scholarly journals High-Sulphur Proteins From a-Keratins ll. Isolation and Partial Characterization of Purified Components From Mouse Hair

1976 ◽  
Vol 29 (2) ◽  
pp. 11 ◽  
Author(s):  
Robert C Marshall ◽  
JM Gillespie

The present paper continues the study of the reduced and S-carboxymethylated high-sulphur proteins from mouse hair. Fractions have been obtained in a substantially purified form by fractional precipitation with ammonium sulphate at pH 6, followed by ion exchange chromatography on cellulose phosphate at pH 2�6. Approximately 80% by weight of the high-sulphur proteins fall into the ultra-high-sulphur category (carboxymethyicysteine content greater than 26 residues per 100 residues), and they cover a molecular weight range of 17000-28000. The components show a remarkable diversity in amino acid composition; for example the contents of arginine and glycine each vary by about 3 : 1. The remainder of the proteins contain 17-20 residues per 100 residues of carboxymethyicysteine, are smaller in size (molecular weight 11 500), and also show great diversity in overall amino acid composition.

1977 ◽  
Author(s):  
E. F. Plow ◽  
T. S. Edgington

Plasmic cleavage of fibrinogen to generate fragment X partially exposes a specific cryptic molecular site, fg-Eneo. This site in the E domain of the molecule is further exposed during subsequent cleavage. We now report on localization of this site which provides an incisive marker for the structural and conformational changes associated with plasmic cleavage of fibrinogen. Fg-Eneo was stable to reduction and alkylation and the chains of the E fragment were separated by ion exchange chromatography on DEAE-cellulose. An active component was obtained and subjected to molecular exclusion chromatography on Sephadex G-50 to insure removal of intact fg-E. A fg-Eneo positive chain was recovered and identified as Eγ with respect to amino-terminal tyrosine, amino acid composition, and immunochemical analysis. The fg-Eneo site was stable to tryptic degradation, and tryptic peptides were prepared and separated by multiple molecular exclusion chromatographic steps. Final separation of two peptides of similar size was achieved on the basis of carbohydrate content by affinity chromatography on Concanavalin A. Only the active peptide was bound by the lectin. Purity and identification of the active tryptic peptide as γ36–53 was established by amino acid composition and sequence. These results establish that this region of the γ chain of fibrinogen is not present at the hydrated surface of the native molecule but that, in association with plasmic cleavage and conformational changes, this site is progressively exposed and provides a dynamic marker of the cleavage sequence.


1957 ◽  
Vol 10 (3) ◽  
pp. 384 ◽  
Author(s):  
RA Weller

Samples of bacteria and of protozoa were separated from the rumen fluids of sheep which had been fed four different types of ration. Amino acid analyses by ion-exchange chromatography were performed on hydrolysates of "whole protein" preparations of the microbial fractions.


1978 ◽  
Vol 173 (2) ◽  
pp. 633-641 ◽  
Author(s):  
R K Craig ◽  
D McIlreavy ◽  
R L Hall

1. Guinea-pig caseins A, B and C were purified free of each other by a combination of ion-exchange chromatography and gel filtration. 2. Determination of the amino acid composition showed all three caseins to contain a high proportion of proline and glutamic acid, but no cysteine. This apart, the amino acid composition of the three caseins was markedly different, though calculated divergence values suggest that some homology may exist between caseins A and B. Molecular-weight estimates based on amino acid composition were in good agreement with those based on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. 3. N-Terminal analysis showed lysine, methionine and lysine to be the N-terminal residues of caseins A, B and C respectively. 4. Two-dimensional separation of tryptic digests revealed a distinctive pattern for each casein. 5. All caseins were shown to be phosphoproteins. The casein C preparation also contained significant amounts of sialic acid, neutral and amino sugars. 6. The results suggest that each casein represents a separate gene product, and that the low-molecular-weight proteins are not the result of a post-translational cleavage of the largest. All were distinctly different from the whey protein alpha-lactalbumin.


1978 ◽  
Vol 78 (1) ◽  
pp. 49-58 ◽  
Author(s):  
H. T. KEUTMANN ◽  
G. N. HENDY ◽  
M. BOEHNERT ◽  
J. L. H. O'RIORDAN ◽  
J. T. POTTS

During the isolation of human parathyroid hormone there is an extensive loss of immunoassayable hormone over the successive extraction steps, due in part to the presence of fragments that are soluble in 4% trichloroacetic acid. These fragments are derived from both the amino- and carboxyl-terminal regions of the hormone. The hormonal fractions precipitated with trichloroacetic acid were further purified by gel filtration and ion-exchange chromatography. At the final ion-exchange purification step, some preparations of the hormone eluted in multiple fractions. When the various components were characterized separately by immunoassay, amino acid composition, enzymic cleavage and partial sequence analysis, they were found to be closely comparable, although the most acidic fraction contained a blocked terminal amino group. Extraction of a number of batches of tissue permitted revision of the amino acid composition of human parathyroid hormone. Biosynthetic studies with labelled amino acids confirmed the absence of tyrosine and the presence of phenylalanine and threonine and localized these residues to definite regions of the molecule.


1985 ◽  
Vol 31 (8) ◽  
pp. 670-674 ◽  
Author(s):  
William M. Fogarty ◽  
Catherine T. Kelly ◽  
Sunil K. Kadam

A novel α-glucosidase and a maltase were isolated from Bacillus amyloliquefaciens. The formation of both enzymes was induced by trehalose, sucrose, or lactose in the growth medium. Trehalose is by far the most efficient inducer of both systems. The α-glucosidase and maltase were separated and purified by ion-exchange chromatography on DEAE Bio-Gel A. Purified α-glucosidase hydrolysed p-nitrophenyl-α-D-glucoside, isomaltose, and isomaltotriose but sucrose, maltose, or related saccharides were not attacked. β-Glucosides and polymeric glucosides were not degraded. The optimum temperature for α-glucosidase activity was 40 °C and its pH optimum was 5.3. The molecular weight and isoelectric point (pI) of the enzyme were 27 000 and 4.6, respectively. Purified maltase attacked maltose and sucrose, while maltotriose and melezitose were hydrolysed at slower rates and p-nitrophenyl-α-D-glucoside was not degraded. Other properties of the maltase were as follows: optimum temperature for activity, 30 °C; pH optimum, 6.5; molecular weight, 64 000; and pI, 4.7.


1971 ◽  
Vol 25 (03) ◽  
pp. 580-589 ◽  
Author(s):  
M Uszynski ◽  
U Abildgaard

SummaryProcedures for the separation of two inhibitors of the activation of plasminogen to plasmin by urokinase are described. Tissue thromboplastin was removed by adsorption to Al(0H)3 gel followed by ultracentrifugation. Plasminogen, plasminogen activator, a coagulation inhibitor and hemoglobin were removed by ion exchange chromatography (CM- or DEAE-Sephadex with NaCl gradients). The minor UK inhibitor is a relative basic protein with a pI of about 5.8. The major inhibitor was purified further by isoelectric focusing, preparative electrophoresis in polyacrylamide gel, and gel filtration. This inhibitor has α1-motility, the pI is about 5.2, and the molecular weight about 100,000. It inactivates urokinase progressively, but does not inhibit streptokinase, plasmin or thrombin.


1963 ◽  
Vol 41 (3) ◽  
pp. 697-705 ◽  
Author(s):  
P. K. Datta ◽  
K. R. Hanson ◽  
D. R. Whitaker

The molecular weight of Myrothecium cellulase was estimated by the Archibald method to be approximately 49,000. No N-terminal amino acid could be detected by the Edman degradation or with fluorodinitrobenzene. Hydrazinolysis gave glycine as the C-terminal amino acid. No free sulphydryl groups could be detected in the enzyme. The amino acid composition and the fingerprint pattern after tryptic digestion were determined.


1963 ◽  
Vol 41 (1) ◽  
pp. 697-705 ◽  
Author(s):  
P. K. Datta ◽  
K. R. Hanson ◽  
D. R. Whitaker

The molecular weight of Myrothecium cellulase was estimated by the Archibald method to be approximately 49,000. No N-terminal amino acid could be detected by the Edman degradation or with fluorodinitrobenzene. Hydrazinolysis gave glycine as the C-terminal amino acid. No free sulphydryl groups could be detected in the enzyme. The amino acid composition and the fingerprint pattern after tryptic digestion were determined.


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