PURIFICATION AND RADIOIMMUNOASSAY OF CHICKEN GROWTH HORMONE

1977 ◽  
Vol 73 (2) ◽  
pp. 321-329 ◽  
Author(s):  
S. HARVEY ◽  
C. G. SCANES

SUMMARY Chicken growth hormone has been isolated from adenohypophysial tissue from which the glycoprotein hormones had been removed. The procedure entailed alkali extraction, ammonium sulphate precipitation and ion-exchange chromatography on DEAE-cellulose. The resulting fraction was homogeneous, active in the rat tibia bioassay and had a similar isoelectric point, molecular weight and amino acid composition to mammalian growth hormone. A specific homologous radioimmunoassay has been developed using the avian growth hormone.

1982 ◽  
Vol 63 (s8) ◽  
pp. 179s-181s
Author(s):  
Tamiko Ohsawa ◽  
Shigehisa Hirose ◽  
Tadashi Inagami ◽  
Kazuo Murakami

1. Renin was purified to homogeneity from bovine anterior pituitary by using batchwise DEAE-cellulose chromatography, pepstatin-aminohexyl-agarose affinity chromatography, Ultrogel AcA 44 gel filtration and DEAE-Sephacel and CM-cellulose ion exchange chromatography. 2. The enzyme has a molecular weight of 36 000 and an isoelectric point of 5.25, and exhibits optimum activity at a pH between 6.5 and 7.5. 3. The amino acid composition and antigenic properties of this purified renin are very similar to those of rat, dog and hog kidney renins.


1972 ◽  
Vol 130 (1) ◽  
pp. 211-219 ◽  
Author(s):  
Colin H. Self ◽  
P. David J. Weitzman

Two isoenzymes of NADP-linked isocitrate dehydrogenase have been identified in Acinetobacter lwoffi and have been termed isoenzyme-I and isoenzyme-II. The isoenzymes may be separated by ion-exchange chromatography on DEAE-cellulose, by gel filtration on Sephadex G-200, or by zonal ultracentrifugation in a sucrose gradient. Low concentrations of glyoxylate or pyruvate effect considerable stimulation of the activity of isoenzyme-II. The isoenzymes also differ in pH-dependence of activity, kinetic parameters, stability to heat or urea and molecular size. Whereas isoenzyme-I resembles the NADP-linked isocitrate dehydrogenases from other organisms in having a molecular weight under 100000, isoenzyme-II is a much larger enzyme (molecular weight around 300000) resembling the NAD-linked isocitrate dehydrogenases of higher organisms.


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.


1973 ◽  
Vol 133 (3) ◽  
pp. 593-599 ◽  
Author(s):  
Sarah Bullock ◽  
Bryan Winchester

Three and four N-acetylhexosaminidase components, from ram testis and epididymis respectively, have been separated by ion-exchange chromatography on DEAE-cellulose. Although they all have the same molecular weight (approx. 140000) and very similar catalytic properties towards the synthetic substrates, 4-methylumbelliferyl N-acetyl-β-glucosaminide and N-acetyl-β-galactosaminide, isoelectric focusing of the individual components showed that each had a distinct pI value. Isoelectric focusing has also been used to demonstrate the occurrence of multiple forms in ejaculated ram semen.


1984 ◽  
Vol 62 (6) ◽  
pp. 449-455 ◽  
Author(s):  
Show-Jy Lau ◽  
Bibudhendra Sarkar

The binding of six trace metals, Mn(II), Ni(II), Zn(II), Cu(II), Cd(II) and Fe(III), to human cord serum has been studied by Sephadex G-100 gel filtration at physiological pH, using radioisotopes as tracers. The results are compared with those obtained from adult serum. In both cord and adult sera, extensive amounts of the metals are bound to high molecular weight proteins. Among them, Fe(III) is mostly bound to transferrin; Ni(II), Zn(II), Cu(II), and Cd(II) are bound to albumin and other macro-molecules. The binding of Mn(II) either to transferrin or albumin is not resolved. Small fractions of Zn(II), Cu(II), and Cd(II) and large fractions of Mn(II) and Ni(II) are found to be associated with low molecular weight components of both sera. The distribution varies from metal to metal. However, the low molecular weight component of the size 1500 – 10 000 is present in all the metals studied. Further purification of this component was attempted by DEAE-cellulose ion-exchange chromatography. The possible identity as well as the biological role played by this particular component of serum in the transport of metals in blood and across membranes is discussed.


1974 ◽  
Vol 52 (11) ◽  
pp. 1067-1072 ◽  
Author(s):  
P. Brazeau ◽  
W. Vale ◽  
R. Burgus ◽  
R. Guillemin

Isolation of somatostatin, a tetradecapeptide of ovine origin inhibiting somatotropin secretion, is reported. About 490 000 hypothalamic fragments were submitted to alcohol–chloroform extraction, countercurrent distribution, ion-exchange chromatography, gel filtration, and partition chromatography. Of the 8.5 mg material thus obtained, 77% was accounted for by a peptide shown homogeneous by electrophoresis, thin-layer chromatography, and amino acid analysis. The peptide inhibits the secretion of radioimmunoassayable growth hormone at doses of ≥ 1.0 nM in vitro and 400 ng per rate in vivo.


1971 ◽  
Vol 125 (4) ◽  
pp. 1075-1080 ◽  
Author(s):  
W. J. Broughton ◽  
M. J. Dilworth

1. The finding that the plant is the genetic determinant of leghaemoglobin production in legume nodules was further tested by inoculating snake beans with two strains of Rhizobium selected to give large genetic differences. Carbohydrate requirement patterns, immunological techniques and DNA base ratio determinations were used to demonstrate genetic differences between the two rhizobial strains. 2. Partially purified preparations of the haemoglobins from the nodules produced by the two strains showed no differences when examined by electrophoresis, isoelectric focusing or ion-exchange chromatography. 3. Two different leghaemoglobins from each type of nodule were separated by chromatography on DEAE-cellulose. One of these was isolated in the Fe3+ form and accounted for two-thirds of the total leghaemoglobin. When it was examined in the analytical ultracentrifuge and by amino acid analysis, this major component did not vary with the inoculant rhizobial strain. The molecule had an s20,w of 1.88S, a diffusion coefficient of 10.7×10-7cm2·s-1 and a mol. wt. of 16700. 4. These results strongly support the hypothesis that the mRNA for leghaemoglobin is transcribed from plant DNA.


2021 ◽  
Vol 83 (3) ◽  
pp. 72-80
Author(s):  
O.B. Balko ◽  

According to our previous results, S-type bacteriocins of Pseudomonas aeruginosa are characterized by high activity against phytopathogenic Pseudomonas syringae strains. In addition to these pyocins producing strains are able to synthesize microcin-II-like bacteriocins. Presence of interaction between these two killer factors can determine methods of their use and activity increase of bacteriocins with antiphytopathogenic properties. The aim of the work was to test possibility of interaction between S-type pyocins and microcin-II-like bacteriocins of P. aeruginosa. Methods. The objects of the study were pyocins produced by 6 P. aeruginosa strains. Killer factors in composition of induced lysates were concentrated by 70% ammonium sulphate precipitation, dialyzed through dialysis membrane with molecular weight cut-off (MWCO) 3.5 kDa. Then ion-exchange chromatography with DEAE-cellulose, gel filtration with Sephadex G-75 and ultracentrifugation at 215.000 g for 1 and 4 hours were used for their separation. Protein concentration and antimicrobial activity were determined in obtained fractions. Visualization of proteins in active fraction composition was conducted by electrophoresis according to the Laemmli method. Results. Under ion-exchange chromatography with DEAE-cellulose application elution of bacteriocins available in lysate composition occurs simultaneously. The highest indices of activity and protein concentration were in the 4th fraction, containing two protein bands with molecular weight near 58 and 9 kDa, which are typical for S5 pyocin and microcin-II-like bacteriocins of P. aeruginosa. Further gel filtration of sampled fractions through Sephadex G-75 allowed to separate noted killer factors and obtaine purified fraction containing microcin-II-like pyocins only. Application of ultracentrifugation during 1 hour didn’t precipitate studied bacteriocins, whereas during 4 hours – lead to their separation. At the same time a twofold increase of activity indices for S-type pyocins in precipitates and for microcin-IIlike killer factors – in supernatants were observed. However achieved concentration was characterized by short-term effect, since in 14 days activity of supernatants decreased by 4–16 times, and for precipitates – by 80–640 times. Then revealed tendency for activity decrease continued. Conclusions. S-type pyocins and microcin-II-like bacteriocins of P. aeruginosa interact with each other, that ensures their stabilization and protects again destruction. Application of methods that cause separation of these killer factors is inexpedient, since it results into considerable decrease of bacteriocin activity indices.


1973 ◽  
Vol 51 (1) ◽  
pp. 56-70 ◽  
Author(s):  
R. S. Hodges ◽  
L. B. Smillie

Previous studies have demonstrated that rabbit skeletal tropomyosin consists of two or more chemically non-identical but highly homologous polypeptide chains. Attempts by a variety of techniques to prepare pure tropomyosin chains in amounts adequate for chemical characterization have been unsuccessful to date. To provide more extensive information for the purpose of elucidating the relationship between amino acid sequence and the coiled-coil structure of tropomyosin, a cyanogen bromide treatment of the S-carboxymethylated protein was carried out. The fragments were separated into small and large components by gel filtration on Sephadex G-50. The small fragments were fractionated by ion-exchange chromatography and electrophoresis on paper and their sequences elucidated by conventional methods. Coupled with previous data, these results indicate a minimum of seven unique methionine sequences and are consistent with a high degree of homology in the tropomyosin polypeptide chains. From the mixture of the larger cyanogen bromide polypeptides, a fragment was isolated by ion-exchange chromatography on QAE-Sephadex. In aqueous buffer it had a molecular weight of 35 000 and an α-helical content of about 60% as estimated by circular dichroism. In 8 M urea its molecular weight was reduced to 15 000, a value in reasonable agreement with a minimal molecular weight of 17 000 calculated from its amino acid composition. From its histidine content (two residues) and the known COOH-terminal amino acid sequence of the protein, the fragment was concluded to be derived from the COOH-terminal half of the molecule. These results are consistent with a degree of 'coiled-coil' structure in a fragment representing about one-half of the tropomyosin molecule.


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