scholarly journals ISOLATION AND CHARACTERIZATION OF CHROMATIN FROM NEUROSPORA CRASSA

1969 ◽  
Vol 43 (1) ◽  
pp. 51-58 ◽  
Author(s):  
R. S. Dwivedi ◽  
S. K. Dutta ◽  
D. P. Bloch
Keyword(s):  
Amino Acid ◽  
Neurospora Crassa ◽  
Polyacrylamide Gel Electrophoresis ◽  
Average Diameter ◽  
Uv Absorption ◽  
Eosin Y ◽  
Basic Proteins ◽  
Isolation And Characterization ◽  
Calf Thymus

Different preparations of chromatin isolated from mycelia of Neurospora crassa were analyzed for DNA-associated RNA and proteins. The UV absorption spectra, the ultrastructure of chromatin, and the amino acid composition of the acid-extractable proteins were studied. The protein:DNA ratios range from 1.5 to 2.8; the RNA:DNA ratios range from 0.5 to 1.24. UV absorption shows a macimum at 259 mµ and a minimum at 238–239 mµ. The E280/E260 ranges from 0.59 to 0.70. Electron microscopy reveals a fibrous structure with individual fibers of 120–150 A average diameter. Attempts were made to study the protein by polyacrylamide gel electrophoresis and amino acid analysis. The results indicate that Neurospora chromatin does not contain basic proteins comparable to calf thymus histone. The ratios of basic to acidic amino acids range from 0.93 to 1.19. On electrophoresis, no bands are seen whose positions correspond to those of histones. Staining for basic proteins with fast green or eosin Y at pH 8.2 also shows a negative reaction, suggesting the absence of histones.

Isolation and characterization of a mitochondrial D-amino acid oxidase from Neurospora crassa

1977 ◽  
Vol 55 (1) ◽  
pp. 66-74 ◽  
Author(s):  
Melvin G. Rosenfeld ◽  
Edward H. Leiter
Keyword(s):  
Amino Acid ◽  
Neurospora Crassa ◽  
Mitochondrial Fraction ◽  
Acid Oxidation ◽  
Gel Chromatography ◽  
Acid Oxidase ◽  
Amino Acid Oxidase ◽  
Ph Optimum ◽  
Isolation And Characterization

D-Amino acid oxidase (EC 1.4.3.3) activity in homogenates of Neurospora crassa strain SY7A was found to sediment with the mitochondrial fraction. Digitonin fractionation studies on purified mitochondria have indicated a matrix localization of the enzyme. Additionally, a peroxidase (EC 1.11.1.7) activity, which may remove hydrogen peroxide formed as a product of D-amino acid oxidation, was also found in the mitochondrial matrix.Partial purification (20- to 30-fold) of the mitochondrial D-amino acid oxidase was achieved. The enzyme exhibited a pH optimum between 9.0 and 9.2, temperature optimum between 20 and 30 °C, and a molecular weight of 118 000 ± 6000 as determined by gel electrophoresis and 125 000 as determined by gel chromatography.

scholarly journals The isolation and characterization of corticotropin from the pituitary gland of the ostrich Struthio camelus

1977 ◽  
Vol 165 (3) ◽  
pp. 519-523 ◽  
Author(s):  
R J Naudé ◽  
W Oelofsen
Keyword(s):  
Amino Acid ◽  
Polyacrylamide Gel Electrophoresis ◽  
Amino Acid Residues ◽  
Struthio Camelus ◽  
Isolation And Characterization ◽  
Isoelectric Points ◽  
Pituitary Glands ◽  
Amide Content

1. Avian corticotropin (ACTH) was purified from both fresh and aged pituitary glands of the ostrich Struthio camelus. 2. The isolation of corticotropin in pure form involved acid/acetone extraction, NaCl fractionation, CM-cellulose chromatography and Sephadex G-50 chromatography. 3. The hormone preparations from fresh and aged glands behaved as single substances on polyacrylamide-gel electrophoresis, and both preparations were found to consist of 39 amino acid residues, in identical molar proportions for the different amino acids. 4. The isoelectric points of the two hormone preparations were estimated to be in the range pH 8.3-8.7, indicating possible differences in amide content, and the N-terminal amino acid of both preparations appeared to be serine. 5. The hormone preparations from fresh and aged glands exhibited similar biological potencies (73 and 77 i.u./mg respectively), as measured by steroidogenesis in vitro. 6. Apart from possible differences in amide content, the corticotropin preparations obtained from fresh and aged glands appear to be indistinguishable.

Isolation and characterization of histones and other acid-soluble chromosomal proteins from Physarum polycephalum

1982 ◽  
Vol 60 (3) ◽  
pp. 263-271 ◽  
Author(s):  
Serge Côté ◽  
Paul Nadeau ◽  
James M. Neelin ◽  
Dominick Pallotta
Keyword(s):  
Amino Acid ◽  
Physarum Polycephalum ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
High Mobility ◽  
Apparent Molecular Weight ◽  
Chromosomal Protein ◽  
Basic Proteins ◽  
Isolation And Characterization ◽  
Core Histones

Chromosomal basic proteins were isolated from amoebal and plasmodial stages of the acellular slime mold Physarum polycephalum. Polyacrylamide electrophoresis on high resolution acid–urea gels separated the five histone fractions in the sequence H1, H2A, H2B, H3, andH4. Under these electrophoretic conditions Physarum histones migrated more like plant (rye) than animal (calf) histones. Furthermore, Physarum histones H1, H2A, and H2B have higher molecular weights on sodium dodecyl sulfate (SDS) gels than the corresponding calf fractions. No differences were detected between amoebal and plasmodial histones on either acid–urea or SDS–polyacrylamide gel electrophoresis. Amoebal basic proteins were fractionated by exclusion chromatography. The five histone fractions plus another major acid-soluble chromosomal protein (AS) were isolated. The Physarum core histones had amino acid compositions more closely resembling those of the calf core histones than of rye, yeast, or Dictyostelium. Although generally similar in composition to the plant and animal H1 histones, the Physarum H1 had a lower lysine content. The AS protein was extracted with 5% perchloric acid or 0.5 M NaCl, migrated between histones H3 and H4 on acid–urea polyacrylamide gels, and had an apparent molecular weight of 15 900 on SDS gels. It may be related to a protein migrating near H1. Both somewhat resembled the high mobility group proteins in amino acid composition.

PURIFICATION AND PARTIAL CHEMICAL CHARACTERIZATION OF SHEEP NEUROPHYSIN

1973 ◽  
Vol 74 (2) ◽  
pp. 226-236 ◽  
Author(s):  
Michel Chrétien ◽  
Claude Gilardeau
Keyword(s):  
Amino Acid ◽  
Polyacrylamide Gel Electrophoresis ◽  
Chemical Characterization ◽  
Terminal Amino Acid ◽  
Amino Acid Determination ◽  
Pituitary Glands ◽  
Terminal Amino ◽  
Partial Chemical ◽  
Acid Determination

ABSTRACT A protein isolated from ovine pituitary glands has been purified, and its homogeneity assessed by NH2- and COOH-terminal amino acid determination, ultracentrifugation studies, and polyacrylamide gel electrophoresis after carboxymethylation. Its chemical and immunochemical properties are closely similar to those of beef and pork neurophysins, less similar to those of human neurophysins. It contains no tryptophan (like other neurophysins) or histidine (like all except bovine neurophysin-I and human neurophysins). It has alanine at the NH2-terminus and valine at the COOH-terminus. Its amino acid composition is similar to, but not identical with those of porcine and bovine neurophysins.

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