Uranic Acid Research Articles

Polygalacturonic Acid Metabolism in Bacteria: I. ENZYMATIC FORMATION OF 4-DEOXY-l-THREO-5-HEXOSEULOSE URONIC ACID

SUMMARY A new intermediate in the bacterial metabolism of polygalac- turonic acid, 3-deoxy-n-glycero-2,5-hexodiulosonic acid, has been POLYGALACTURONATE MUCIC NAD / ACID c-- DCALACTURONATE COMPOUND I it It D-T-AGATURONATE COhiPbUND II II NADH D-ALTRONATE H20 It - ZKETO-SDEOXY- D-GLUCONATE 1 ATP 2-KEfO-3-DEOXY- 6-PHOSPHO-D- GLUCONATE 21. DELEY, J., AND DOUDOROFF, M., J. Biol. Chem., 227, 745 (1957). 22. PALLERONI, N. J., AND DOUDOROFF, M., J. Biol. Chem., 223, It 499 (1956). PYRUVATE TRIO;E PHOSPHATE FIG. 8. Outline of polygalacturonate catabolism by extracts of an adapted pseudomonad. 25. LINKER, A., HOFFMAN, P., MEYER, K., SAMPSON, P., AND KORN, E. D., J. Biol. Chem., 235, 3061 (1960). 23. WEIMBERG, R., J. Biol. Chem., 234, 727 (1959). 24. MERRICK, J. M., AND ROSEMAN, S., J. Biol. Chem., 236, 1274 (1960). isolated and characterized. This compound has been shown to arise by the isomerization of 4-deoxy-L-threo-5-hexoseulose uranic acid and be converted 2-deoxy-3-keto-n-gluconic by a specific pyridine-linked dehydrogenase. The isomerase and the dehydrogenase enzymes responsible for this interconversion have been prepared in partially purified form, and a study of their properties has been undertaken. n-Galacturonic acid, the alternate monosaccharide end product of polygalacturonate metabolism, has been shown to be readily converted to n-tagaturonic, n-altronic, and 2-keto-3-deoxy-n- gluconic acids by extracts of the adapted pseudomonad employed in these studies. REFERENCES 1.

The chemistry of uranyl nitrate-hydroxide-urea systems

The reaction mechanism has been determined for addition of ammonium hydroxide or sodium hydroxide to a solution of uranyl nitrate and urea. Evidence has been presented to show that nitrouranic acid [UO 2(NO 3)OH] and hydrated uranic acid (H 2UO 4·H 2O) are intermediate compounds. Finally, a discussion of the relationship of these intermediates to the chemistry of uranates is presented.

Some evidence for the presence of uranic acid in uranium trioxide-water systems

The hydrates, UO 3·2H 2O, UO 3·0·8H 2O and UO 3·0·5H 2O described by Dawson et al. (1) were shown to react with the organic base, urea, to form urea uranate H 2UO 4·2CO(NH 2) 2. The formation of this salt provides evidence that these “hydrates” constitute a series of acids whose relationship may be expressed as follows: ▪ (pyrouranic acid). Attempts to characterize the “hydrate” UO 3·0·8H 2O were unsuccessful; instead the presence of a mixture of H 2UO 4 and H 2U 2O 7 was indicated.

THE ISOLATION OF THE NON-SPECIFIC HYALURONIDASE INHIBITOR OF HUMAN BLOOD

SUMMARY A homogeneous substance has been isolated from blood which inhibits bovine testicular hyaluronidase. It has been found to contain amino acids and hexosamine and gives the carbazole color reaction for uranic acid. It contains less than 0.1 per cent sulfur as sulfate, less than 0.2 per cent phosphorus, and less than 5 per cent lipides. No evidence for the presence of heparin was found. The molecular weight was estimated at 100,000, the mobility in Verona1 buffer at pH 8.6, p = 0.1, was -5.4 X 10-S sq. cm. per second per volt, the sedimentation constant was .so,~ = 3.75, and the diffusion constant was DZo = 3.4 f 0.3 x 10-’ sq. cm. per second. BIBLIOGRAPHY 1. Dorfman, A., Ann. New York Acad. SC., 62, 1098 (1950). 2. Glick, D., J. Mt. Sinai Hosp., 17. 207 (1950). 3. Mathews, M. B., and Dorfman, A., Physiol. Rev., in press. 4. Dorfman, A., Ott, M. L., and Whitney, R., J. Biol. Chem., 174, 621 (1948). 5. Glick, D., and Moore, D. H., Arch. Biochem., 19, 173 (1948). 1 The authors are indebted to Dr. Carol Spurling for aid in these studies. by guest, on July 20, 2011www.jbc.orgDownloaded from

Advantages of Uranium Fixation in Modern Cytological Technique

AN attempt to use uranium as a fixing agent was apparently made as early as 1882 when Schenk1 noticed that uranium acetate had a mild fixing action and a high degree of penetration. The nitrate and acetate have since been used for special purposes by Cajal2, Nebel3 and others. Uranic acid as a substitute for osmic acid was introduced in this laboratory some years ago. Catcheside4, who kindly carried out a number of tests with this reagent, finally came to the conclusion that, although good fixation could be obtained, the effects were rather erratic, and La Cour5 later confirmed the views expressed by Catcheside. Semmens6 first gave a systematic account of the value of uranium as a substitute for osmium in fixatives employed for plant cytology; he also indicated the theoretical grounds for the use of this metal. In a later paper7 he further pointed out that the erratic fixation previously recorded appeared to be due to the variable composition of the so-called uranic acid of commerce. To overcome this difficulty he proposed the use of sodium diuranate (Na2U2O7), a compound that is much easier to standardize.