scholarly journals SOME PROPERTIES OF THE PROTEIN FORMING THE OUTER FIBERS OF CILIA

1968 ◽  
Vol 36 (1) ◽  
pp. 79-90 ◽  
Author(s):  
F. L. Renaud ◽  
A. J. Rowe ◽  
I. R. Gibbons
Keyword(s):  
Aqueous Solution ◽  
Molecular Weight ◽  
Amino Acid ◽  
Guanidine Hydrochloride ◽  
Sedimentation Coefficient ◽  
Tetrahymena Pyriformis ◽  
Acetone Powder ◽  
Fiber Protein ◽  
Hydrochloride Solution ◽  
Outer Fiber

Cilia were isolated from Tetrahymena pyriformis by an ethanol-calcium procedure. Solutions of outer-fiber protein were obtained either by aqueous extraction of an acetone powder of whole cilia, or by dissolving the isolated outer-fibers in 0.6 M KCl. In aqueous solution, the outer-fiber protein has a sedimentation coefficient of 6.0S and a molecular weight of 104,000 ± 14,000. In 5 M guanidine hydrochloride solution the molecular weight falls to 55,000 ± 5,000. After reduction and alkylation in 8 M urea, about 95% of the protein migrates as a single band on electrophoresis in polyacrylamide gel at pH 8.9; the migration velocity is identical with that of reduced and alkylated actin. Freshly prepared outer-fiber protein contains about 7.5 sulfhydryl groups per 55,000 g of protein. The amino acid composition of outer-fiber protein resembles that of actin, with such differences as occur being of the same order as those between actins from different species of animal.

Stability of acetylcholinesterase in guanidine hydrochloride solution

1981 ◽  
Vol 59 (7) ◽  
pp. 551-555 ◽  
Author(s):  
Faizan Ahmad
Keyword(s):  
Molecular Weight ◽  
Guanidine Hydrochloride ◽  
Sedimentation Coefficient ◽  
Conformational State ◽  
Random Coil ◽  
Aromatic Residues ◽  
Activity Measurements ◽  
Irreversible Unfolding ◽  
Hydrochloride Solution ◽  
Circular Dichroic

The irreversible unfolding of acetylcholinesterase (acetylcholine hydrolyase, EC 3.1.1.7) by guanidine hydrochloride was studied by difference spectral, circular dichroic, and enzyme activity measurements. At pH 7.0 and in 1.1 M denaturant solution, a conformational state in which enzyme is completely inactive was detected. It is identical to the native enzyme as far as sedimentation coefficient and molecular weight are concerned, but differs from the native molecule by a slight loss in secondary structure and by a small perturbation of aromatic residues. Acetylcholinesterase in concentrated guanidine hydrochloride solution containing β-mercaptoethanol dissociates and exists as a random coil of molecular weight 68 000.

Physikalische, chemische und biologische Charakterisierung von menschlichem Choriongonadotropin

1968 ◽  
Vol 23 (11) ◽  
pp. 1412-1426 ◽  
Author(s):  
H. D. Schlumberger
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Biological Activities ◽  
Guanidine Hydrochloride ◽  
Group Analysis ◽  
Residual Activity ◽  
Apparent Molecular Weight ◽  
Terminal Amino Acid ◽  
Original Activity ◽  
Terminal Amino

Purification of commercially available HCG preparations with DEAE Sephadex A 50 and Sephadex G 100 column chromatography gave homogeneous fractions having specific biological activities four fold those of the starting materials. The purified HCG has ICSH characteristics and, in high doses, a definite FSH effect is present.Chemical analysis of HCG showed it to contain 29% carbohydrates and 69% peptides. The C-terminal amino acid of the peptide chain was found to be serine, but the N-terminal amino acid could not be determined with normal methods. A molecular weight of 22000 — 27000 daltons was obtained by quantitative end group analysis. Ultracentrifugation experiments in 4 m guanidine hydrochloride gave a molecular weight of 27200 daltons, but in neutral saline solutions at HCG concentrations above 2 mg/ml the apparent molecular weight was higher and indicated dimer formation. A dissociation constant of 10-5 mol/l was estimated for the monomer-dimer equilibrium. Since biological activity is found with 0.1 to 0.5 µg, it was concluded that the HCG monomer is the active entity.The purified HCG is stable from pH 4.5 to pH 10 for 6 hours at 37 °C. At pH 2.5 only 5 to 10% of the original activity is retained. HCG is rapidly inactivated at 100 °C, but a residual activity of 6 — 10% remained after 30 minutes at 80 °C. No activity was lost after 30 minutes incubation at 60 °C.

Purification and studies of some physicochemical properties of glutamine synthetase of Neurospora crassa

1978 ◽  
Vol 56 (10) ◽  
pp. 927-933 ◽  
Author(s):  
W. S. Lin ◽  
M. Kapoor
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Glutamine Synthetase ◽  
Neurospora Crassa ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Sedimentation Coefficient ◽  
Affinity Column ◽  
Subunit Structure ◽  
Α Helix

Glutamine synthetase (EC 6.3.1.2) of Neurospora crassa was purified to near homogeneity by chromatography on a glutamate–Sepharose affinity column. Its properties, including molecular weight, subunit structure, amino acid composition, and approximate α-helix content, have been examined. In the native state, this enzyme has been demonstrated by gel filtration to be an octamer of molecular weight 360 000 and as having a sedimentation coefficient of 13.2 S by sedimentation velocity measurements. Circular dichroism spectra in the far ultraviolet range suggest an approximate α-helix content of 23–24%. The subunit generated by treatment with urea was found to be 45 000 daltons by gel filtration methods and a molecular weight of 46 000 was calculated for the monomer obtained by sodium dodecyl sulphate (SDS) treatment and electrophoresis in SDS-polyacrylamide gels. Interprotomeric cross-linking experiments, using diimidoesters, suggest the presence of two noncovalently linked tetramers comprising the native octameric structure. Amino acid analyses revealed the presence of six tryptophans, four half cystines, and nine methionine residues per monomer of 45 000 daltons.

Weitere Untersuchungen zur Aminosäuresequenz des Melittins

1969 ◽  
Vol 24 (1) ◽  
pp. 33-35 ◽  
Author(s):  
Joachim Jentsch
Keyword(s):  
Aqueous Solution ◽  
Molecular Weight ◽  
Biological Activity ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Polypeptide Chain ◽  
Optical Rotatory Dispersion ◽  
Optical Rotatory ◽  
Surface Active ◽  
Α Helix

Melittin is the (main) toxic peptide of bee venom having a molecular weight of 2840, with a known sequence (s. fig. 1). Optical rotatory dispersion of non-crystalline melittin in aqueous solution suggests that the polypeptide chain is random, although 7% α-helix has been determined. These results are in agreement with the amino acid sequence of melittin and the assumption that the biological activity is attributable to its surface active character.

scholarly journals Isolation of human β1A-globulin by modern techniques

1969 ◽  
Vol 115 (5) ◽  
pp. 897-902 ◽  
Author(s):  
P. A. Charlwood
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Amino Acid Composition ◽  
Ammonium Sulphate ◽  
Guanidine Hydrochloride ◽  
Gel Filtration ◽  
Polyacrylamide Gel ◽  
Two Dimensional ◽  
Reversible Aggregation ◽  
Satisfactory Quality

1. Human β1A-globulin was isolated from serum by precipitation with ammonium sulphate, gel filtration and electrophoresis in polyacrylamide gel. 2. The product was found by ultracentrifugation, analytical electrophoresis in polyacrylamide gel and two-dimensional immunoelectrophoresis to be of satisfactory quality for further study. 3. The amino acid composition of β1A-globulin was determined. 4. In ordinary dilute buffers near neutrality, β1A-globulin had S020,w 6·42s and M 131 000, but some reversible aggregation occurred at lower pH. In neutral 6m-guanidine hydrochloride the molecular weight was not measurably different from that in dilute buffer.

scholarly journals FURTHER CHARACTERIZATION OF BOVINE KERATOHYALIN

1972 ◽  
Vol 52 (2) ◽  
pp. 453-464 ◽  
Author(s):  
Arthur R. Ugel ◽  
William Idler
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Guanidine Hydrochloride ◽  
Polyacrylamide Gel Electrophoresis ◽  
Potassium Phosphate ◽  
Potassium Phosphate Buffer ◽  
Extraction Pattern ◽  
Ultrastructural Characteristics ◽  
Sodium Decyl Sulfate

Extraction of serial sections of cattle hoof epidermis with solutions of calcium chloride, magnesium chloride, potassium chloride, sodium chloride, guanidine hydrochloride, ammonium sulfate, and potassium phosphate buffer (pH 7.0) at varying salt concentrations demonstrates that keratohyalin (KH) is extracted by these salts at certain molarities. Under given conditions of time and temperature, each salt has a specific extraction pattern, and similar salts have similar extraction patterns. Dialysis of the salt extracts of hoof epidermis against distilled water results in the macroaggregition of KH, as assayed by histochemical methods. Although the various macroaggregates appear identical at the histochemical level, they display different ultrastructural characteristics. Polyacrylamide gel electrophoresis of the sodium decyl sulfate-solubilized macroaggregates results in the fractionation of a 20 (or more) member homologous series of oligomers. Isolation of the various oligomeric species of bovine keratohyalin and re-electrophoresis indicate that the various KH species can undergo depolymerization. Amino acid analyses of the unfractionated bovine macroaggregates and the various molecular weight species of bovine KH are similar, further demonstrating homology of the oligomers. The molecular weight of the subunit (monomer) of bovine KH is 14,955, estimated from the amino acid analyses.

scholarly journals Galactothermin, a reversibly heat-precipitable protein of human milk at neutral pH

1970 ◽  
Vol 118 (1) ◽  
pp. 181-186 ◽  
Author(s):  
A. L. Schade ◽  
R. W. Reinhart
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Human Milk ◽  
Skim Milk ◽  
Sedimentation Coefficient ◽  
Amino Acid Residues ◽  
Isolation And Purification ◽  
Neutral Ph ◽  
Polar Species ◽  
Ultracentrifugal Analysis

1. A protein, aggregating at body temperature and solubilizing when cooled, was isolated from fresh human milk at neutral pH and studied for some of its physical, chemical and immunological properties. The name `galactothermin' is proposed for this protein. 2. Isolation and purification of galactothermin involved casein removal from skim milk at pH4.64 followed by centrifugal fractionation of residual protein-containing solutions repeatedly heated and cooled between 40°C and 0°C at pH7.3. 3. The molecular weight by ultracentrifugal analysis and the minimum molecular weight by sum of amino acid residues were 11400 and 14000 respectively. The sedimentation coefficient s25,w was 1.05S and the diffusion coefficient was 7.15×10−7. Reversible aggregation is favoured by increase in protein concentration, ionic strength, temperature, time and approach to the isoionic point of 7.27 from either acidic or alkaline conditions. 4. Among the amino acid residues, proline predominates and non-polar species account for two-thirds of the total. Cysteine and cystine are absent. Analysis of galactothermin showed it to be essentially free of hexose, sialic acid, calcium and phosphate. 5. Galactothermin is antigenic in the rabbit as evidenced by the passive cutaneous anaphylaxis test. Single precipitin lines are produced in immunodiffusion tests. 6. By electrophoresis in polyacrylamide gel at pH4.0 only one sharp band is produced.

Oospora lactic lipase: Isolation and properties

1990 ◽  
Vol 55 (8) ◽  
pp. 2110-2117 ◽  
Author(s):  
Kakhramon Davranov ◽  
Mina J. Tabak ◽  
Dzhamil Ch. Diyarov ◽  
Abdumurod Sattarov ◽  
Kamola A. Gulyamova
Keyword(s):  
Aqueous Solution ◽  
Amino Acids ◽  
Amino Acid ◽  
Molecular Mass ◽  
Amino Acid Composition ◽  
Gel Filtration ◽  
Sedimentation Coefficient ◽  
Disc Electrophoresis ◽  
Composition Analysis ◽  
Sulfur Containing

Lipase (EC 3.1.1.3) of Oospora lactic UzLM-2 was purified by ammonium sulfate (0.40-0.80) fractionation, gel-filtration on Sephadex G-100, column chromatography on DEAE-Sephadex and CM-Sephadex, gel-filtration on Sephadex G-75 and was finally crystallized in concentrated aqueous solution. Crystalline preparation of the enzyme is homogeneous at disc-electrophoresis and ultracentrifugation. Sedimentation coefficient (S20w) is 3.6 S, isoelectric point (pI) at pH 4.2 and molecular mass of the enzyme is 40-43 kD. Amino acid composition analysis showed that none of sulfur-containing amino acids were detected in the crystalline enzyme, but it contains about 8% of carbohydrates and a small amount of lipids. Lipase from Oospora lactic was most active at pH 7.5 and 37 °C in olive oil, stable in the range of pH from 5.7 to 8.0 at 30-40 °C for 18 h and retained stability at 50 °C for 10 min.

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