Showing papers in "Biochemical Journal in 1943"

The estimation of creatine and of diacetyl.

Abstract: Voges & Proskauer [1898] observed that when strong alkali was added to broth cultures of certain species of bacteria there developed, after an interval of time, a pink colour. Subsequently the work of Harden [1906] and of Harden & Norris [1911] established that the chemical reaction responsible was one between diacetyl and creatine (or certain similar substances). Attempts to make the reaction quantitative [Walpole, 1911; Eggleton & Eggleton, 1928] were only partially successful. The reaction was further studied by Duliere [1929], Lang [1932] and Muller [1935], but it was the discovery by Barritt [1936], that o-naphthol greatly intensifies the colour, which made it possible for the first timne to use this reaction as a means of estimating either creatine or diacetyl. The present paper presents some additional facts about the reaction and methods of estimation based on it.

The vitamin A content and toxicity of bear and seal liver.

Abstract: OBITUARY NOTICE I943 hexose-diphosphoric acid; and to Harden and Young we owe the conception of the co-ferment as a substance comprising both the phosphate radical and an organic residue of unknown structure capable of passing on the phosphate radical to the sugar molecule. In temperament the two colleagues differed greatly, Young's enthusiastic nature contrasting with the reserve and caution which were characteristic of Harden. Young was an active partner in the work and certainly played no inconsiderable part in its development. In 1912, a new Institute of Tropical Medicine had been established at Townsville, Australia, and a selection Committee was appointed in London under the Chairmanship Qf Dr C. J. M. Martin to appoint certain members of the Staff of the new Institute. Young was chosen as the Biochemist, and in 1912 Dr and Mrs Young with their daughter Sylvia left London to make a newhome in Australia. Whilst at Townsville, Young took up the question of the alteration in metabolism produced by residence in the tropics, and some new observations were recorded in a series of papers published between 1915 and 1920, chiefly in the Annals of Tropical Medicine and Para8itology. In 1919, in collaboration with Dr Breuil, pathologist at the Institute, an interesting paper on Tropical Australia and its Settlement was written and appeared in the Medical Journal of Au8tralia. Chiefly owing to the exertions of Prof. W. A. Osborne, who had just left Townsville to take up tho Chair of Physiology at Melbourne University, a Lectureship in Biochemistry was established at that University and offered to Young: somewhat later a Chair in Biochemistry was founded to which Young succeeded. In Melbourne, Young's time was chiefly devoted to teaching; he was responsible for the instruction in this subject of students in the faculties of agriculture, dentistry, medicine, science and veterinary science; he built up a fine department, and in it were also carried out various investigations for the Government, two of especial interest dealing with the storage of fruit and the ripening of bananas. Young was a man interested in many aspects of life. He was widely read in English literature, with a good knowledge of the drama of the Elizabethan age; he was alsp an expert but entirely self-taught cabinet maker. Whilst at the Lister Institute, he took up golf with his usual zeal and was to be found on summer evenings assiduously practising at Wimbledon Park. His colleagues at the Lister Institute remember him as an excellent friend, always good-tempered, interested in everything, and generally ready to argue on either side of the topic under discussion. Within a period of two years the Biochemical Society has to mourn-the loss of Harden, Robison and Young, the three men who did so much to unravel the mysteries of carbohydrate chemistry and to throw open this fruitful field to later investigations. I. S.-M.

Studies in immunochemistry: 7. The isolation from hog gastric mucin of the polysaccharide-amino acid complex possessing blood group A specificity.

Abstract: 1. The kinetics of the reaction between HCHO and I-ascorbic acid or chemically related substances have been studied. 2. Indirect evidence is produced for the possible structure of the HCHO-1-ascorbic acid complex. / 3. Lugg's method for determination of I-ascorbic acid has been examined from the point of view of the above experiments, and necessary precautions are stressed. 4. Suggestions for other methods for the determination of I-ascorbic acid in the presence of reductic acid and reductone are advanced.

A study of the excretion of organic antimonials using a polarographic procedure.

Abstract: other mixtures, e.g. of C22H4402 and C24H4802, which have been examined [Chibnall, Piper & Williams, 1936], show too many irregularities to be used for direct comparison. Some estimate of the nature of the impurities present may, however, be made by correlating the X-ray measurements with the general observations made by Chibnall et al. [1936] on the behaviour of fatty acid mixtures. For this purpose measurements had to be made of both the B and C polymorphic modifications, the X-ray photographs usually being taken of samples pressed lightly on to glass slides. A. The original preparation, when recrystallized from acetone, showed X-ray lines corresponding to the C modification alone. On recrystallization from benzene and from acetic acid, preparations were obtained, both of which showed lines due to B and C modifications on the same photograph. Such behaviour was noted by Piper and co-workers [Chibnall et al. 1936] in the binary mixture containing 2.5-10% and 80-90% of the lower constituent. Here the C spaci#g is slightly lower, the B spacing slightly higher than, the best values for pure C22H4402 . Both these types of spacing change may be due to mixture of a small quantity of C20H4002, say 2-5-10%, with C22H4402, but it seems very probable that the fraction still contains traces of other acids, particularly C24H4802. IIIR5. This fraction, when recrystallized from methanolethyl acetate, showed the B spacing alone. While the spacings. both of this, and of the methyl ester, are intermediate between those of C22H4402 and C24H4802, the data do not fit very well with the observations that have been made on mixtures of synthetic C22114402 and C24H4802, so that the mixture is presumably more complex.

Phosphorolysis and synthesis of glycogen in animal tissues.

Abstract: ,Our experiments suggest that when the blood sedimentation rate is raised, there is no alteration in the chemical structure of the proteins. A possible exception to this is the Bence-Jones protein [Devine, 1941]. Geottsch [1936] found that nephritic total globulin was immunologically different from the normal, and Alving [1936] found changes in the cystine content of total albumin in nephrosis. Hewitt [1938b] later showed that in both cases the individual fractions of globulin or albumin give normal chemical and immunological reactions, and the altered ratios are responsible for the abnormality of the plasma.

The utilization of urea in the bovine rumen. 3. The synthesis and breakdown of protein in rumen ingesta.

Abstract: 1. In the utilization of urea by dairy cattle the first stage is probably the conversion of urea to NH3 in the rumen. Moreover, the urease activity of the rumen ingesta is so great at all times of the day, whatever the time of feeding, and remains so little affected by relatively large apaounts of urea, that all the urea ever likely to be fed, even to a high yielding cow in full lactation, would readily be converted to NH3 within 1 hr. This fact has been confirmed by Wegner, Booth, Bohstedt & Hart [1941], who found a marked increase in N.P.N. and NH3 in the rumen after a urea meal but were unable to detect urea itself. 2. The urease of the rumen resembles, in activity, that from soya and jack beans. Changes in its activity with changes in temperature and pH, and its behaviour in the presence of such inhibitors as quinone and NaF, are typical of enzymes of the urease type. Preliminary attempts to obtain enzyme preparations free from bacteria have, however, proved unsuccessful.

The effect of citrate on the rotation of the molybdate complexes of malate, citramalate and isocitrate.

Abstract: Extracts of liver and muscle convert citric acid into laevo-rotatory isocitric acid [Martius, 1938]. As the rotation of isocitric acid, like that ofother ac-hydroxy acids, is much increased by (NH4)2MoO4*, the polarimeter can be used to measure low concentrations of isocitric acid in tissue extracts [Martius, 1938; Jacobsohn, 1940]. On applying this method to plant extracts we met with an unexpected complication. Aqueous extracts of rhubarb petioles showed a dextrorotation with molybdate, owing to the presence of ()malic acid. When the extracts were mixed with citrate the dextrorotation increased very considerably, e.g. from + 1.750 to + 3.25°. Investigation of this effect showed that the increase was not caused by an enzymic process; it proved to be due to an effect of citrate on the dextrorotation of the 1(-)malate-molybdate complex. Underthetest conditions [o]c' was + 7160 for 1(-)malic acid in the presence of (NH4)2MoO4 and + 13400 for l()malic acidl in the presence of (NH4)2MoO4 and citrate. Citrate was found also to change the rotation of the molybdate complexes of two substituted malic acids, viz. citramalic and isocitric acids. The effect of citrate on the rotation of the malatemolybdate complex has already been observed by Auerbaoh & Kruger [1923] who realized that citrate interferes with the polarimetric determination of malic acid. Obviously citrate also interferes with the Martius polarimetric isocitric acid estimation. Isocitric acid is frequently accompanied in biological material by citric acid and many of the data calculated from polarimetric readings by previous authors therefore require revision.

The reduction of methaemoglobin by ascorbic acid.

Abstract: In idiopathic methaemoglobinaemia, of which we have investigated'some cases, the occurrence of an atypical form of methaemoglobin' abnormally resistant to reduction has been postulated by Lian, Frumusan & Sassier [1939] as an aetiological factor. It thus became of interest to examine the evidence which has been put forward by Vestling [1942] against the unitary view of methaemoglobin. This author found that methaemoglobin made from haemoglobin by the action of nitrite was much less readily reduced by ascorbic acid than methaemoglobin formed by the action of ferricyanide, and suggested that these two spectroscopically similar products [Austin & Drabkin, 1935] differed chemically. The reaction is also of interest because it has been applied clinically by Deeny, Murdock & Rogan [1943] in the treatment of idiopathic methaemoglobinaemia. The experiments reported here indicate that there is no chemical difference between nitriteand ferricyanide-prepared methaemoglobin, so far as reduction by ascorbic acid is concerned, and that the differences observed by Vestling are due to the presence of ferrocyanide.