedimentation Equilibrium ◽  
Amino Acid Compositions ◽  
Small Proteins ◽  
Equilibrium Ultracentrifugation

1. Procedures are described for the purification of amelogenin electrophoretic components and their analysis for homogeneity by polyacrylamide-gel electrophoresis at both acidic and alkaline pH values. 2. Most of these components belonged to two main groups, termed the J group and the C group after their major electrophoretic components. Sodium dodecyl sulphate-polyacrylamide-gel electrophoresis indicated that, within each group, proteins were of similar size, but the C-group proteins were larger than those of the J group. 3. By sedimentation-equilibrium ultracentrifugation and amino acid analysis, the four J-group components were found to be very small proteins (mol. wt. 5500–3000) and, except for one, similar in amino acid composition. The components of the C group were found to be proteins of moderate size (mol. wt. 16800–16100) with very similar amino acid compositions. A third minor amelogenin group of intermediate size was also found, but not further analysed. Details of the results of the ultracentrifuge studies are given in a supplementary paper that has been deposited as Supplementary Publication SUP 50014 at the National Lending Library for Science and Technology, Boston Spa, Yorks. LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1973) 131, 5. 4. Two of the J-group components were similar to amelogenins isolated by other workers. 5. All amelogenins analysed were rich in proline, glutamic acid, histidine and methionine, and contained no half-cystine. Their amino acid compositions, combined with their molecular weights, serve to distinguish the amelogenins from both collagens and keratins.

scholarly journals Dipeptidyl peptidase IV, a kidney brush-border serine peptidase

1976 ◽  
Vol 157 (1) ◽  
pp. 169-182 ◽  
Author(s):  
A J Kenny ◽  
A G Booth ◽  
S G George ◽  
J Ingram ◽  
D Kershaw ◽  
...  
Keyword(s):  
Large Subunit ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Dipeptidyl Peptidase ◽  
Dipeptidyl Peptidase Iv ◽  
Sedimentation Equilibrium ◽  
Kidney Cortex ◽  
Serine Peptidase ◽  
Microvillus Membrane

Dipeptidyl peptidase IV, an enzyme that releases dipeptides from substrates with N-terminal sequences of the forms X-Pro-Y or X-Ala-Y, was purified 300-fold from pig kidney cortex. The kidney is the main source of the enzyme, where it is one of the major microvillus-membrane proteins. Several other tissues contained demonstrable activity against the usual assay substrate glycylproline 2-naphthylamide. In the small intestine this activity was greatly enriched in the microvillus fraction. In all tissues examined, the activity was extremely sensitive to inhibition by di-isopropyl phosphorofluoridate (Dip-F), but relatively resistant to inhibition by phenylmethylsulphonyl fluoride. It is a serine proteinase which may be covalently labelled with [32P]Dip-F, and is the only enzyme of this class in the microvillus membrane. The apparent subunit mol.wt. estimated by sodium dodecyl-sulphate/polyacrylamide-gel electrophoresis and by titration with [32P]Dip-F was 130 000. Gel-filtration and sedimentation-equilibrium methods gave values in the region of 280 000, which is consistent with a dimeric structure, a conclusion supported by electron micrographs of the purified enzyme. Among other well-characterized serine proteinases, this enzyme is unique in its membrane location and its large subunit size. Investigation of the mode of attack of the peptidase on oligopeptides revealed that it could hydrolyse certain N-blocked peptides, e.g. Z-Gly-Pro-Leu-Gly-Pro. In this respect it is acting as an endopeptidase and as such may merit reclassification and renaming as microvillus-membrane serine peptidase.

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 Denaturant-induced stimulation of the beta-migrating plasminogen activator inhibitor in endothelial cells and serum

Blood ◽  
1986 ◽  
Vol 68 (6) ◽  
pp. 1298-1305 ◽  
Author(s):  
LA Erickson ◽  
CM Hekman ◽  
DJ Loskutoff
Keyword(s):  
Endothelial Cells ◽  
Sodium Dodecyl Sulfate ◽  
Human Serum ◽  
Plasminogen Activator ◽  
Serum Proteins ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Zone Electrophoresis ◽  
Dodecyl Sulfate

Cultured bovine aortic endothelial cells and human serum contain plasminogen activator inhibitors (PAIs) that are immunologically related. In the present study, the electrophoretic mobilities, molecular weights (mol wt), and activities of these PAIs were compared. When fractionated by agarose zone electrophoresis, both PAIs migrated with beta mobility as compared with the mobilities of human plasma/serum proteins. Two-dimensional electrophoretic analysis, employing agarose zone electrophoresis in the first dimension and sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the second dimension, indicated that these beta-PAIs comigrated, both having a mol wt of approximately 50,000. The activity of the PAI in endothelial cell- conditioned medium is enhanced severalfold by treatment with either sodium dodecyl sulfate or guanidine. In preliminary experiments, we were unable to stimulate the PAI activity of undiluted serum by similar treatments. However, the PAI activities in both diluted serum and gel- filtered or electrophoretically fractionated serum were enhanced by treatment with these denaturants. The gel filtration studies also revealed that serum contains multiple forms of the beta-PAI. These forms may represent polymeric PAI and/or complexes between the PAI and other serum components. These findings indicate that the primary PAIs in bovine endothelial cells and human serum are not only immunologically related but are also biochemically similar.

scholarly journals The molecular weight and properties of a neutral metallo-endopeptidase from rabbit kidney brush border

1974 ◽  
Vol 137 (3) ◽  
pp. 489-495 ◽  
Author(s):  
M. A. Kerr ◽  
A. J. Kenny
Keyword(s):  
Molecular Weight ◽  
Brush Border ◽  
Sodium Dodecyl Sulphate ◽  
Guanidine Hydrochloride ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Atomic Absorption Spectrophotometry ◽  
Sedimentation Equilibrium ◽  
Rabbit Kidney

1. Some properties of a brush-border neutral endopeptidase purified from rabbit kidney were investigated. The peptidase was assayed by its ability to hydrolyse [125I]iodoinsulin B chain. 2. The enzyme was found to be homogeneous when studied in the analytical ultracentrifuge and stained as a single glycoprotein band after electrophoresis in polyacrylamide gels. 3. The molecular weight was estimated by gel filtration in columns of Sephadex G-200, by polyacrylamide-gel electrophoresis in the presence of 2-mercapto-ethanol and sodium dodecyl sulphate and by sedimentation equilibrium in the ultra-centrifuge. The estimates fell within the range 87000–96000. The mean from two sedimentation equilibrium experiments was 93000, though this estimate may be slightly inflated because of the carbohydrate component of the enzyme. No evidence of dissociation into smaller subunits was obtained in the presence of thiol, sodium dodecyl sulphate or guanidine hydrochloride. 4. The endopeptidase was maximally active at pH6.0, although in phosphate buffer, which was strongly inhibitory, an optimum above pH8 was observed. 5. The enzyme was not affected by di-isopropyl phosphofluoridate nor by several thiol reagents. It was, however, strongly inhibited by many thiols and by EDTA and other chelating agents. 6. Although activity of the EDTA-treated enzyme could be partially restored by various bivalent metal ions, the optimum concentration for its reactivation by Zn2+ was lower than that for other ions. This metal was detected in the enzyme preparation by atomic absorption spectrophotometry in an amount equivalent to approximately one atom/mol. 7. The enzyme is the only endopeptidase shown to be located in the kidney brush border and is the first mammalian example of a neutral Zn2+- activated endopeptidase to be characterized.

scholarly journals Sequence studies concerning human serum transferrin: The primary structure of two cyanogen bromide fragments

FEBS Letters ◽  
1974 ◽  
Vol 46 (1-2) ◽  
pp. 276-280 ◽  
Author(s):  
Jacqueline Jollès ◽  
Pierre Charet ◽  
Pierre Jollès ◽  
Jean Montreuil
Keyword(s):  
Human Serum ◽  
Primary Structure ◽  
Cyanogen Bromide ◽  
Serum Transferrin ◽  
Human Serum Transferrin

scholarly journals Denaturant-induced stimulation of the beta-migrating plasminogen activator inhibitor in endothelial cells and serum

Blood ◽  
1986 ◽  
Vol 68 (6) ◽  
pp. 1298-1305 ◽  
Author(s):  
LA Erickson ◽  
CM Hekman ◽  
DJ Loskutoff
Keyword(s):  
Endothelial Cells ◽  
Sodium Dodecyl Sulfate ◽  
Human Serum ◽  
Plasminogen Activator ◽  
Serum Proteins ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Zone Electrophoresis ◽  
Dodecyl Sulfate

Abstract Cultured bovine aortic endothelial cells and human serum contain plasminogen activator inhibitors (PAIs) that are immunologically related. In the present study, the electrophoretic mobilities, molecular weights (mol wt), and activities of these PAIs were compared. When fractionated by agarose zone electrophoresis, both PAIs migrated with beta mobility as compared with the mobilities of human plasma/serum proteins. Two-dimensional electrophoretic analysis, employing agarose zone electrophoresis in the first dimension and sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the second dimension, indicated that these beta-PAIs comigrated, both having a mol wt of approximately 50,000. The activity of the PAI in endothelial cell- conditioned medium is enhanced severalfold by treatment with either sodium dodecyl sulfate or guanidine. In preliminary experiments, we were unable to stimulate the PAI activity of undiluted serum by similar treatments. However, the PAI activities in both diluted serum and gel- filtered or electrophoretically fractionated serum were enhanced by treatment with these denaturants. The gel filtration studies also revealed that serum contains multiple forms of the beta-PAI. These forms may represent polymeric PAI and/or complexes between the PAI and other serum components. These findings indicate that the primary PAIs in bovine endothelial cells and human serum are not only immunologically related but are also biochemically similar.

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