scholarly journals Methylated purines in the deoxyribonucleic acid of various Syrian-golden-hamster tissues after administration of a hepatocarcinogenic dose of dimethylnitrosamine

1976 ◽  
Vol 157 (3) ◽  
pp. 627-634 ◽  
Author(s):  
G P Margison ◽  
J M Margison ◽  
R Montesano
Keyword(s):  
Acid Hydrolysis ◽  
Golden Hamster ◽  
Deoxyribonucleic Acid ◽  
Syrian Golden Hamster ◽  
Mild Acid Hydrolysis ◽  
Liver Tumours ◽  
Purine Bases ◽  
Syrian Golden Hamsters ◽  
Mild Acid ◽  
Lung And Kidney

1. DNA was extracted from livers, kidneys and lungs of Syrian golden hamsters at various times (up to 96h) after injection of a hepatocarcinogenic dose of [14C]dimethylnitrosamine. Purine bases were released from the DNA by mild acid hydrolysis and separated by Sephadex G-10 chromatography. 2. At 7h after dimethylnitrosamine administration liver DNA was alkylated to the greatest extent, followed by that of lung and kidney, the values for which were 8 and 3% respectively of those for liver. 3. The O6-methylguanine/7-methylguanine ratios were initially the same in all three organs and in the liver DNA of rats under similar conditions of dose. 4. O6-Methylguanine was the most persistent alkylated purine in all three hamster tissues. There was evidence for excision of 7-methyl-guanine, the highest activity for this being present in the liver. 5. Detectable amounts of the minor products 3-methyladenine, 1-methyladenine, 3-methylguanine and 7-methyladenine were present in most hamster tissues, and their individual rates of loss from liver DNA were determined. 6. Ring-labelling of the normal purines in DNA was highest in the liver, followed closely by the lung (80% of that in liver) whereas the kidney had very low incorporation (3% of that in liver). 7. The results are discussed with respect to the hepatotoxicity of dimethylnitrosamine, the miscoding potential of the various alkylation products and the induction of liver tumours in hamsters.

scholarly journals Evidence for the binding of the carcinogen 3-methylcholanthrene to both the purine and the pyrimidine bases of hamster fibroblast deoxyribonucleic acid (Short Communication)

1973 ◽  
Vol 135 (2) ◽  
pp. 375-378 ◽  
Author(s):  
Peter A. Jones ◽  
Wieland Gevers ◽  
Arthur O. Hawtrey
Keyword(s):  
Acid Hydrolysis ◽  
Deoxyribonucleic Acid ◽  
Short Communication ◽  
Dna Degradation ◽  
Mild Acid Hydrolysis ◽  
Chemical Methods ◽  
Purine Bases ◽  
Pyrimidine Bases ◽  
Mild Acid

The binding of [3H]3-methylcholanthrene to the DNA of hamster fibroblasts was studied by using chemical methods for DNA degradation. DNA depurinated by mild acid hydrolysis released approximately half of the radioactivity at the same rate as the purine bases, but the resulting apurinic acid still contained radioactive carcinogen.

THE REACTION OF MUSTARD GAS WITH DEOXYRIBONUCLEIC ACID WITH SPECIAL REFERENCE TO THE PYRIMIDINES

1961 ◽  
Vol 39 (10) ◽  
pp. 1493-1499 ◽  
Author(s):  
I. G. Walker ◽  
W. J. Watson
Keyword(s):  
Special Reference ◽  
Acid Hydrolysis ◽  
Perchloric Acid ◽  
Deoxyribonucleic Acid ◽  
Hydrogen Ion ◽  
Mustard Gas ◽  
Mild Acid Hydrolysis ◽  
Phosphoryl Groups ◽  
Hydrolysis Of ◽  
Mild Acid

Mustard gas was allowed to react with DNA at pH 7.4. After mild acid hydrolysis of the product, the mustard (estimated as sulphur) was found in three fractions: bound to purine, bound to apurinic acid, and a portion bound to neither and whose origin was not apparent. The apurinic acid was degraded to free pyrimidines by perchloric acid hydrolysis. From the hydrolyzate, a cytosine and a thymine derivative were isolated and characterized spectrophotometrically. Protamine titration of the DNA–mustard gas product indicated that primary phosphoryl groups had been esterified. It is difficult to reconcile this conclusion with a previous finding that phosphate esterification did not occur. The latter result was obtained by measuring the release of hydrogen ion during reaction.

scholarly journals Accumulation of O6-methylguanine in non-target-tissue deoxyribonucleic acid during chronic administration of dimethylnitrosamine

1977 ◽  
Vol 165 (3) ◽  
pp. 463-468 ◽  
Author(s):  
G P Margison ◽  
J M Margison ◽  
R Montesano
Keyword(s):  
Dna Repair ◽  
Dna Synthesis ◽  
Acid Hydrolysis ◽  
Deoxyribonucleic Acid ◽  
Chronic Administration ◽  
The Other ◽  
Target Tissue ◽  
Mild Acid Hydrolysis ◽  
Stomach Tube ◽  
Mild Acid

1. BD-IV rats were given labelled dimethylnitrosamine (2 mg/kg) by stomach tube on weekdays (Monday to Friday) for up to 24 weeks. The rats killed after 2, 4, 8, 16 and 24 weeks of treatment (72 h after the final dimethylnitrosamine gavage) and DNA was isolated from the pooled livers, kidneys and lungs. Purine bases were released from the DNA by mild acid hydrolysis and separated by Sephadex G-10 chromatography. 2. Throughout the experiment, the content of 7-methylguanine in liver DNA was approx. 16 times that in kidney and lung. The amount of this product increased in the DNA of all three tissues up to 16 weeks, but by 24 weeks had decreased by 20% in the liver and 46% in the other tissues. 3. O6-Methylguanine was not detected in liver DNA, but was easily measured in kidney and lung DNA after 4 weeks of dimethylnitrosamine administration. The amount of O6-methylguanine in kidney and lung DNA increased relative to that of 7-methylguanine, and by 24 weeks was 60% of the 7-methylguanine content in both tissues. 4. Incorporation of radioactive C1 breakdown products of dimethylnitrosamine into normal purines in DNA increased continuously in all three tissues. 5. The results are discussed with respect to the specific hepatocarcinogenic effect of chronic administration of dimethylnitrosamine and the possible contribution of increased DNA repair and DNA synthesis.

Amino acid sequence of cyanogen bromide fragment CB5 of human hemopexin

1989 ◽  
Vol 54 (3) ◽  
pp. 803-810 ◽  
Author(s):  
Ivan Kluh ◽  
Ladislav Morávek ◽  
Manfred Pavlík
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Acid Hydrolysis ◽  
Cyanogen Bromide ◽  
Polypeptide Chain ◽  
Amino Acid Residues ◽  
Mild Acid Hydrolysis ◽  
Methionine Residue ◽  
Cyanogen Bromide Fragment ◽  
Mild Acid

Cyanogen bromide fragment CB5 represents the region of the polypeptide chain of hemopexin between the fourth and fifth methionine residue (residues 232-352). It contains 120 amino acid residues in the following sequence: Arg-Cys-Ser-Pro-His-Leu-Val-Leu-Ser-Ala-Leu-Thr-Ser-Asp-Asn-His-Gly-Ala-Thr-Tyr-Ala-Phe-Ser-Gly-Thr-His-Tyr-Trp-Arg-Leu-Asp-Thr-Ser-Arg-Asp-Gly-Trp-His-Ser-Trp-Pro-Ile-Ala-His-Gln-Trp-Pro-Gln-Gly-Pro-Ser-Ala-Val-Asp-Ala-Ala-Phe-Ser-Trp-Glu-Glu-Lys-Leu-Tyr-Leu-Val-Gln-Gly-Thr-Gln-Val-Tyr-Val-Phe-Leu-Thr-Lys-Gly-Gly-Tyr-Thr-Leu-Val-Ser-Gly-Tyr-Pro-Lys-Arg-Leu-Glu-Lys-Glu-Val-Gly-Thr-Pro-His-Gly-Ile-Ile-Leu-Asp-Ser-Val-Asp-Ala-Ala-Phe-Ile-Cys-Pro-Gly-Ser-Ser-Arg-Leu-His-Ile-Met. The sequence was derived from the data on peptides prepared by cleavage of fragment CB5 by mild acid hydrolysis, by trypsin and chymotrypsin.

scholarly journals Presence of 3-O-methyl-l-xylose in the lipopolysaccharide of Pseudomonas maltophilia N.C.T.C. 10257

1977 ◽  
Vol 163 (1) ◽  
pp. 173-175 ◽  
Author(s):  
F Brown ◽  
D J Neal ◽  
S G Wilkinson
Keyword(s):  
Acid Hydrolysis ◽  
Mild Acid Hydrolysis ◽  
Whole Cells ◽  
Pseudomonas Maltophilia ◽  
Mild Acid

3-O-Methyl-L-xylose was isolated from whole cells of Pseudomonas maltophilia N.C.T.C. 10257. The sugar is a component of lipopolysaccharide from which a polysaccharide also containing L-rhamnose and L-xylose was released by mild acid hydrolysis. 3-O-Methyl-L-xylose was absent from five other strains of Ps. maltophilia and one strain of Pseudomonas geniculata.

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