Different Chromatographic Forms of Neurospora crassa Nucleases Specific for Single-Stranded Nucleic Acids

1973 ◽  
Vol 51 (6) ◽  
pp. 888-895 ◽  
Author(s):  
Cecily Mills ◽  
M. J. Fraser

Three fractions with single-strand-specific nuclease activity have been isolated by chromatography on phosphocellulose and hydroxyapatite from Neurospora crassa conidia. Two of the fractions containing, respectively, 9% and 7% of the total nuclease activity recovered had the same chromatographic and enzymological properties as the endonuclease and exonuclease previously reported. The third fraction, containing 84% of the total nuclease activity recovered, was shown to contain a mixture of single-strand-specific endonuclease and exonuclease activities enzymologically indistinguishable from the activities previously described. The two components of this fraction were resolved by polyacrylamide gel electrophoresis. A fraction with the same chromatographic properties was also isolated from N. crassa mycelia in which single-strand-specific endonuclease, but no exonuclease activity, was detected. The two mycelial endonuclease fractions were enzymologically indistinguishable. The results were shown not to be due to artifacts of chromatography. Different batches of N. crassa conidia have been found to be heterogeneous with respect to contents of endonuclease and exonuclease.

1995 ◽  
Vol 16 (1) ◽  
pp. 903-904 ◽  
Author(s):  
Friederike Hilbert ◽  
Burkhard Mayr ◽  
Fritz Lackner ◽  
Friedrich Bauer

1978 ◽  
Vol 169 (2) ◽  
pp. 441-444 ◽  
Author(s):  
J Lumsden ◽  
J R Coggins

Evidence was obtained, from polyacrylamide-gel electrophoresis in the presence of urea and from peptide ‘mapping’ of specifically labelled cysteine-and methionine-containing peptides, that the two subunits of the arom multienzyme complex of Neurospora crassa are chemically very similar and possibly identical.


1986 ◽  
Vol 233 (3) ◽  
pp. 819-825 ◽  
Author(s):  
J Janatova

Disulphide bonds contribute significantly to the maintenance of structural/functional integrity of many proteins. Therefore it was of interest to study the distribution and the effect of disulphides on conformation of complement components C3 and C4. These proteins are precursors of several fragments with various binding sites and distinct physiological functions. The constituents of C3c (beta, alpha 27, alpha 43) and those of C4c (beta, alpha 27, alpha 16, gamma) were investigated, since other fragments of C3 or C4 do not participate in interchain linkages. Inter-and intra-chain disulphide bonds in C3c and C4c were localized by using a modification of conventional SDS (sodium dodecyl sulphate)/polyacrylamide-gel electrophoresis such that the change in mobility of disulphide-bond-containing proteins can be detected throughout the transition from a non-reduced to a fully reduced state. Several forms of the alpha 43 fragment from C3, and of the gamma-chain of C4, with different mobilities can exist, depending on the number of intra-chain disulphide bonds reduced. The intermediates (heterodimers) generated by a partial reduction of C3c or C4c were characterized by two-dimensional SDS/polyacrylamide-gel electrophoresis performed in the absence, then in the presence, of beta-mercaptoethanol. The inter-chain linkages in C3c were determined to be beta-alpha 27 and alpha 27- alpha 43, thus indicating the presence of only one interchain bond in C3. The two interchain bonds in C4c are beta-alpha 27 and alpha 16-gamma. The third interchain bond in C4 (alpha 27-gamma, tentative) remains to be determined.


2018 ◽  
Author(s):  
Emerald R. Tayor ◽  
Silvia Cavuoto ◽  
David M. Beal ◽  
Sophie Caujolle ◽  
Adrian Podoleanu ◽  
...  

<p>The prevalence, distinctive reactivity, and biological significance of sulphur-based groups in proteins and nucleic acids means that analysis of sulphur is of prime importance in biochemistry, biotechnology, and medicine. We report steps in the development of a method to detect these moieties using gold nanoparticles as adjuncts in polyacrylamide gel electrophoresis (Gold-PAGE).<b></b></p>


1981 ◽  
Vol 197 (2) ◽  
pp. 427-436 ◽  
Author(s):  
G A Nimmo ◽  
J R Coggins

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.


1983 ◽  
Vol 213 (2) ◽  
pp. 405-415 ◽  
Author(s):  
D D S Smith ◽  
J R Coggins

Limited proteolysis of the arom enzyme complex of Neurospora crassa by trypsin or subtilisin yielded a stable fragment of Mr 68000. This fragment, which was purified by two-dimensional polyacrylamide-gel electrophoresis, was shown by activity staining to contain the shikimate dehydrogenase active site, and by substrate labelling with 3-dehydroquinate and NaB3H4 to contain the 3-dehydroquinase active site. The fragment thus constitutes a bifunctional domain containing the two enzymic activities that are known, from genetic evidence, to be located adjacently at the C-terminal end of the pentafunctional arom polypeptide.


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