Showing papers in "Biochemical Journal in 1949"

Improved separation of sugars on the paper partition chromatogram.

Abstract: 450-5 m,u.)since it yielded a singleband on mixed chromatography with cryptoxanthin obtained from yellow maize (Sadana, 1946). Zone II. This was an orange-coloured band. The pigment was identified as neo-,-carotene U (maxima in light petroleum 480 and 450 mp.; Sadana, 1949). Zone III. This was reddish orange in colour. The pigment was extracted and identified as $-carotene by its absorption spectrum (maxima in light petroleum 482 and 452 mp) Zone IV. This was a brownish yellow band. The pigment was extracted and identified as neo-,B-carotene B (maxima in petroleum 470 and 443 m,u.). It yielded a single band on mixed chromatography with neo-,B-carotene B prepared by HCI treatment of ,-carotene (Sadana, 1949). Results of analyses of six varieties of loquats varying in colour from pale yellow to deep orange are shown in Table 1.

Properties of the acid phosphatases of erythrocytes and of the human prostate gland.

Abstract: There is much evidence indicating the non-identity of acid phosphatases of different origin. Davies (1934) has shown that the acid phosphatase of the red cell differs from that of spleen in that the former hydrolyses x-glycerophosphate much more readily than the ,-compound, while with the spleen enzyme ,-glycerophosphate is hydrolysed more quickly. Kutscher & Worner (1936) described the irreversible inactivation of the prostatic acid phosphatase by certain narcotics, including alcohols. This was used by Herbert (1944, 1945, 1946) for the identification and determination of the prostatic enzyme in blood serum, whose normal acid phosphatase is hardly affected by ethanol treatment. King, Wood & Delory (1945), on the other hand, found the acid phosphatases of prostate and red cells to be similar in many respects, including easy destruction by ethanol, but formaldehyde and L-tartrate (AbulFadl & King, 1947, 1948a, b) sharply distinguish the two enzymes by complete inactivation of the one or the other. In the present investigation the question of the identity of these two acid phosphatases is further dealt with. For this purpose, the rates of hydrolysis of phenyl phosphate by each enzyme at different pH values were determined, together with the relative rates of hydrolysis of aand P-glycerophosphates. This was followed by studies of the effects oforganic and inorganic substances belonging to different groups of a possible activating or inhibiting nature. The nature of the enzymes is discussed in the light of these experiments.

The measurement of the cytochrome oxidase activity of enzyme preparations.

Abstract: containing 1 ml. 15 % glycerol solution, 1-0 ml. 0-1 M-sodium acetate, 0-5 ml. 0-3 M-bicarbonate solution and 0 5 ml. of the enzyme solution. Occurrence of the back reaction would have given rise to an uptake of C02 from the system, but in fact no such uptake was observed. Under these conditions, therefore, no back reaction takes place, so that the incompleteness ofthe de-esterification cannot be due to the existence of an equilibrium between the back and forward reactions. A crude acetone-powder preparation from liver, which contained an active esterase, had no pectinesterase activity when tested by the manometric method. Consequently, liver esterase has no pectinesterase activity under these conditions, although the enzyme preparation from Ps. prunicolca has an esterase action on glycerol esters. This could, however, be due to the presence of esterases in the crude enzyme preparation, although the non-inhibition by diiwopropyl fluorophosphonate does not support this view (see below). Inhibitors. The rate of C02 output remained unchanged in the presence of0.01 M-copper sulphate, potassium cyanide, ferrous sulphate, sodium azide and iodoacetate. A final concentration of 0-0001 Mdiisopropyl fluorophosphonate, which was sufficient to cause 100% inhibition of liver esterase, had a negligible effect on the reaction towards pectin and tributyrin. Tannic acid (0001 M), which is said to inhibit the action of pectinases (Kertesz, 1936), caused no inhibition of the pectin-esterase reaction. The enzyme and pectin solutions were submitted to dialysis against tap water and then distilled water, and the activity determined in the presence and absence of sodium chloride and sodium oxalate, which have been reported as being necessary for activation of the enzyme from tomatoes (Hills & Mottern, 1947). The velocity of the reaction was increased 20% by 0*05 M-sodium chloride, but was unaffected by 0*002 M-oxalate. Further work is being carried out on the pectinase enzymes produced by P8. prunicola, and on the separation of the pectin esterase and pectinase enzymes.

A comparative study of the succinic dehydrogenase-cytochrome system in heart muscle and in kidney.

Abstract: Most of our knowledge concerning the components of the system ofenzymes which catalyses the aerobic oxidation of succinate has been gained from studies ofthis system in enzyme preparations obtained from heart muscle. Since, in recent years, kidney has been used by many workers as the source of the succinic oxidase system, it seemed desirable to make a comparative study of this enzyme system in kidney and heart muscle. Such a comparison seemed especially necessary in view of the statement of Keilin & Hartree (1940) that kidney (as well as liver and other organs) doss not contain a normal cytochrome b, which is an essential component of the succinic oxidase system in heart muscle. This paper describes a study of the succinic oxidase system in the two tissues, using both manometric and spectroscopic methods. A preliminary account of some of these findings has appeared elsewhere (Slater, 1948).

The measurement of glucuronide synthesis by tissue preparations.

Abstract: To measure the ability of surviving tissue slices to form glucuronides of compounds such as menthol and phenol, Lipschitz & Bueding (1939) determined ether-soluble compounds giving the Tollens colour reaction for glucuronic acid. Whilst this procedure yielded valuable information in their hands, it is inconvenient for routine purposes, and the lack of specificity in the colour reaction can be a serious disadvantage. It must also be borne in mind that not all glucuronides are as ether-soluble as that derived from menthol. De Meio & Arnolt (1944), in their study of phenol conjugation by tissue slices, assumed the figure for combined phenol given by the method of Theis & Benedict (1924) to represent phenylsulphuric acid and phenylglucuronide. As shown below, it is doubtful whether the results of De Meio & Arnolt (1944) have any bearing on the problem of glucuronide synthesis. It was considered that the study of the biological mechanism of glucuronide formation required a sensitive reaction, specific for a glucuronide in the presence of a large excess ofthe hydroxy compound. Following a suggestion made by Dr R. T. Williams (private communication), the possibilitywas investigated of determining o-aminophenyl-fl-D-glucuronide (Williams, 1943) in the presence offree o-aminophenol by the reaction described by Bratton & Marshall (1939) for the estimation of sulphonamides. If the reaction was carried out according to their directions, in strongly acid solutions, the bluish pink given by the glucuronide was slow to develop, and when it had reached its full intensity an appreciable colour of similar shade was seen in parallel experimentswith the free phenol. By careful control of pH it was found possible, not only to shorten the period for complete colour development with the glucuronide, but to eliminate interference by free o-aminophenol. To avoid having to adjust the pH of the solution after removal of proteins, methods of protein precipitation at the pH chosen for colour development were studied. Application of the complete procedure to the measurement of glucuronide synthesis by mouse-liver slices is described below.

Distribution of glutamine and glutamic acid in animal tissues.

Abstract: It is generally accepted that glutamine and glutamic acid, apart from serving as structural units in proteins and peptides, play a special role in the metabolism ofanimals, plants and micro-organisms. A few specific functions have already come to light (see the reviews of Archibald, 1945, 1947), but it is probably correct to say that the chief functions are still unknown. It was thought that a survey of the occurrence of glutamine and glutamic acid in biological material might assist in elucidating the part played by the two substances in metabolism, and the two substances were, therefore, determined in a number of animal tissues. Surveys of the distribution of glutamine have been made by previous workers (Ferdman, Frenkel & Silakova, 1942; Hamilton, 1945), but data on the glutamic acid content of tissues are scanty because, until recently, no specific and convenient methods applicable to small quantities of material were available.

Enzyme activities in the blood of infants and adults.

Abstract: Morphological studies of the blood of infants and adults have been fairly numerous, but functional or chemical comparisons havebeenrare. The circulating blood at birth has been shown to contain two kinds of haemoglobin, an infantile type which comprises four-fifths of the whole and which is relatively resistant to alkaline denaturation, and the adult type which makes up the remainingfifth (Haurowitz, 1930, 1935; Brinkmann & Jonxis, 1935). Immunological differences between the adult and infant haemoglobins were detected by Darrow, Nowakovsky & Austin (1940). Whitby & Hynes (1935) found that concentrations ofsodium chloride, which caused no haemolysis of adult red cells, readily haemolysed a proportion of the cells of a sample of infant blood. A concentration of sodium chloride, however, sufficiently dilute to cause total haemolysis ofnormal adult cells, did not disrupt all the cells in a sample of infants' blood. Such samples therefore contained some cells which were more and others less fragile thannormaladult cells. Mollison (1948) comparedthe survival time in the infant circulation of red cells taken from cord blood with that of cells taken from an adult vein. He found that cord red cells disappeared at nearly twice the rate of the adult cells during the 10 days following transfusion. Stevenson (1943) estimated the carbonic anhydrase activity of infant and adult red cells and found it to be low in the former, and still lower in red cells obtained from premature infants, and Anselmino & Hoffimann (1931) claimedthat the catalase activity ofred cells derived from full-term infants was higher than that of maternal red cells. If all the morphological, physiological and chemical evidence is taken together itwould appear that the red cells ofan infant are a more heterogeneous population than those of an adult. The present work was undertaken to compare the enzyme activities of the serum and erythrocytes of the newborn and adult human. The true and pseudocholinesterase of the serum have been investigated, and in the erythrocytes true cholinesterase, glyoxalase, carbonic anhydrase, catalase and acid phosphatase.

The oxidation of catechol and homocatechol by tyrosinase in the presence of amino-acids.

Abstract: Axelrod, A. E. & Elvehjem, C. A. (1939). J. biot. Chem. 131, 77. Axelrod, A. E., Madden, R. J. & Elvehjem, C. A. (1939). J. biol. Chem. 131, 85. Bandier, E. & Hald, J. (1939). Biochem. J. 33, 264. Elliott, K. A. C. & Libet, B. (1942). J. biol. Chem. 143, 227. Govier, W. M. & Jetter, N. S. (1948). Science, 107, 146. Handler, P. & Klein, J. R. (1942). J. biol. Chem. 143, 49. Harden, A. & Young, W. J. (1906a). Proc. Roy. Soc. B, 77, 405. Harden, A. & Young, W. J. (1906 b). Proc. Roy. Soc. B, 78, 369. Kornberg, A. (1948). J. biol. Chem. 174, 1051. Krebs, H. A. & Eggleston, L. V. (1940). Biochem. J. 34, 442. MoIlwain, H. (1947). Advane. Enzymol. 7, 409. M¢Ilwain, H. & Hughes, D. E. (1948). Biochem. J. 43, 60. Mann, P. J. G. & Quastel, J. H. (1941). Biochem. J. 35, 502. Martinek, R. G., Kirch, E. R. & Webster, G. L. (1943). J. biol. Chem. 149, 245. Melnick, D. & Field, H. jun. (1940). J. biol. Chem. 134, 1. Mitchell, H. K. & Isbell, E. R. (1942). Publ. Univ. Texas, no. 4237, p. 37. Perlzweig, W. A. (1947). Biol. Symp. 12, 204. Quastel, J. H. (1939). Physiol. Rev. 19, 135. Schlenk, F. (1945). Advanc. Enzymol. 5, 207. Spaulding, M. E. & Graham, W. D. (1947). J. biol. Chem. 170, 711. Taylor, A., Pollack, M. A. & Williams, R. J. (1942). Publ. Univ. Texwas, no. 4237, p. 41. Teeri, A. E. & Shimer, S. R. (1944). J. biol. Chem. 153, 307. Umbreit, W. W., Burris, R. H. & Stauffer, J. F. (1945). Manometric Techniqumes. Minneapolis: Burgess. Warburg, 0. (1924). Biochem. Z. 152, 309. Warburg, 0. & Christian, W. (1936). Biochem. Z. 288, 291.

The inhibition of β-glucuronidase by saccharic acid and the role of the enzyme in glucuronide synthesis

Abstract: In view of the relationship shown to exist between the fi-glucuronidase activity of a tissue and its state of growth (Levvy, Kerr & Campbell, 1948), it was considered important to find a specific inhibitor' for this enzyme. It has been suggested (Fishman, 1940), without any direct evidence, that fl-glucuronidase is responsible for the formation of glucuronides in the body. The use of an inhibitor for glucuronidase in testing this hypothesis forms an obvious first step towards elucidating the physiological function ofthe enzyme. A variety of substances have been examined for their effect on the hydrolysis of phenylglucuronide byf-glucuronidase. Ofthosewhichcausedinhibition, by far the most effective was D-glucosaccharic acid, and this compound was examined for its action on glucuronide synthesis by liver slices and on growth processes in the mouse.

Some observations on astaxanthin distribution in marine crustacea.

Abstract: Grayson, J. M. & Tauber, 0. E. (1942). Iowa St. CoU. J. Sci. 17, 191. Junge, RI. (1941). Hoppe-Seyl. Z. 268, 179. Kuhn, R. & Lederer, E. (1933). Ber. dt8ch. chem. Ge8. 66,488. Kuhn, R., Lederer, E. & Deutsch, A. (1933). Hoppe-Seyl. Z. 220, 229. Kuhn, R. & Sorensen, N. A. (1938). Z. angew. Chem. 51,465. Kuhn, R., Stene, J. & Sorensen, N. A. (1939). Ber. dtsch. chem. Ge8. 72, 1688. Lederer, E. (1935). Le8 Carotenoidew des Animaux. Pars: Hermann. Mann, T. B. (1943). Analyst, 68, 233. McCay, C. M. (1938). Physiol. Zo6l. 11, 89. Morton, R. A. & Stubbs, A. L. (1946). Analyst, 71, 348. Okay, S. (1947). Ref. Fac. Sci. Istanbul. 12, 1. Okay, S. (1948). Proc. Int. Congr. Zool. 13 (in the Press). Palmer, L. S. & Knight, H. H. (1924). J. biol. chem. 59, 443. Wald, G. (1943). Vitamisw and Hormones, 1, 195.