The Separation of two Deoxyribonucleases from Extracts of Intestinal Mucosa of the Rat

1972 ◽  
Vol 50 (6) ◽  
pp. 697-703 ◽  
Author(s):  
C. Y. Lee ◽  
Sheilia Lawrence ◽  
S. H. Zbarsky

Two deoxyribonucleases have been demonstrated in cell-free extracts of rat intestinal mucosa. The enzymes were separated by ion-exchange chromatography on DEAE-cellulose and further purified by partition on hydroxyapatite. One DNase had optimum activity at pH 6.8–7.0 in ammonium acetate buffer, required Mn2+ or Mg2+ for activity, and was inhibited by EDTA. This enzyme is a DNase I by Laskowski's criteria Advan. Enzymol. 29, 165 (1967). The second enzyme was a DNase II with optimum activity at pH 3.5–4.0 in sodium formate buffer, was not inhibited by EDTA, and showed no requirement for divalent cations. Both enzymes were active only with native DNA and had no action on heated DNA or purified yeast transfer RNA.

1980 ◽  
Vol 58 (9) ◽  
pp. 749-753 ◽  
Author(s):  
D. Stephen Keys ◽  
S. H. Zbarsky

Mucosa from bovine small intestine was homogenized in Krebs–Ringer phosphate buffer, pH 7.8, the homogenate centrifuged at 16 300 × g, and the supernatant solution filtered through cheesecloth to remove lipid material. The filtrate was centrifuged at 105 000 × g and the supernatant solution chromatographed on DEAE-cellulose. The major peak of DNase II activity, eluted with 20 mM phosphate – 10 mM EDTA buffer, pH 7.8, was purified further by ion-exchange chromatography on CM-cellulose and gel filtration on Sephadex G-100. The enzyme was purified 78-fold in 13% yield. Evidence was adduced to indicate that the second minor peak of DNase II activity, eluted from the DEAE-cellulose by a potassium chloride gradient in the 20 mM phosphate – 10 mM EDTA buffer, was an artifact arising from the presence of significant amounts of DNA in the 105 000 × g supernatant. The enzyme degraded DNA endonucleolytically to 3′-PO4, 5′-OH oligonucleotides and is similar in its properties to DNase II from other tissues.


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.


1964 ◽  
Vol 29 (1) ◽  
pp. 61-69 ◽  
Author(s):  
ANNE STOCKELL HARTREE ◽  
W. R. BUTT ◽  
K. E. KIRKHAM

SUMMARY Ion-exchange chromatography was used to further purify a human pituitary fraction rich in thyrotrophic and luteinizing hormone activities. Approximately twofold concentration of both activities was obtained by chromatography on IRC-50 at pH 7·5, but the hormones were not separated. Subsequent chromatography on DEAE-cellulose at pH 9·5 led to a tenfold concentration of the luteinizing hormone in a fraction practically free of thyrotrophic activity and to a fourfold concentration of the thyrotrophic hormone in a fraction still exhibiting substantial luteinizing hormone activity.


1989 ◽  
Vol 44 (6) ◽  
pp. 619-626 ◽  
Author(s):  
P. Erlhöfer ◽  
W. Preetz

All components of the two series Cs2[PtF„35Cl6-n] and Cs2[PtFn37Cl6-n], including the pairs of geometric isomers for n = 2,3, 4, have been prepared and isolated by ion exchange chromatography on DEAE cellulose. The highly resolved low temperature (80 K) IR and Raman spectra of the pure isotopomers show distinctive isotopic shifts for different vibrational modes up to 10 cm-1. The excellent agreement of the observed values with Teller-Redlich calculations verifies the assignment of all stretching and especially of the narrow deformation bands. For transcomplexes containing 35Cl-Pt-37Cl axes, the lowered symmetry affects the restriction of the rule of mutual exclusion


1975 ◽  
Vol 147 (1) ◽  
pp. 45-53 ◽  
Author(s):  
R Davidson ◽  
A Gertler ◽  
T Hofmann

An acid proteinase from Aspergillus oryzae was isolated from a commercial powder by successive (NH4)2SO4 fractionation, acetone precipitation, and ion-exchange chromatography on phosphate- and DEAE-cellulose columns. The purified enzyme was found to be homogeneous by ultracentrifuge-sedimentation analysis (S20, W equal 3.63S), but electrofocusing in polyacrylamide gels and electrophoresis at pH 3.2 revealed that it consists of two very closely migrating bands. No difference in the amino acid composition and enzymic activities of the two partially separated bands could be detected, and it was concluded that the acid proteinase exists in two molecular forms. The enzyme activates bovine trypsinogen and chymotrypsinogen at pH 3.5 (the kappacat. and Km values at 35degrees C are 11.3S- minus 1, 0.10mM and 1.14S- minus 1, 0.18mM respectively). It hydrolyses the Phe-Phe bond of the synthetic pepsin substrates Z-His-Phe-Phe-OEt (kappacat. equal 1.65S- minus 1, Km equal 0.640mM at pH 3.5, 30degrees C) and Z-Ala-Ala-Phe-Phe-OPy4Pr (kappacat. equal 0.37S- minus 1, Km equal 0.037 mM at pH2.9, 39degrees C), where Z represents benzyloxycarbonyl and OPy4Pr represents 3-(4-pyridyl)-propyl 1-ester. Activation of bovine chymotrypsinogen results from the cleavage of the Arg(15)-Ile(16) bond in the zymogen. No other cleavages were observed. The use of A. oryzae proteinase provides a simple tool for the production of pi-chymotrypsin in good yield and purity.


1998 ◽  
Vol 53 (8) ◽  
pp. 816-818 ◽  
Author(s):  
W. Preetz ◽  
S. Zander ◽  
C. Bruhn

Abstract By reaction of [B6H6]2-with (SCN)2 in dichloromethane at -80 C° the thiocyanatohexaborate anion is formed and can be isolated by ion exchange chromatography on diethylaminoethyl (DEAE) cellulose. The X-ray structure determination of Cs2[B6H5(SCN)] (orthorhombic, space group Pbca with a = 9.506(5), b = 10.644(5), c = 21.857(5) Å, Z = 8) reveals that the SCN substituent is bonded via the S atom with the B-S distance of 1.885(9) Å and the B-S-C angle of 99.8(5)°. The SCN group is nearly linear (179.9(9)°).


2000 ◽  
Vol 55 (11) ◽  
pp. 1031-1036
Author(s):  
S. Zander ◽  
W. Preetz

The first aryl derivatives of c/oso-hexahydrohexaborate are formed by reaction of [B6H6]2- with 1-bromo-4-nitrobenzene and 2-bromo-5-nitrotoluene in acetonitrile at 80 °C. Cs2[B6H5- (1,4-C6H4(NO2))] and Cs2[B6H5(C6H3-1-(CH3)-5-(NO2))] can be isolated by ion exchange chromatography on diethylaminoethyl (DEAE) cellulose. Further treatment with /V-chlorosuccinimide yields the perhalogenated derivative (CH2Py2)[B6Cl5(1,4-Ph(NO2))]CH3CN which has been characterized by X-ray diffraction analysis (orthorhombic, space group P2( 2,2t, a = 9.810(4), b - 14.412(3), c - 18.586(9) A, Z = 4). The 11B NMR spectra of all compounds are consistent with a monosubstituted B6-cluster. The IR and Raman spectra exhibit characteristic BB, BH, CH, CC and NO vibrations, respectively.


1976 ◽  
Vol 157 (2) ◽  
pp. 301-306 ◽  
Author(s):  
J Travis ◽  
J Bowen ◽  
D Tewksbury ◽  
D Johnson ◽  
R Pannell

The dye Cibacron Blue F-3-GA was conjugated to Sepharose to provide an affinity column for serum albumin. Passage of whole human plasma through a column of Cibacron Blue-Sepharose results in the removal of approx. 98% of the albumin. The latter can be quantitatively recovered by desorption with NaSCN. Albumin-depleted plasma can be readily resolved into discrete fractions by a combination of conventional biochemical techniques. In particular, the resolution of plasma proteins with properties similar to those of native human plasma albumin can readily be accomplished by ion-exchange chromatography of the Sepharose-dye-treated plasma on DEAE-cellulose.


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